Kathrin 
June 3, 2012 09:37 
Machnumberindependence Oswatitsch
Hello,
for my studies, I've to develop a solution method for the machnumberindependence principle which is valid for very high machnumbers. In my case I assume
 ideal gas,
 inviscid flow,
 flow over a blunt body,
 2D flow,
 steady flow (at the end of the iteration),
 shock fitting.
In nondimensional form the systems consists of Crocco's theorem (a combination of the momentum equation and the first and second law of thermodynamics) with two equations for
and the gas dynamic equation which is a combination of the momentum and the coninuity equation and yields for
with entropy , xcomponent of velocity , ycomponent of velocity , density and with its spatial and and time derivatives . I complement the sytems with the equation of state and the entropy equation which can be calculated in a seperate way.
I know that the system is elliptic and hyperbolic in space depending on the local velocity. So a timedependent method must be applied. I already used MacCormack (without artificial viscosity) for a very simple case which was a 1D streamline but the system didn't converged and became unstable. :(
Can anybody help me to find the mistake or has anybody even already implemented these equations??? :confused:
