For a small body moving in an otherwise quiescent fluid, the inclination of the boundary between the zones of silence and action is the arcsine of one over this property of the flow.
For a small body moving in an otherwise quiescent fluid, the inclination of the boundary between the zones of silence and action is the arcsine of one over this property of the flow. This parameter arises in the boundary layer equation from the natural scaling of the dependent variable and a necessary condition for potential flow is that this parameter be much smaller than unity. Since this dimensionless parameter is the ratio of the effects of inertial and elastic forces, flows are incompressible when it is small. FTP, identify the dimensionless number that is the ratio of the speed of an object in a fluid medium to the speed of sound in that medium.
For a small body moving in an otherwise quiescent fluid, the inclination of the boundary between the zones of silence and action is the arcsine of one over this property of the flow.
Mach number