Hi Dear Foamers!!
I've found some strange behaviors of OpenFoam simulation. I'm now very confused. Is OpenFoam really reliable?
When I run the tutorial case "Wedge15M5"in the rhoCentralFoam, the result of pressure, temperature and velocity seems very satisfactory. You can look details in the master thesis dissertation "Simulation and validation of compressible flow in nozzle geometries and validation of OpenFOAM® for this application" by Benjamin Wuthrich. But these results are only static parameters. We must check the total (stagnation) parameters.
According to the normal shock wave and oblique shock wave theory, the stagnation pressure must drop after shock. But OpenFoam gives the fault result. You can see them in the attachments. I made no modification to the tutorial. So the result should be reliable. As shown in the attachment, stagnation pressure rises rapidly after shock. Even there are slight total temperature rises.
T*=T+U^2/(2*Cp);

So Dear Foamers, if I made mistake, please tell me what should I do. I would like to hear your advices or discussions or any suggestion. Please!! I think that it is important for all of the foamers.

PS: I can't calculate the total pressure and temperature according to compressible equation due to very high value of lambda (velocity/critical speed).
P/P*=(1-(k-1)/(k+1)*lambda^2)^(k/k-1) ----------- k= gamma = 1.4
U can also check other solvers like rhopSonicFoam, rhoSonicFoam



REF: Normal Shock Wave by NASA
" For compressible flows with little or small flow turning, the flow process is reversible and the entropy is constant. The change in flow properties are then given by the isentropic relations (isentropic means "constant entropy"). But when an object moves faster than the speed of sound, and there is an abrupt decrease in the flow area, the flow process is irreversible and the entropy increases. Shock waves are generated which are very small regions in the gas where the gas properties change by a large amount. Across a shock wave, the static pressure, temperature, and gas density increases almost instantaneously. Because a shock wave does no work, and there is no heat addition, the total enthalpy and the total temperature are constant. But because the flow is non-isentropic, the total pressure downstream of the shock is always less than the total pressure upstream of the shock; there is a loss of total pressure associated with a shock wave. The ratio of the total pressure is shown on the slide. Because total pressure changes across the shock, we can not use the usual (incompressible) form of Bernoulli's equation across the shock. The Mach number and speed of the flow also decrease across a shock wave. "