Poiseuilles law remains valid as long as the fl uid fl ow

Chapter , Problem 77

(choose chapter or problem)

Poiseuilles law remains valid as long as the fl uid fl ow is laminar. For suffi ciently high speed, however, the fl ow becomes turbulent, even if the fl uid is moving through a smooth pipe with no restrictions. It is found experimentally that the fl ow is laminar as long as the Reynolds number Re is less than about 2000: Re 5 2vrR/h. Here v, r, and h are, respectively, the average speed, density, and viscosity of the fl uid, and R is the radius of the pipe. Calculate the highest average speed that blood (r 5 1060 kg/m3 , h 5 4.0 3 1023 Pa ? s) could have and still remain in laminar fl ow when it fl ows through the aorta (R 5 8.0 31023 m).