Question

What is a suitable flow model for a fluid?

(a) Finite control volume approach

(b) Infinitesimal fluid element approach

(c) Molecular approach

(d) All the three models can be used based on the need

I have been asked this question in examination.

Question is from Infinitesimal Fluid Element topic in portion Aerodynamics – Fundamental Principles and Equations of Aerodynamics

Answer 1

Right choice is (d) All the three models can be used based on the need

The explanation: The finite control volume considers a finite volume which may be either fixed in space or moving along a fluid. The infinitesimal small element considers a finite element which may be either fixed or moving along with the flow. The molecular approach is a microscopic approach and can be applied to atoms and molecules.