Question

This created a problem in modelling supersonic blunt nose.

(a) Change of flow equations from elliptic to hyperbolic

(b) High speed with high temperature

(c) Supersonic Mach number

(d) High temperatures

I had been asked this question in class test.

Origin of the question is Applications in chapter Philosophy of Computational Fluid Dynamics of Computational Fluid Dynamics

Answer 1

Correct option is (a) Change of flow equations from elliptic to hyperbolic

The explanation is: Straight to the nose of the vehicle, the shock is normal. This results in a subsonic region and elliptic flow equations. But, downstream the shock is oblique which creates a supersonic region resulting in the elliptic equation. This was the problem in modelling supersonic blunt nose. In later years this was overcome by a better model.