Mach contour expansion wave wrong
 

Hello,


I am simulating the hypersonic flow around a 2d wedge at M=8. So far the solution converges but it seems as if Fluent doen't display/calculate the expansion wave at the end of the wedge correctly. What I expect is a rise of the Mach number behind the expansion wave, this doesn't happen, at least that's my interpretation of the contour plot. Maybe this is due to the influence of the for high Mach numbers typical wake space behind the geometry?



I have heard that Ansys CFX can have problems regarding this topic but I haven't heard anything similar for Ansys Fluent.



Has somebody experience on this and/or can give me a hint where the source of my problem may be?


Thank you very much!

Mach Contour
 

Do you have any comparable work from the literature? The contours don't look at they should; not just at the wake but even upstream. Do you have fine enough mesh? Which numerical schemes have you used? And are you modeling it as inviscid or viscous flow?

Hi vinerm,
thanks for your reply.

I have to mention that this is a wedge with a small radius at the tip.

Fluent Settings:
Density based
implicit
Roe-FDS
2. Order Upwind
Geen Gauß node based
viscous flow, k-w-sst

I have around 300000 cells and I have refined the mesh near the geometry. I also implemented a y+<1.
I have comparable simulation data for sharp wedges only.
That's interesting, I thought that at least everything upstream to the expansion wave was correct.

Does this information help you on judging this case?

Thanks

Does somebody else have an opinion/idea for solving this problem?


Thank you very much.

The result should be something like this, right?(but without reflecting surface):


https://ars.els-cdn.com/content/imag...30336X-gr1.jpg


Source of the image:


https://www.sciencedirect.com/scienc...0093611930336X





Have you changed the legend? e.g. between 3-6 Mach ?


What about the schlieren image?