Question

If compressibility force and surface tension force are neglected from the Newton’s second law of motion, which of the following equations result?

(a) Navier-Stokes equation

(b) Euler’s equation

(c) Bernoulli’s equation

(d) Reynolds equation

I have been asked this question by my college professor while I was bunking the class.

This intriguing question comes from Introduction to Fluid Dynamics in section Fluid Dynamics of Fluid Mechanics

Answer 1

The correct choice is (d) Reynolds equation

The explanation: The Newton’s second law of motion comprises of 6 forces, namely, gravity, viscosity, pressure, turbulence, surface tension and compressibility forces. Reynolds equation comprises of 4 forces. Surface tension force and compressibility forces are neglected for finding Reynolds equation.