Question

Someone claims that the average velocity in a circular pipe in fully developed laminar flow can be determined by simply measuring the velocity at R/2 (midway between the wall surface and the centerline). Do you agree? Explain.

Answer 1

No, I disagree

Step-by-step explanation:

The average velocity in a circular pipe in fully developed laminar flow cannot be defined by simply measuring the velocity at R/2 (midway between the wall surface and the centerline). Vmax/2 is the mean velocity, but the velocity at midway between the wall surface and the centerline is

`V(R/2)= V_(max)(1-(r^2)/(R^2) )_(r= R/2 )=(3V_(max))/(4)`

Where R represent the circular pipe radius and r is a local radial distance measured from center of the pipe to any desired point