Question

The fluid flow in Newtonian theory is modelled as which of the following?

(a) Stream of particles in rectilinear motion

(b) Wave

(c) Stream of particles in conic section

(d) Particles moving in a random direction

The question was asked during an online interview.

Question is from Newtonian Theory in portion Numerical Techniques for Nonlinear Supersonic Flow, Elements of Hypersonic Flow, Couette and Poiseuille Flow of Aerodynamics

Answer 1

Right answer is (a) Stream of particles in rectilinear motion

Easy explanation: Newton formulated the Newtonian theory by modeling the fluid flow as a stream of particles that move in a rectilinear motion. The individual particles of the flow stream do not move in a random direction. The particles lose the momentum normal to the surface once it strikes. Its tangential momentum is retained without any loss.