Today, in this third lecture of this series, we will look at some of the jet engines that have developed over a period of last 60 years and have powered various kinds of aircraft flying around the world. This is generally referred to as jet propulsion. The basic concept of jet propulsion comes from the simple concept or idea that if you have a device in which a certain amount of working fluid and in our case, this working fluid is almost invariably air and as a result of which all jet propulsion devices that we are talking about are essentially air breathing engines. These air breathing engines have a propulsive method by which this is illustrated in this picture. In this method, the air is inducted into a propulsive device and this working medium is then accelerated through the device and the air is exited from the device with a slightly higher velocity. As a result of this, the working medium actually acquires a change of momentum. This change of momentum is what finally manifests itself in the form of force or more specifically the action of the exhaust jet from the propulsive device creates the reaction which is the propulsive force or what we would more specifically be always referring to it from now onwards as thrust. The thrust is a result essentially or a reaction to the change of momentum that occurs across the propulsive device. This is the basic understanding on which all propulsive devices that we are looking at today would be essentially based on. Now, this requires that the air which is again our working medium going into the propulsive device has certain properties in terms of pressure, temperature and velocity. It goes out with another set of properties again another set of pressure, temperature and velocity and a change of these properties is what produces the change of momentum. Now, basically the change of momentum that we are looking at refers to the change of velocity. Velocity as you know has a magnitude and a direction and the direction is as shown in this picture. In the same line that means the incoming velocity and the outgoing velocity are exactly in the same line and as a result of which the action of the exhaust velocity and the reaction produces a thrust in the same line in which the velocities have come in and gone out and as a result of which a thrust is produced in the line of action of the production of exhaust velocity or exhaust jet more specifically. Now, as you can see in this picture here the flow goes out with a certain pressure which is more specifically static pressure and this pressure if we call it let us say P e as the P exit pressure may be equivalent or may be different from the pressure that is existing outside in the atmosphere which we refer to let us say as P a. Now, in this particular instance at this moment we are considering that the pressure exit pressure has indeed reached the atmospheric pressure P a by the time it exhaust from the propulsive device as a result of which at the phase marked e at that particular station the difference between the two pressures is 0 and hence what we get a thrust dependent only on the change of momentum and is often referred to simply as the momentum thrust. Now, this is a very ideal condition we shall see later on just a little later today that in case your exit pressure P e happens to be different from the atmospheric pressure P a we would have a thrust value which would look somewhat different from what we are looking at right now we will come to that in a few minutes. Let us look at a real propulsive device what we had just looked at is a ideal concept of a propulsive device if you look at a real propulsive device or what more specifically can be called a gas turbine based turbojet engine we have number of components here we have as usual the air coming in we have the air coming in from this end that is often referred to as the intake and this component here is a common element in all kinds of jet engines that you have to have some kind of a intake at some point of time later on maybe we will discuss the importance of this intake and then the flow goes through a process of compression through a compressor. So, this is a compressor and in which the flow actually gets compressed or the pressure actually goes up and then we have a combustion chamber in which the flow actually acquires burning fuel. So, the fuel is burned into the air and a mixture of burned fuel and air then is passed on to the turbine now turbine extracts work from this hot and compressed air or gas and part of the work that it extracts is now passed on through the shaft on to the compressor. So, the turbine takes out certain amount of energy in the form of work and runs the compressor and compressor does the compression passes on to the combustion chamber. So, there is a energy loop here. So, through the turbine and compressor certain amount of energy is continuously looping this is necessary for sustenance of this engine. So, certain amount of energy that is actually in the gas over here is used to continuously sustain this loop balance of the energy that is available now which is hot and which still has sufficient amount of pressure is now passed on through various kind of ducting system and then finally, through jet nozzle which then exhaust the flow in a jet with a high velocity. Now, the engine that is shown here you can see here an element called after burner we will probably have a chance to discuss the details of this a little later as the name suggests you have another round of fuel burning over here and the temperature of the gas this gas may be raised to even higher values and then only it is exhausted through the nozzle and as a result of which quite often you end up getting a higher amount of thrust. So, these are additional options that some of the jet engines have not all the jet engines many of the jet engines do not have any after burner. So, this is an optional item quite often it is used during for the military aircraft engines and most of the civil aircraft engines do not have any kind of after burner. So, this is a kind of a sketch or a layout of a real engine in which it passes through various components let us go through them quickly again you have a compressor you have a combustion chamber which actually burns the fuel and inputs the energy from outside and then you have the turbine and then it goes through a jet pipe and then through exhaust nozzle at the end of which you have a net increase of velocity and more specifically note net increase of momentum of the air that has come in. As you can see once the air comes in through the intake it has nowhere else to go it has to go through all the components and exit through the nozzle it has nowhere else to go. So, the amount of air or the mass of air that comes in here would be approximately same with the addition of fuel there will be little more that exist finally from the propulsive device that is through the nozzle and that produces the change of momentum and this change of momentum produces the action which of course as we have discussed produces the reaction which creates a thrust. So, this is the process through which a real engine actually operates we shall be talking about these processes more and more as we go along. The understanding now we have from the previous diagram and from the present diagram is that a certain amount of air mass is captured it is processed through various processes and then it is exhausted in a jet at a higher velocity with a higher momentum and that creates a thrust. Now, this is the understanding with which we have based our idea that the thrust can be created through the action reaction process it is easier to understand it that way it is easier to put it in simple mathematical form as we can see here you can write down the thrust equation here based on the mass flow as we are talking about and the change of velocity from intake velocity or air velocity to the exit velocity and that gives you fairly accurate mathematical estimate of the thrust that may be produced by the propulsive device and in this particular case a particular engine. However, the actual thrust production of a real engine often happens in a slightly different way conceptual basis of change of momentum as I mentioned is the easier way of understanding. However, actual method by which the thrust is produced is slightly more intricate. Let us go through again a sketch which is a representative of a real engine. We have air flow again coming through an intake we have a compressor over here through which the flow undergoes certain amount of compression. So, at the end of the compression process this air actually has a very high pressure at this point. So, at this station the air has very high pressure for the same mass. Now, simple fluid statics will tell you that if air or any fluid has a higher pressure at this station it will exert a pressure or a force across this body from this side to that side and that is what is shown here. So, at the end of the compression process the entire body of the compressor which is a solid mass actually made of blades would experience forward force which is shown by the arrow over here and then the air actually goes through process of combustion in which the fuel is burnt inside which the air undergoes again some change in temperature some change in pressure. As a result of this change of temperature and pressure at the station over here it is very likely now that the air or the gas at this moment with the burnt fuel would have pressure and temperature that are quite different from the pressure and temperature that came in over here. Now, the collective pressure that can be integrated over this surface let us say can give you pressure that is a net pressure that may be acting in the forward direction that may jolly well be acting in the backward direction too. So, the combustion chamber here if you integrate the pressure over the entire surface of the combustion chamber you would probably get a net pressure acting over this entire volume which could be in the forward direction or it could actually be in the backward direction. And then of course, the air is exited to the turbine which does the work and which supplies to the shaft work to the compressor. Now, this turbine through the turbine what happens is the work is extracted. As a result of extraction of the work the air actually loses certain amount of temperature and pressure. So, the pressure at this end of the turbine is substantially lower than the pressure at this end at the forward end. So, the air mass actually exerts again from fluid statics the air mass would exert a certain amount of pressure through the body of the turbine and that exertion of pressure or force a net pressure over the entire area would be a force and that would be in the backward direction. So, the turbine essentially produces a backward force while operating inside an engine. Now, as the flow is exited from the turbine with the remainder of temperature and pressure it passes through a jet pipe and then it passes through a nozzle and it exist from the entire propulsion device or engine over here. And in the process it of course, has a pressure over here which is quite different from the pressure over here and one can very well imagine that the pressure over here would be substantially less than the pressure over here. So, this difference of static pressure again from fluid statics is most likely to create a pressure field which net pressure of which would be acting in the backward direction. Now, as a result of this the net of all these forces if you take you have a certain amount of force that is acting in the forward direction which we could call forward thrust and there is certain amount of force which is acting in the backward direction which we would call probably rearward thrust and the net of the two is what we would call net thrust. So, as you can see here in this diagram all the components that are part of the engine actually participate in the process of creation of thrust. And our understanding that the momentum difference between here and the end station, last station here gives the thrust is essentially a concept it is a very handy and convenient way of estimating the thrust quite often reasonably accurate. However, a more accurate and more detailed measurement or estimate of thrust can be obtained only after we have all these components rather accurately determined. And the final value of the net thrust from here should be pretty close to the estimate that we had made earlier on the basis of net change of momentum. So, this is the mechanism by which the thrust is actually created inside a jet propulsion device. Let us now look at the equation that we were talking about the thrust equation. We had seen the first part which constituted what we had called the momentum thrust. The first part of the momentum thrust can be called the gross momentum thrust which is the action reaction principle at the exit of the propulsion device or the engine. This is normally the component which is produced by the incoming flow and this is often referred to as the intake ram drag. So, the difference of the two is the net thrust that is normally produced by any propulsive device because of the change of momentum. So, this is the incoming momentum, this is the outgoing momentum and the difference of the two is the net momentum thrust. Now, as I mentioned in the earlier diagram, if you can quickly go back the pressure over here need not always be same as the atmospheric pressure or the ambient pressure that is existing in the atmosphere. If the pressures are different and in many operating conditions of the engine, it is entirely possible that this pressure would not be same as this pressure. As a result of this difference, if it is a positive difference, the area at the exit of the engine or the propulsive device multiplied by the difference in the pressure gives you a force and this is what we call pressure thrust. Now, this pressure thrust normally then comes into existence when the net pressure at the exit phase is not equal to the atmospheric pressure. Now, from this equation, it would seem that this is some kind of an additional thrust that is coming into picture. One needs to understand that this pressure thrust actually appears when this velocity, the exit velocity is not at its maximum. And a remainder of the energy, kinetic energy that is being produced through these propulsive device appears as a thrust, as a pressure and gives you pressure thrust.  And quite often, if you quantify the values, you would probably find that the total thrust inclusive of the pressure thrust would actually be a little less than the maximum momentum thrust that you can get when the exit pressure is equal to the atmospheric pressure. And this is when the flow is said to have completely expanded through the nozzle. That means, the nozzle has completely used up the all the kinetic energy that is available, all the energy that is available into velocity, into kinetic energy, all the sorry all the potential energy that is available into kinetic energy. And as a result of which, the pressure over here now equals to the atmospheric pressure. Now, the engine designer has to be very careful in designing the nozzle to ensure that under no operating condition, the exit pressure P e should be less than the atmospheric pressure P a, because if that happens, we are going to have a negative component over here and we are actually going to get a negative thrust. Now, that is obviously not a very desirable thing to happen and as a result of which, it is necessary that the engine design, specifically the nozzle design is made such that under all operating condition, pressure thrust that is produced is either positive or 0, but never negative. Quite often, the engine designers try to keep a small margin and as a result of which, you always get a small pressure thrust, but never a negative pressure thrust. The other parameter, which often defines the action of a propulsive device is simply refer refer to as propulsive efficiency. Now, propulsive efficiency, which we had a look at in the previous lecture can be formally defined now as a ratio of the useful propulsive energy that is available at the end of the propulsive process to the thrust power that is produced and that if you take the ratio to that of the energy that is used and unused kinetic energy of the jet. Now, when the jet is going out of the propulsive device, a certain amount of energy is spent through the process of the exhaust process and this kinetic energy is a lost cause and as a result of this, a large amount of energy in the form of kinetic energy is exiting the propulsive device without getting any work done out of it. Now, that as I mentioned is a lost cause. So, propulsive efficiency tries to capture how much of the energy that is available at the end of the propulsive process that is the useful propulsive energy and how much of that is used and how much of it has actually been left unused and a ratio of these two finally gives you the propulsive efficiency. Just to explain that the kinetic energy that is going out of the jet, this is often referred to as the kinetic energy relative to the earth, which with reference to the moving aircraft is considered a stationary body. So, the formal definition of the propulsive efficiency can now be written down as this is the thrust power which we are written down here and thrust being now expressed in terms of power and this is the energy that is available. So, this is again the thrust power and this is the energy with which the flow is going out of the entire propulsive device and this energy will not be available for any propulsive purpose anymore once it exits the propulsive body. Then simpler derivative of this full form appears in the form very simple form over here. As you can see here the propulsive efficiency is thus dependent solely on the ratio between the exit velocity and the entry velocity of the working medium that is air and that clearly gives us a quick and handy idea what is the efficiency with which this propulsive device is most likely to work. Now, the fallout of this very simple propulsive efficiency definition actually tells us of few stories. Let us see what actually can be extracted from this very simple definition of propulsive efficiency. If for example, our exit velocity is rather large compared to the entry velocity of the air that means a very large change of velocity or a large amount of acceleration has occurred through the propulsive device and quite often that happens with a rather low mass flow. You could get a reasonably good amount of thrust produced, but in such a case in such a case the propulsive efficiency is going to be low because this ratio is now rather big and the denominator here is going to be much higher than the numerator which is 2. The propulsive efficiency thus would come out to be somewhat on the lower value and this is typical of a jet engine in which normally a large exhaust velocity is observed and a jet engine operates with a comparatively low mass flow, but still produces a reasonably good amount of thrust and that is why the jet engines are so attractive, they are compact and small produce a large amount of necessary thrust. However, we have to keep an eye on the fact their propulsive efficiency is not actually very high, they may compact thrusters, but they are not very high in propulsive efficiency and we shall see later on that this propulsive efficiency does have an impact on the fuel efficiency that everybody is so concerned with. The other end of the picture is supposing when the exit velocity is equal to or let us say almost equal to the entry velocity V a, then the definition tells us that numerator will be equal to the denominator both would be 2 and as a result of which your propulsive efficiency is actually going to be 100 percent or very close to 100 percent. However, if that happens from the earlier equation over here assuming that this pressure thrust is 0 the thrust produced would actually be pretty close to 0 that means when the propulsive efficiency is 100 percent the thrust produced would be 0 obviously, such an engine is of no use to us. The solution is that if you have a very small change in the velocity which operates on a very high mass flow then a substantial amount of thrust can be produced. So, the we now turn our attention to the mass flow and not the change of velocity and if we can have a propulsive device when the operative mass flow is very high in such a case you can produce a requisite amount of thrust a substantial amount of thrust and that thrust production mind you now is going to be with very high propulsive efficiency. Now, this is obviously a very desirable phenomenon where your fuel efficiency is going to be quite good and this is the kind of engine that normally we can see in propellers when we operate with propellers. Propellers typically operate with low acceleration operate with very high mass flow and operate with very high propulsive efficiency and if you have a turbo fan which is a normal jet engine these days a large part of the thrust is produced this way that means with a very large mass of air going through a very small change in velocity working with very high propulsive efficiency and comparatively small part of the thrust is produced by the jet effect which has a large change in velocity and operates with a comparatively smaller propulsive efficiency. So, combination of these two is what we see today in the form of turbo fans and judicious mix of the two would give you overall propulsive efficiency which would be quite good. This graph here now tries to capture the various kinds of propulsive efficiency variations with flight Mach number for various kinds of engines or propulsive devices. If you look at this graph now the turboprop engine which as I mentioned operates with a high mass flow and a small change in momentum operates with a high propulsive efficiency almost through its entire operating range and somewhere over here it starts dropping when the flight Mach number is high or high subsonic and the reason we had mentioned was that the propellers tend to go supersonic which produces a low propulsive or a propeller efficiency. The turbo fans on the other hand has a good propulsive efficiency only at high values. Now, turbo fans as I mentioned is a mix between pure turbojet and a certain aspect of turboprop or a propeller and a fan is essentially somewhere in between a propeller and a pure compressor and the size of the fan is such that it is somewhere in between in terms of size and as a result in a turbo fan as I mentioned in the previous slide it operates with a high mass flow through the fans and produces a high propulsive thrust and a small mass flow as a jet and produces a low propulsive thrust and combination of the two gives us turbo fans which are generally of higher propulsive efficiency and as a result of which these turbo fans become more and more competitive at a higher mass flow and at a high subsonic mass flow these turbo fans are clearly the more efficient and more desirable propulsive devices and that is the reason why most of the aircraft today fly with turbo fan engines. The turbo jets are often referred to as the pure jets operate with as we have seen rather low propulsive efficiency. However, as we can see here when you need very compact engine especially in very high speed aircraft you do not have a choice but to go for the compactness of the engine because the turbo fans and the turboprops they tend to be very large in size and when the size is really the most important thing you have to have a very small sized engine quite often to be put inside an aircraft in a supersonic aircraft you need turbo jets. So, when the Mach number of the flight is clearly more than one in supersonic aircraft the choice often goes back to the turbo jets or pure jets in which you can get substantial amount of thrust in a compact engine. However, let us remember their propulsive efficiencies are never going to be very good. So, in case of supersonic aircraft we consciously go for turbojet engines because of their compactness knowing fully well their propulsive efficiencies are going to be somewhat on the lower side in comparison to the other kinds of propulsive devices which are the turbo fans and the turboprops which as I mentioned are often used in the lower Mach number ranges. Let us look at various kinds of jet engines that are operational today in various kinds of aircraft. As we look at these various kinds of jet engines we shall be able to identify them for what kind of aircraft they are used these days. The first one that we have here is a very simple single spool bypass turbojet engine. Now, this operates on the principle that we have talked about it has a compressor and in this particular case it has a larger compressor and a smaller compressor. So, it has two sets of compressors on a single shaft and the two sets essentially due to slightly different functions. In the first set which sometimes people would like to call as fans air goes through them experiences compression and then gets split up in two parts. The outer part which is often referred to as bypass and hence forth we shall also refer to that as bypass flow and then this bypass flow actually goes over here bypasses the entire engine inner engine and that is why it is called bypass flow. It bypasses the entire inner engine and comes out towards the rear whereas a certain amount of flow goes through the inner compressor or the smaller compressors let us say gets compressed further. So, at the end of this process it has undergone a large amount of compression and then this highly compressed air is now taken inside the combustion chamber and then goes through the turbines which extracts the work and after this the hot gas and still highly compressed gas comes out from here and over here the cold bypass air and the hot gas mix up and then this mixture certain amount of length is given for them to mix properly and then this mixture of hot and cold which is finally exited from the exhaust nozzle. This is not so hot anymore and it is not so hot not so cold and it is a medium temperature gas now exhaust from this nozzle producing a net change of momentum across this entire device which of course as we know produces the thrust. So, this is the simplest form of bypass engine that came into being when it was realized that you could have a cold bypass engine and you could get some benefit out of the fact that certain amount of mass can be used to get thrust in a higher propulsive efficiency. The concept of propulsive efficiency has been brought into the picture that this bypass mass undergoes a small change in the energy and then this energy essentially produces a very small change in the thrust. However, here what we get is a mixed up thrust production if we consider the bypass as a separate entity it would actually produce it is in the process of producing by the time it is here thrust in a higher propulsive efficiency. So, the combination when it comes out actually produces thrust which is of a higher propulsive efficiency then if it had been a pure jet engine which would have had a higher exhaust velocity which means it would have had a higher temperature and higher kinetic energy at the exit and as I mentioned this higher kinetic energy would have been a complete loss. Now, the kinetic energy exhausting from here is of a lower value and as a result the amount of energy that is going out and that we can say is a lost cause is of a lower magnitude and hence the propulsive efficiency of this bypass engine is of a higher value than a pure turbojet engine and that is the reason why most of the engines today tend to be bypass engines. This of course is what we call a turboprop engine where one utilizes a gas turbine engine as we are talking about to drive a propeller. Now, propeller by now is our old friend propellers have been flying aircraft for last more than 100 years 107 years to be exact as of today and as a result of which they are useful devices and as we have seen from the propulsive efficiency point of view propellers are indeed the more efficient propulsive device within a certain flight Mach number. Now, as a result of which the propellers continue to be used in low flight Mach number aircraft. However, the rise of gas turbine engines is given as the option the propellers can now be driven by gas turbine engines which means you have air coming in over here going through the process of compressor combustion chamber turbine and then it produces a power separate power through the shaft in a let us say we can split the turbine in two sets one set is over here which drives the compressor supplies power to the compressor. There is another set over here which produces a very large amount of power and then this drives the shaft central shaft and runs the propeller through this gear box and as a result of which this is what we call a twin spool engine. It has two shafts two concentric shafts one which runs the basic engine comprising of the compressor combustion chamber and the turbine some people call it the core engine and the outer turbine or often referred to as the LP turbine or low pressure turbine operating at somewhat lower pressure than the HP turbine which operates at higher pressure this runs only this shaft and this shaft runs the propeller and the propeller produces the thrust a main thrust in case of turboprop engine propeller produces as much as 85 percent of the thrust 85 to 90 percent of the thrust a very small amount of thrust may be available through the jet that is coming out in the form of exhaust jet and this produces a very small amount of thrust in this engine the way it is designed right from the beginning the jet thrust that is available here and as we know now this will be produced with a very rather small propulsive efficiency and this is going to be very small whereas the large thrust which is produced by the propeller would be produced with very high propulsive efficiency a combination of these two is going to give you the total thrust that is produced by a typical turboprop engine. So, remember inner turboprop engine propeller produces the large thrust 80 to 90 percent of the thrust most of the time and the jet that you see here produces only a very small portion of the thrust typically 10 to 15 percent very rarely more than that now we can look at a little more of the bypass twin spool engine this is as opposed to the earlier bypass engine a twin spool engine which means is now has two shaft spool of course refers to the shafts it is a old terminology which people have used over the years and it refers to two shafts typically the two shafts are concentric there is a inner shaft which runs through and there is outer shaft which normally is used to drive the core engine which comprises the one turbine which is the HP turbine one set of compressors which is referred to as the HP compressor and hence this spool is referred to as high pressure spool or HP spool whereas the inner concentric shaft which runs right through is run through the low pressure turbine which is a set of turbines quite often and which powers through this shaft this big fan and sometimes a small compressor over here. So, this produces a large amount of power and it is often referred to as the low pressure spool. So, this mechanical arrangement that people have devised essentially creates two mechanical arrangements one which is the low pressure arrangement another which is the high pressure arrangement two mechanical arrangement. Now, this allows us essentially to run the two spools at two different rotating speeds or RPMs as a result of which most of the engines today the HP spool runs at a higher RPM and the LP spool runs at much lower RPM the reason for which we shall come to know as we go along and as a result of this independence of the two spools the designer now has the flexibility to design the two spools in a manner such that they independently operate at their best and most efficient operating condition one can well imagine and as we can as we will go more and more you would probably become familiar with these components and you would realize the this independence is very important for operating each of them at their best efficient operating conditions. There are a few other components that are very important for the efficient operation of a jet engine. The first thing is as I mentioned earlier every such jet engine has an intake now this is the kind of intake that all jet engines would have and flow comes in through it and hence why hence it is called an intake. Now design of this intake is a very intricate affair it is not simple and this shape of the intake over here often referred to as cowling is very important for the aerodynamic efficiency of the operation of this jet engine when it is flying with an aircraft in a high speed aircraft the design of this cowling appears in a very important issue in it appears in the design right in the beginning and it is a very long drawn out affair. The entire outer surface of the engine needs to be appropriately designed as you remember quite often in many of this aircraft that you may have seen this engine is seen to be hanging outside the aircraft quite often hanging from the wings and this entire outer surface is open to the air that is flowing. So, certain amount of air is coming in and that is going through the propulsive device to give you jet which creates a thrust there is a certain amount of air that is going outside flowing over the surface and this air actually produces drag that is additive to the drag of the aircraft itself and remember the thrust that is produced by this engine would have to overcome this drag for the aircraft to fly. Now we shall the engine designer has a job to make sure that the engine itself does not produce a large amount of drag and hence the outer shape over here and quite specifically over here is often referred to as both tail shape and this ensures that the external flow over this propulsive device does not produce a large amount of drag which as you know would have to be overcome by the thrust produced by this itself. Now towards the exit of this propulsive device as we have seen we have a cold bypass flow in this bypass engine and we have a hot inner flow or a core flow and then there is a mixing over here. This mixing needs to be done very uniformly so that the jet that comes out has a uniform temperature and pressure at the exit phase. Now this is very important and hence the design of this you know nozzle system over here all the way from here the shaping over here is extremely important in terms of aerodynamics and the gas dynamics because at the exit phase right over here we want absolutely uniform temperature and pressure profile because if the pressure profile is not uniform remember the thrust that is produced is not going to be a linear or thrust in the direction of the jet but it will be thrust produced which will have all kinds of components side wise or upwards or downwards components which will render the aircraft movement in the flight in various kinds of directions. As a result the aircraft will tend to have motions which could be a pitching motion which could be a yawing motion because the jet that is coming out here is not uniform and is not producing thrust that is unidirectional but producing multidirectional thrust. So the flow here needs to be extremely uniform as it is going out and hence the design of these components here is of great importance. Some of these things we will probably talk about more and more as we go along. The next kind of engine that we are looking at is high bypass engine as we have seen from the propulsive efficiency concept that the higher the bypass flow higher the mass of activation more is the propulsive efficiency. So we now know that this bypass flow acts in a manner that produces high propulsive efficiency thrust whereas the inner flow produces a low propulsive efficiency jet thrust. So more and more aircraft engines are being produced today which have high bypass flow and comparatively lesser amount of inner flow. This has a huge big fan and as we go along we shall see that these fans are getting bigger and bigger. This is ultra high bypass twin spool the fan has gone bigger and its size is now substantially bigger than the core engine. So much so that the fan needs to be run at a lower rpm and quite often they come with a gearbox. This gearbox is reminiscent of the gearbox that is used in propellers. So it is almost becoming the size of a propeller hence you need a gearbox to run this fan at a somewhat lower rpm so that they are mechanically and aerodynamically quite efficient and produces a thrust of a very high order through the bypass and as a result the overall propulsive efficiency now would be very high. This is a 3 spool bypass now it has 3 spools the inner shaft goes right through runs only the fan. We have a intermediate pressure compressor that runs through an intermediate shaft spool and then of course you have the HP spool which is the outer spool. So you have three shaft arrangement and some of the modern engines today do have these three spool arrangement. It gives the design of the independence of running three spools at three different rotating speeds or rpms and design them accordingly. This is a kind of engine that is used normally in flying helicopters and these are called turbo shaft engine. This is a typical two spool turbo shaft engine. These are used for running the propellers or the rotors of an helicopter. This is a twin spool power plant a variant of gas turbine engine often used in land based gas turbine in which intercooling is used that means between two sets of compressor the air is cooled down and then again compressed and this intercooling as we shall see later on through the process of thermodynamics produces a higher efficiency of the entire jet engine entire engine and this higher efficiency of the engine is often used in various power plants more specifically at this moment they are used in many of the gas turbine land based power plants with high efficiency operation. This is a kind of modern engine that is being designed today and likely to fly very soon and it is a three spool combination of engines where the main engine is two spool. The third spool comes out from here from this set of turbines and runs the pig fans which are now referred to as prop fans and these two prop fans have two gear boxes so that in some of the modern engines the second prop fan actually runs opposite in direction in rotational direction to the first fan and hence they are referred to as counter rotating prop fans they are behind the engine so they are often referred to as aft fans. So, these are the kinds of devices that are likely to fly very soon with various kinds of aircraft. This is a aft fan in which the fan is at the rear which is mounted actually on the turbines. So, the turbines are directly running the fan you do not have a shaft here and as a result of which the transmission efficiency here is almost 100 percent there is no shaft you know this is a two spool arrangement this is virtually the third shaft or third spool which are running independently of these two spools. This is a frontal view of a gear two spool very high bypass turbofan engine that is already being flown and you can see that the fan sizes are huge the size of this is huge each blade here is probably of the size of a full grown human being. This is a twin road or aft fan that is in test bed is being tested and as you can see here the twin aft prop fans and this is undergoing a test. This is a picture in which the twin road or aft prop fan is undergoing flight testing actually mounted on aircraft. So, as I mentioned some of these engines or flying devices you would be able to see a very shortly flying all around the world. We can say that at the end that the various engine development over the years that has taken place has produced more and more fuel efficient engine that starts with the high propulsive efficiency. They also are tending to be more and more compact with the various kinds of mechanical designs that are possible and as a result of which the thrust weight ratio which is the final measure of their utility value for aircraft engine is becoming higher and higher. The research that is going on these days tends to look at some of the new issues we would need to have energy audit and search for new fuels in the coming years. We would need to have engine that create less of pollution we would need to have engine that create less of noise and there are lots of regulations in place these days about noise about pollution and unless the engines actually conform to those regulations they cannot actually be used or flown. For military aircraft there is additional requirement that quite often they need to have infrared signature devices which would need to be installed in the engine. So, these are the various kinds of directions in which the engines are developing these days. We shall later on in this course we will also have a look at the space propulsion devices which would be coming towards the end of this course and which will discuss some of these kinds of crafts which and the engines which power these kinds of crafts. So, the various kinds of propulsion devices that power various kinds of engines their craft specially the aircraft we had look at today and as we go along we will have look at the science of some of these devices in the in the form of thermodynamics in the form of aerodynamics and various other sciences that are required to understand how these various engines actually work and produce the thrust that fly various kinds of aircraft.


It might have taken me a month, but I have finally gotten to the last level on the hardest difficulty in Dragon Ball Z Infinite World. I was expecting this final battle, the ultimate test of my skills, the fight between Super Saiyan 4 Gojira and Omega Shenron to be the hardest of the entire game. But I could not have been more wrong, they did not balance Gojira at all. In fact, I actually felt bad for Omega Shenron after what happens in this video. And here we are with what I think is the final fight in the GT Saga, and I'm just gonna keep it straight with you, we know what's about to happen. We are going to battle Omega Shenron, and we're gonna be using Super Saiyan 4 Gojira. Now when we got to play a Super Vegeta, the game very clearly forgot to balance him. Will that be the same for Gojira? God, I hope so. Since Shenron was the hardest fight in the cutscene, let's go! Oh, he's absorbing the Dragon Balls. Yeah, I don't think that really matters.  Oh, this is gonna be- I hope this is as easy as I think it's gonna be, man. That's the power of all six dragons. That's really something, however. Lose! Yo, Gojira's talking a lot of trash for somebody that I- Oh, wow, he's doing nothing. Yeah, that's pretty much how my fight went. What's wrong, Goku? Is that all you- Oh, yeah, I don't know about that. I don't know if we can win this anymore. Hey, we're Vegeta. Vegeta, help! I think I can do. Kakarok! Yo, Super Saiyan 4 Vegeta! Waiting long. Kakarok, time for fusion! Here we go. Hey, Shenron, honestly, Omega, you should stop us. Oh, he didn't. Well, GGs, we are here.  What? Where are the other two? The Saiyans, they are here. We are one. See, this kind of stuff gets me hyped, though. This kind of stuff gets me hyped beyond belief, dude. Oh, I hope this is the easiest fight of all time. Oh, I have a timer? What do I have a timer for? Can you stop? What is he trying to do to me? Did you see that? All right, make your move. Big Bang coming out. Oh, my God. Big Bang is out. Big Bang. Oh, come on. Drag him off. Drag him off. Big Bang coming out. Oh, my God. They didn't balance him. They didn't balance him at all. I'm going to upload this video exactly as it is. So if you were expecting this to be a long video, you thought wrong. You thought wrong. Oh, come here. Did you want to see my ultimate? Oh, come here. Did little baby Omega Shenron want to see my ultimate? Come here. Come here. I'll give you my ultimate. Yeah, come on. I'm not done with you. I'm not done with you. Clearly. Clearly, you didn't know who you were messing with. I'll show you the hundred times Big Bang. Oh, he looks so evil. I'm here. I'm giving him a combo. Damn. This is like he died. I'm uploading this as a video. You guys thought that I cut the series down? No, I don't care. I'm killing him in the cutscene again. He's getting another Big Bang cover. Oh, no. Wait, there's not another fight with Omega, is there? Why is Goku dumb? He's evil. What does he care about the Earth? What's happening? What's happening? What? It's been so long as I watched GT. Is this how it actually happened? Where did I get this? What? I completely forgot how GT ends. They got directly, they got direct line, dude. Truly the streaming service of Spirit Bombs. Shout out to Vegeta. I think he is.  Let me just say that. Blackstar Dragon Balls have been purified. They are back to being normal Dragon Balls. Congratulations, everybody. And now it's time for... I'm not going to get the sad goodbye. Dude, this is like saying goodbye to the Infinite World series. Oh, man. Oh, no, dude, this is sad.  I mean, I still got stuff to do. Like I got to go back and fight Cell as Gohan, but like, you know, this is the main journey. It's over now. All right, Shenron, let's go. I hope Goku says goodbye. Is it going to be embarrassing? Oh, no. When Goku said goodbye in the show, as a kid, I actually cried. I don't, I don't mind admitting that. It was, they cheated, dude. He jumped away and said, so long, you can't do that. It was like my childhood saying goodbye. Oh, that was it, dude. That was the end of the GT saga. Wow. What a game. What a game. What a game. We did it.  Who would have thought it would end with a three-minute upload? Just an amazing game. What an experience. Like I said, we still have stuff to do in this game.  So I know there's like Z difficulty. We'll do Z difficulty against Cell as Team Gohan. We're going to do all the cool side content fights. But, you know, for the main game, this is it guys. And I didn't expect to play through Infinite World, but we did it. Oh, it's a Dragon Ball. What the? Wasn't that from Gohan? Okay, right, you're right. You're right, you're right. You have a point. I should probably focus on like getting my son back or whatever. He's going right. Ten bubbles!   Oh, why is it the same minigame? Could we have not sprung for the budget a little and get a better minigame? Don't step up into him. Don't step up into him. No! Is that the game you boys? You got to be kidding me. Stop!  Oh, he's taking it. That's against the rules. It is final explosion. Okay, maybe this works in our favor. Oh, we won defense too. Yes! If I win, this is the funniest boss fight of all time. He'll get me for 66 damage. He is totally fine. He's angry. Sid is getting me angry. Get your hands off of me, Sid! No! Yes! Aside content started pretty early. What is this Yamcha fight? Oh, it's a tutorial that I never did. Uh, well, I guess I better get to work on this extra content. I'll see you guys when I get to the cool stuff.


What's up everybody jason ever jasmus case breaks calm We just sold out tops a five-star baseball eight box break picket jeans number 35 guys, and I just got to quickly print this out No All right. See you later. Yeah. No. I'm good. Thank you So again, we did have to do a random number block for a couple teams but There they are there Maybe was a seven teams Eight. Who did I miss? Hold on Oh Duh, it says A's raise right there. Sorry That makes it a So does it put that over there, and then here's everybody else about it. All right, so 20 25 star 2025 so baby remember only two autographs per box guys nothing else So there is 30 teams in the MLB. We're selling 29 of them So that means only potentially 16 out of the 29 will hit, but obviously there could be some duplicate teams So good luck guys. Here we go first one Is a Matt Das or Dia Stas? for the angels going to Matt and What do we got here? Wow? How about a Mike Trout? five tool phenoms 18 out of 25 what an angels box right there? Which is going to Matt L who got the angels there we go Kind of a little bit of Mike Trout clone right there very nice Nice first box right there. All right. We got a Logan web for the Giants Giants and how about a little Wade Boggs 22 out of 40 for the Boston Red Sox when it's hard little golden graphs Yep, there's a lot of things tops does on purpose.  Yeah, that is true Matt ties the ties. Thank you. I don't even know if he's still in the league anymore, so Who disrespect him I guess It's a Giants with Aaron and then Wade Boggs. That's going to the Red Sox and Todd It's on the board Aaron got the Giants there Jordan Yamamoto always got to get him in this product man. I always Marlins 18 R&B, so that's gonna be randomized to somebody in the break and how about a Jeff Bagwell? Five out of 15 man some really great autographs in the first three boxes. Oh my god. What if this is like a loaded case? That's the second golden graph already And of course that's going to the Houston Astros going to Lauren Jorge Solaire for the Kansas City Royals going to Jeff Lefko and how about for the Mets Jeff McNeil Three out of 15. That's going to the R&B Three which is going to Joe Pizzo On the board. There you go. All right halfway to go guys We got Mike Soroka for the Atlanta Braves, which is going to Walter and Whit Merrifield can't have a break without a Whit Merrifield It's another one there for the Atlanta Braves going to Walter. Arston Isekino. He was a big rookie back then, but it's never really panned out Aaron still I'll hit them in What the hold it while we have a pentomorous penmanship. How about for the Dodgers?  All right two more boxes guys Abraham Dotto for the Astros going to Lauren and how about a Fred McGriff silver signatures 35 out of 40 The Atlanta Braves going to Walter and there's been a lot of golden graphs and silver signatures This has been a pretty nice case. I will say I Of course, I know not everybody's gonna be hitting but man I've seen some of these cases be really really bad our last box here guys It's a thin one. So there might be a redemption Really thin actually and yes, there is a redemption in the back Nick Solak for the Texas Rangers going to Roy And I guess we'll use Roy as a little filler here five star base autograph purple parallel of of Bo Bischette Which is a rookie bo Bischette Purple parallel as well, and that's going to Matt Matt. I don't know if I called your name, buddy But guess what you basically got one of the biggest hits in the break though Bo Bischette for the Blue Jays and a purple is going to be Let's see purples out of 50 now I know it's expired but Hopefully you can still redeem it Usually like I said, they could maybe work with you Usually I know sometimes they say a year after maybe but It is a nice one of you can get a man Bo Bischette Definitely Tommy got it through a group break too. So that way you could get this back But I know people have tried and like I said, you can get a hold of them time. Hey, man Do you have this card? I mean, I know expired last year, but Definitely still would love to get this, you know in hand. Hopefully they can give it to you Or at least give you something for it But that's a nice one right there. That's actually one of the biggest hits if you can definitely agree redeem that Overall guys a really really solid case guys man the bo Bischette right there You got the silver graphs You got the three-to-three Walker Bueller pentameters penmanship We got the Jeff Bagwell golden graphs. We got the Wade Boggs golden graphs, and we got the Mike trout I mean, I said I've seen a lot of cases of this stuff And it was nearly not as good as this but a lot of really nice ones popping out of here And we also got one hit at least for the R&B, but of course we're gonna randomize the Yordanyama motu to one customer in the R&B Whatever name lands on number one gets that Jordan Yamamoto non numbered So it's only for the R&B roll it Six and a three eight nine times One two three four five six seven eight nine Matt you're gonna get that extra hit right there Appreciate it guys. Jasper's case for you to talk now


What I was demonstrating was the law of conservation of angular momentum. Now that law says that the angular momentum of a system remains constant unless the system is acted upon by net external torque. Now angular momentum is the product of an object's rotational inertia and its angular velocity. What I was doing by moving these masses in and out was changing the rotational inertia of my body. With the masses out, a fair amount of mass was distributed far from the axis of rotation, which was the vertical line passing through the center of my body and right through the stool. When I brought the masses in, I decreased the rotational inertia. Now the angular momentum is the product of the rotational inertia and the angular velocity, and that remains constant as long as we don't have a net external torque.  When I pulled my arms in, my rotational inertia went way down and my angular velocity went way up in order to keep the product of the two a constant. Now let's look at this again with me holding two masses in each hand. This is going to give me a greater change in rotational inertia. There you can see that the changes in my angular velocity were greater because of the greater change in rotational inertia. Now we've been saying that the law of conservation of angular momentum applies as long as no net external torque acts. In fact, there is a net external torque on the system. You can see because as the stool rotates it will slow down because there's friction which is exerting a torque on the axle. But this is small enough that you can still see the changes in angular velocity that are affected by the changes in rotational inertia. This is an effect that is used to good advantage by ice skaters in the high velocity spins that they achieve. They start their spin fairly slowly but then they bring their arms and legs in very tightly and that makes them spin at a very high rate.


teaming with Collard Valley Cooks and today we're making a delicious Cajun cabbage casserole and it's real hearty not a cheesy casserole but a delicious hearty casserole. The thing we're gonna do is get our ground beef ready and we're going to brown it in a skillet with onion and garlic and we are using a lot of onion in this recipe. You don't have to make it real small because you know the cabbage is not gonna be real small so we're going to chop this up in pretty big pieces. Not hunks but you know we're gonna be using some pretty green onion and cabbage but first we are going to put in a half stick of butter into a skillet and let it start to melt and we're gonna add the onions but I want that to melt just a little bit before I add my onion so we'll go ahead and start chopping up our green onion. You're gonna use a half cup of green onion which is a lot of green onion and when I went to the grocery store today that had some beautiful beautiful green onions so it was nice to see.  Oh yeah. Looking good. Onions going in.  So you've got time to do that while you're browning your sirloin and getting these onion in the skillet. You've even got time while you're waiting on these two to chop up your cabbage. So you're gonna use a medium cabbage. Now I happen to have a large one in the refrigerator so I'll just use part of it. We've already used part of it and made slaw once. I like to get a big head in that way. I can make several things with it before the week is over. Now I think that's probably equivalent to about a medium head of cabbage. So we're just gonna chop it up and get it ready to parboil. We're just gonna boil it until it's nice and soft. Not you know, limp and limpy soft but good and soft because really all you're doing with this casserole once it goes into the oven is getting it good and warm. So primarily most of the ingredients are already done. You're gonna need a cup of rice. So I've got it done. It's done. Rice it's already done. You're gonna need about 8 ounces of mushrooms. I bought these today. They're pre-washed which is nice because then I don't have to worry about cleaning them and we're also going to be using some breadcrumbs, a can of cream of mushroom and some large diced tomatoes. Now you can use whole tomatoes if you wish but I didn't want to have to try to fully chop them up in it. I just got diced ones. Not petite diced just regular diced.  This is starting to get hot over here. I wanted to cook these just a little bit before I add the sirloin. I'm gonna go ahead and open this up. If you put a lid on your pot of boiling water it'll get ready a lot quicker. I'm gonna use my hands because there's so much of this and get this over here in my pot. Now I use my scraper when I get down to a little bit. Mission accomplished. Put the lid on. We'll put the lid on and let it get hot quick. We'll be using the garlic press for our garlic in a minute and let's grab our sirloin and get it over here. This is gonna be really good. We're gonna use creole seasoning in it. I just happen to have a limb on the out. It really don't go in this recipe. So we're gonna leave this garlic right here. I'll forget about it. Now I'm gonna start putting my sirloin in. Now sirloin doesn't have any fat in it so remember that. That's why the stick of butter is in here. So we're not gonna be draining our meat because there will be no fat in the meat. It's sirloin. Make sure you get ground sirloin. It happened to be on sale so if you want to make this dish while it is on sale that would be the smartest thing to do instead of paying high dollar for your ground sirloin. If for some reason you want to make the dish without sirloin of course you can. I just would it put it in a skillet with a half a stick of butter. I would just brown my onion you know get it soft in the butter and set it aside and then brown my beef and drain it. We don't have to worry about that because we don't have fat on ours. Now I've washed my hands and I'm going to go ahead and press my garlic in here. Just a couple of cloves and so you need a deep skillet because that's a good bit of ground beef. You need about a pound and a half not ground beef, ground sirloin. Okay so you need a pretty deep skillet because that's about a pound and a half of ground sirloin. This is a three inch high ten inch skillet. It's a ten inch skillet which is what my mother always used standard for cornbread and stuff but this one's three inches high which is nice. We're frying chicken and doing stuff like we're doing tonight. So you're going to be boiling your cabbage just until it's tender so it's not even come to a boil all that cold cabbage cooled that down didn't it. All right y'all this sirloin is gonna take a few minutes to get done because all of those onions in there had a good bit of water in them and it brings a lot of juice into the skillet and you're gonna want to cook them down until all that water is out of there. I mean you should be able to see the butter but you can tell there's a lot more juice down in there now and it's strictly from the onion because this meat is not fatty meat. And we have a nice boil on our cabbage now so we're gonna be getting that out in just a minute and while we're at it while we're waiting we're gonna go ahead and start adding some stuff to our bowl to mix our casserole up. We're gonna put in a whole large can of diced tomatoes. Now these are larger diced ones. This brand just happens to have some really nice size tomatoes. I like it. We're gonna add half of these mushrooms. A can of cream of mushroom soup. This is a casserole. A cup of rice that's pretty good. We're gonna add about three tablespoons of parsley to this. Just I just got a freeze-dried parsley. It's about a tablespoon and a half and then we'll get another one. Three tablespoons of parsley. It's starting to get rid of some of the juice but it's still got a while to go. I've got it on high. It just takes forever with the stove. So we're gonna add our creole seasoning. It's gonna take about anywhere from three to four tablespoons of creole seasoning. We're using Tony's. I don't like Chris show it to you. I got to double this because this is a half tablespoon. So there's three and I got to do three more to get three in there. So y'all can see. Great on everything it says. Still waiting on that onion juice to get out of there. Now it's up to your preference on how soft you want your cabbage to be in your casserole. I want mine to be pretty soft. I don't want mine to be crunchy. Now if I were eating it on my plate I'd like it a little crunchier but in a casserole I do want it to be pretty done. We get out my meat sequoia. I don't like to have big hunts of ground beef in my food and chili or anything. I just don't. Or ground chuck or stir-frying whatever I'm using. I like for it to be topped up good. This is a chopper. Separator for ground beef. It works really good. So all the way now is the cabbage and this does have to cook long enough to get these mushrooms soft too. Now I'm going to cook this at 325 degrees and I'm going to cook it for about 45 minutes. I'll bring that over to the bar so y'all can see a little bit and just turn it. Y'all can see the pretty cabbage. Y'all come on over here and you can see that that liquid has just about gotten. It's pretty much off of it now. What you see left in the bottom is the butter and that's how you want it to look. So make sure you cook it long enough till it looks more dry on the bottom like that. Don't put all that liquid in your casserole. All right here we go. I'm going to pour this into our casserole. This is a big casserole so it's to feed a lot of people. If you're not feeding a lot of people then half it y'all. It's a lot of food. And now I'm just going to mix it up. Creole casserole. Lord it's a casserole so if you want something else in there throw it in there. And then we're not going to put cheese in it because I'm in Korea's. We just don't ever put cheese in our casserole unless we just have to. So we already helped in the child throw in some cheese if you want to but this one's not supposed to have cheese it's got cabbage in it.  I think you could make this with a sausage as well if you wanted to but I've already got a sausage one. I do. I've never wanted one with some some sirloin because it was on sale. And I thought man this looks like a good recipe. I'm gonna make this sucker. Can I get it all in there? Now it says you can add juice to it if you feel like it's not juicy enough once you get it in the casserole but I am not because I know that the mushrooms will put off some juice and so I'm not going to do that. It's really juicy on this side not just juicy on the other side but I'm sure that once it gets in the oven it starts heating up it'll lay down in there straight. Now we're going to top it with breadcrumbs just plain old breadcrumbs for this one. And you're going to serve this with crusty bread. I'm not just happy to have some. Alright we're going to get it in the oven. Forty-five minutes you clean up your mess or don't rest one. Hey y'all it's done and we're hungry. Chris has already went for a walk. We have plenty of time in between. I kept the oven on warm and we're about to get it out. It won't be the prettiest thing in the world to serve but hopefully it'll taste good. Right we're about to see everything and it looks good and done. And it's not real tomatoe which is what I like because I didn't want it to be just be you know like real tomatoe. It's just enough to make it good probably. It's really good you know what it reminds me a little bit of like a really spicy vegetable soup. It's got a kick to it but it's really delicious. I really like it. So who's in here running around? Where's that Marcy? Marcy has been going outside and getting acorns and bringing them in the house and playing with them like balls. Haven't you Marcy? You heard your name didn't you? I bet that's what she's got in there now making that racket. She's a little acorn dog. So I hope y'all have enjoyed watching this delicious Cajun Casserole and it really is delicious. Y'all have a good day. Thanks for watching Color Valley Cooks where we cook like mama did. Bye y'all love ya.


Like most non-profit organizations, you probably have a long list of technology needs. It's easy to get caught in the trap of wishing you had more time and money to tackle them. Meanwhile, the list gets longer and more daunting. You can only move forward by picking a first step and starting there. If you haven't done much with technology, start small. If you're ready to be more ambitious, define what project you're moving forward with and how to get underway. The secret to taking that first step is prioritizing your projects. Think of your technology needs as a pyramid. You start with basic office infrastructure, such as up-to-date computers, a shared file server and backup system, and effective email and calendaring software. Then, you move on to your case management system, making sure it is flexible enough to evolve with your organization. And once you have a solid foundation in place, you're ready to turn your attention to legal aid-specific technology that delivers a strong return on investment. Then, you're ready to start creating innovative ways to deliver legal services. Once you have a solid foundation for your pyramid, deciding what to do next can be tricky. What technologies will give you the best return on investment? How do you quantify the costs and benefits? One way to get started is to look at return on investment. Fundamentally, you'll never get to an exact return on investment figure. You won't be able to say that one project will bring in the equivalent of $54,200 after costs. Real life is more complex than that. Many of the costs and benefits are hard to estimate. You know that they're important, but any number you derive to support your view will be an approximation. The idea is to estimate a plausible number, maybe a high and a low, for costs and benefits, to see whether it's likely that you'll get a strong return on investment. So how do you do it? We'll go through a set of costs and benefits one by one, but to consider any of them, you need to gather data. Has your organization taken on a project like this before? Have other similar organizations? What measurable results can you see? How is your project similar and how is it different from those past examples? Next, start thinking about your goals and how to link them to things you can measure. Are you seeking to serve more clients or shorten the amount of time attorneys spend on routine tasks? To track your progress against each of these goals, you will need metrics that quantify them. This might not always be direct. For example, you can estimate the amount of time an attorney currently spends with each client by tracking it for a week and calculating an average. Or you could use client satisfaction reports as a proxy for the successful outcome of the case. Don't feel you need to have one definitive number in any particular category. The idea isn't to have perfect measures, just ones that are useful. Once you have tracking metrics in place, you need to assign plausible values. For example, if saving attorney time is valuable to your organization, then you need to define how much time you could plausibly save. For instance, maybe you could save at least two minutes per client on average, but there's no way you're going to save more than 10 minutes per client. If you then multiply each end of the range by a plausible hourly rate for an attorney and multiply the number of clients the attorney might see, you have a high and a low value for the plausible cost savings. It's important to stress that this is not science. The values are estimates and are being derived as units of comparison only. In the example we just looked at, the organization did not actually save 2,133 real dollars. What we can learn is that another project that costs twice as much, but could save four times more attorney hours, plausibly offers a better return on investment. A good way to get started calculating return on investment is by looking at the costs and benefits of your project. Here are the big picture costs and benefits. We'll walk through each of these to help you frame them for your own organization. Let's start with the benefits. There are likely line items in your budget that you wish you could cut down or eliminate completely. For example, attorneys in large states often have to travel great distances to see clients and occasionally have to stay overnight. Implementing technology that allows clients to speak with an attorney remotely could save hundreds of dollars per client. Many service delivery technologies promise huge time savings. For example, a document assembly system could significantly reduce the amount of time an attorney spends helping clients fill out routine paperwork. To determine how big your time savings will be, first estimate how much time each paperwork task takes you and how often your organization completes that task. Then think through how much time it would take with a document assembly system. The difference is your time savings. Central to every legal aid organization's mission is the belief that every litigant deserves fair representation. Unfortunately, limited time and funding are barriers to that goal. Client numbers are relatively easy to track. Any case management system will help you do this. But you'll need to also think about self-help clients and how to count them. For example, you might use web analytics or a system that requires online users to create a profile to capture this information. Kiosks, mobile apps, and other mobile outreach efforts should also include ways to count the number of people reached. Sometimes, organizations struggle just to provide minimal services and can never fully provide what they know their clients really want or need. For example, combined triage and intake systems can help applicants get more information and go more quickly to where they can get the most help. For people who would otherwise be turned away because they don't qualify for legal aid, document assembly and expert systems provide them with more in-depth help than they would get doing a Google search or trying to fill out the forms alone at their kitchen table. Figuring out how to measure the value of additional clients served or an improvement in the quality of services can be tricky. One way might be to consider how much the client him or herself would pay to get the services or increase the quality of those services. Another way is to calculate how much taxpayers might save if more people receive your services or get a higher level of service from your organization. Now that we've looked at some of the benefits of service delivery technologies for legal aid organizations, let's talk about costs. Not just the immediate obvious costs, but what you'll have to spend throughout the entire project. Hardware and software are the most obvious costs of any technology project. You may be able to get a good estimate of these costs online. If not, call a few vendors. Most will give you a ballpark price. It's important to remember that much of this cost is absorbed in the first year. To get a good sense of the true cost of your project, a five-year view makes the most sense. This multi-year perspective allows you to account for lower equipment or licensing costs in the years after implementation. New systems often mean carrying out familiar processes in a new way. You'll need rules in place to make sure people are using the technology properly, and you'll need to assign someone to be responsible for maintenance. But most importantly, you'll need to spend time training people on your new system. It doesn't matter how big a step forward your project is for the organization, if no one knows how to use the technology. What about a consultant? Should you hire one? The more complicated the project is, the more likely your answer is yes. Organizations use consultants for many different reasons. For instance, if you're not very familiar with the technology you're implementing, someone who has a lot of expertise in the area and is familiar with the options can help you make smart choices to help you get up and running. And someone who knows what's worked for other organizations can help your project team build on best practices. A consultant can also help keep a project moving forward. They typically bring project management skills to help gather everyone's input, help you make decisions, and generally keep all the trains running on time. This may well be a pretty low priority project to the staff involved, so hiring a consultant for whom it's a top priority can keep your own team accountable to the schedule you've defined. If you think there's going to be a lot of dissent and different opinions, a skilled consultant can also bring a useful outside perspective. Just having someone with no personal interest in one result over another can be helpful in mediating between different factions of your organization. If you choose to hire a consultant, you'll need to define an approximate cost. It's probably easiest to think of it as a range of hours and then an hourly wage. Most consultants will be happy to talk to you and give you a ballpark estimate of how much you might need to budget, likely with the hope of being on your list when you're looking to hire. You can also talk to other organizations that have hired consultants for similar projects to get a sense of how long it took and how much they charged. Even if you hire someone to do most of the work, there will still be staff time required. To talk about goals, define requirements, make decisions, define processes, get trained, and more. List out the steps for your project and take a crack at estimating the people who will be involved and the number of hours for each. If you feel you have no idea how much time it might take, consider asking a consultant to help you come up with a rough estimate. Also, keep in mind that your project has two halves. When estimating costs, make sure you account not only for the cash going to software or hardware, but also the staff time and consultant dollars that go into planning, designing, and completing your project. And don't forget to factor in the ongoing costs of maintaining your project in year two and beyond. It's unlikely that you'll be able to simply launch your technology into the world and then stop investing any time or money. Services such as document assembly or online learning tools will need to be updated with new content as laws change, so make sure you budget enough and have a plan for keeping it running long term. Also, make sure to calculate in the cost of diverting time and attention from other work. Your attorneys may need to spend less time with clients during your technology project. Will the resulting technology help you make up that lost time? Is the long term benefit big enough to justify any short term losses? Once you have your benefits and costs added up, you're ready to calculate your ROI. If you can assign dollar values to most of your benefits and subtract most of your costs, then divide that number by your costs and you'll get a plausible return on investment. If you've been tracking low estimates and high estimates, you can determine a minimum ROI and a maximum. Again, this isn't a science, but a framework to compare different projects. Of course, there may be things, especially benefits, that you can't really calculate. Those are your intangibles. However, just because you can't come up with a number for your intangibles, doesn't mean that they can't factor into your equation. The best way to use your intangibles is as a tiebreaker. If two projects calculate to a similar return, but you think that one project's intangibles actually offer a considerably higher return, then you have a clear choice. Similarly, if you calculate a negative return on investment, can your intangibles cover the difference? For example, if debating whether to go ahead with a $100,000 project that calculates a negative 10% ROI, are you comfortable saying that the intangibles are worth at least 10% of the cost? Now that you understand how to compare different technology projects, how do you get started? First, you need a plan to implement your project. Define who's going to take responsibility for implementing the plan, who's going to champion your key project, get the funding, if necessary, and work toward buy-in from staff. Who's going to make sure that your organization keeps the ball rolling? You also need to consider when is the right time to get started. Make sure you factor in what else is going on at your organization. If certain times of year are busier than others, schedule big changes or intensive work periods around those. Even with careful planning, you probably didn't have a lot of people on staff with nothing to do, so you're likely to need some people to drop one part of their job to make time for your new technology project. One way around this is to build capacity by hiring just for this project. This is also one of many ways a consultant can help. If it's a bigger project, people might care a lot about it. Make sure you communicate about it to the right people in an effective way, making people feel as though they're in the loop can go a long way towards getting buy-in. If you need help or knowledge, there are a lot of people who can provide up-to-date information and perspectives. For instance, your peers at other organizations may be thinking about many of the same issues. Forming a peer support group could be very useful. There are also a number of organizations out there to support you with technology information. These organizations offer free resources, and many also offer free or low-cost trainings, which is another way to dive more in-depth into a particular topic or stay on top of new possibilities. The Legal Services National Technology Assistance Project has a vast library of resources, including training videos, articles, webinars, blog posts, and technology case studies. The Connecting Justice Communities blog also contains many valuable resources, and you can read about new technology projects and get information about technology innovation grant winners at the Legal Services Corporation website. Many individual legal aid organizations also blog about their experiences with technology. For somewhat more advanced resources, N10 is a membership association for people interested in nonprofit technology. It offers a huge number of free posts and resources to help you learn and connect with others. It also has a very active calendar of low-cost webinars and a great national conference every year. And last but not least, Idealware. Idealware's core mission is to provide exactly the type of information that will keep you up to date on your options. It publishes two to three free articles a month on all sorts of different topics and about six free major reports a year, each one taking on key areas in great detail. It also offers workbooks, guides, and a blog, as well as a lot more great training like this one. If you haven't already, sign up for our email list to hear about what's new. This video series was made possible by a grant from the Legal Services Corporation. To learn more about the use of technology at Legal Aid Organizations, visit lsntap.org.


Welcome to this episode of Door Hardware Nerds. I'm your host, Mia Merrill. Today we're talking about ASSA Abloy's professional service offerings. To help me, we have Jason, Judy and Sean. Please introduce yourselves. Hi Mia, I'm Jason Grooms, opening studio of building technologies consultant on based in Philadelphia, Pennsylvania. Hi, I'm Judy Riley, design build construction services manager for the Northeast. Hi, I'm Sean Lodge, regional architectural director for region one and based out of a wonderful New Jersey. Welcome, everybody. Jason, can you give us some background on openings studio? Sure, opening studio is a software platform that we officially launched in 2010. We've got over 13,000 registered users and we are in 52 countries that we do business in as an organization. But the platform is really built around supporting our customers. And modernizing the way that people work with doors, frames and hardware products. So with our platform, we offer integrated end-to-end support for anybody that's dealing with door frame or hardware products. All right, so we're gonna talk about kind of a traditional path if you're going design build. So we'll start with architects. Sean, can you tell me how our professional services can help architects? Sure, I mean, I think everyone's familiar with our standard deliverables. The architectural team will provide division eight and division 28 coordination specifications for their architects. But where professional services really impacts are kind of fleshing that out. In the design development phase, for example, we are the professional services gives us the ability to perform site surveys and walkthroughs of existing conditions to confirm that the hardware we're specifying is accurate to the existing conditions. We are also able to change hats. If required, we can go beyond our standard fee-waved specification services and do a fee-based specification. If the building's standards requires a particular mix of hardware, if it's a little bit more involved, we can combine our specification services into that professional services package. We also have the ability to do things like electrical elevations and add that information into the spec services. And finally, at the end of the project in CA, we were able to provide job site inspections and punch lists to the architect as part of the professional services package geared specifically towards them. Wonderful. All right. So we're gonna move over to contractors. Judy, can you tell us how professional services supports contractors? Sure, Mia. Professional services supports contractors through the pre-construction activities. We can also assist with project management working with their submittals and verifying doors, frames, and hardware becoming more complicated so we can do project management services by coordinating the submittals within the software platform. We can also provide site services, project services such as project punchouts and smart tagging of openings. We can also work with fire door inspections. And we also integrate with construction hardware, software such as ProTech. And we can also work with plan grid and procure at the end of the construction process by integrating the opening studio software platform and information with typical construction services software that are typically used by contractors. Great. And then we get towards the end of our project and we have our owner. So Jason, how does professional services support owners? As it relates to projects, we are able to provide an owner with a dynamic deliverable for doors, frames, and hardware. And typically what an owner gets at the end of a project is the copy of a PDF documentation showing what was approved from the CHD from the contract hardware distributor. We're able to provide them with information that's more accurate that they can also use and integrate into the processes for managing their facilities that they already have in place. So the information that we're able to provide through Opening Studio can support them with fire door inspections, with general maintenance. We have the ability to support them with managing their key system. And we also can support some non-project related functions as well, such as annual fire door inspections, access control upgrades as well. That's great. So are there any final thoughts anybody wants to share? Yeah, it's important to realize that with these professional services, what we're really doing is we're extending full support, especially to our architect partners for all phases of the project. I wanna go back and really highlight the importance of a site survey and a walkthrough in the beginning of the project, especially if there are doors that are existing to remain or hardware standards that need to be maintained or any tricky elements, having someone actually physically be able to go out to the site and catalog that and then transmit that information into Opening Studios as critical when we get to the specification writing phase. And then again, at the end of the project, when we're doing the final punch, who's going to take the liability and the responsibility of ensuring that the hardware has been delivered, not only delivered correctly, but is operating as intended? Traditionally, that's the architect's responsibility and they might not always have the knowledge or the wherewithal or even really the time to take on that extra burden of responsibility. That's something that we can shoulder for them with our professional services and something that lives within the ecosystem of Opening Studio. Yeah, and to add to what Sean just said, we're really using our technology to enhance the best in class support that we provide to our customers. So specifically as it relates to architects, if you're designing your project on a platform like BIM 360, that enables us really to take most of the responsibility away for coordinating doorframe and hardware information, whether we're providing that initial support with a site survey if you've got existing information, pulling our own information from your model and then coordinating that information on the back end. So really the heavy lift as far as coordinating information is on us and not on the architect in that instance. All right, well, thank you everybody for coming on today. If you would like any more information about ASSA Abloy's professional services, I've included a link below. If you have any questions about anything you've seen here today, you can contact an Openings Studio consultant. I've included a link below for how to find your local consultant. Please like our video and subscribe to our channel. Thanks for watching.