In deriving Bernoulli’s equation, we equated the work done on the fluid in the tube to its change in the potential and kinetic energy. (a) What is the largest average velocity of blood flow in an artery of diameter 2 × 10–3 m if the flow must remain laminar? (b) Do the dissipative forces become more important as the fluid velocity increases?
(a) Diameter, D=2×10−3m Viscosity of the blood η=2.084×103Pa Density of the blood ρ=1.06×103kgm−3 Maximum value of Reynolds number of flow to be laminar, NR=2000 Average velocity Vc=ρDNRη =1.06×103×2×1032000×2.084×103 =2.124.168=1.96 m/s (b) The dissipative forces become more important with increasing flow velocity, because of turbulence.
