While not an ideal descri
While not an ideal description, this equation is considered a good approximation of the movement of blood through vessels.  This equation indicates a high dependency on the radius of the tube involved since it utilizes a proportionality that raises the radius to the fourth power.  It surpasses the Bernoulli equation in terms of realistic descriptions because it takes into account a fluid's viscosity and pressure, though it does not hold true for non-laminar flow.  FTP, identify this equation of fluid mechanics named after a French physicist and used to calculate a fluid's volume flow rate.
While not an ideal description, this equation is considered a good approximation of the movement of blood through vessels.  
Poiseuille's equation