Question

Which of the following statements are correct for an incompressible flow?

I) In incompressible flows, variation in density is negligible.

II) Incompressible flows are always laminar.

III) Incompressible flows can be internal as well as external.

1. only I and II
2. I, II and III
3. Only II and III
4. only I and III

Answer 1

Correct Answer - Option 4 : only I and III

Explanation:

Incompressible flow: It is that type of flow in which the density is constant for the fluid flow. Liquids are generally incompressible while gases are compressible.

Mathematically, ρ = Constant.

These can be laminar or turbulent, external or internal.

Compressible flow: The flow in which the density of the fluid changes from point to point or the density is not constant for the fluid

Mathematically, for compressible flow ρ ≠ Constant