Question

For which of these conditions was Newtonian law devised?

(a) Force on a flat plate in hypersonic flow

(b) Force on inclined plane in moving fluid

(c) Force on curved airfoil in moving fluid

(d) Force on flat plate in subsonic flow

This question was posed to me in an online interview.

The query is from Newtonian Theory in division Numerical Techniques for Nonlinear Supersonic Flow, Elements of Hypersonic Flow, Couette and Poiseuille Flow of Aerodynamics

Answer 1

The correct option is (b) Force on inclined plane in moving fluid

Easy explanation: Isaac Newton worked on a fluid – dynamics theory which would address the force on an inclined plane in a moving fluid applicable to low – speed flow which was later applied to hypersonic flow. According to the law, the force varies as square of sine of the deflection angle.