Question

Ratio of duct length to width length in a compressible flow is_______

(a) More than 5

(b) Less than 5

(c) More than or equal to 5

(d) Less than or equal to 5

I have been asked this question during an online exam.

Question is taken from Flow of Compressible Fluid through Orifices and Nozzles in section Compressible Flow of Fluid Mechanics

Answer 1

Correct answer is (d) Less than or equal to 5

The best explanation: In a compressible flow, the flow is usually in a single dimension. One dimensional flow refers to the flow of gas through a duct or channel in which the flow parameters are assumed to change significantly. Thus, it is less than or equal to 5.