Question

What is the differential form of energy equation for quasi one – dimensional flow?

(a) dh – u^2du = 0

(b) dh – udu = 0

(c) dh + u^2du = 0

(d) dh + udu = 0

I got this question in an interview.

I need to ask this question from Governing Equations topic in chapter Quasi-One-Dimensional Flow of Aerodynamics

Answer 1

The correct option is (d) dh + udu = 0

Best explanation: The energy equation for quasi one – dimensional flow is given by:

h + \(\frac {u^2}{2}\) = constant

On differentiating the above equation we arrive at the differential energy equation for the quasi one – dimensional flow:

dh + udu = 0