Question

Which among the following is an assumption of Hagen-Poiseuille equation?

(a) Fluid is compressible

(b) Fluid is uniform

(c) Fluid is laminar

(d) Fluid is turbulent

The question was posed to me in class test.

Query is from Shear Stress and Pressure Gradient in division Viscous Flow & Turbulent Flow of Fluid Mechanics

Answer 1

Correct answer is (c) Fluid is laminar

The explanation is: Fluid flow is laminar as it is assumed to be incompressible and Newtonian. The flow is laminar through the pipe of constant cross section. Thus, there is no acceleration of fluid in the pipe. Therefore, Hagen-Poiseuille assumed that fluid flow is laminar.