Question

Which of the following flows have the highest critical Reynolds number (lower)?

(a) Flow in a pipe

(b) Flow between parallel plates

(c) Flow in an open channel

(d) Flow around spherical body

I had been asked this question in quiz.

I'd like to ask this question from Flow of Viscous Fluid Through Circular Pipes in chapter Viscous Flow & Turbulent Flow of Fluid Mechanics

Answer 1

Correct answer is (a) Flow in a pipe

Best explanation: The approximate lower critical Reynolds number for Flow in a pipe, flow between parallel plates, flow in an open channel and flow around the spherical body are 2000, 1000, 500 and 1 respectively. Hence, the maximum is for internal pipe flow.