CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   NACA 0012 mach 0.5 6 degrees (http://www.cfd-online.com/Forums/main/82894-naca-0012-mach-0-5-6-degrees.html)

papis December 8, 2010 13:30

NACA 0012 mach 0.5 6 degrees
 
HI,

I have a code that solves the viscous/inviscid cases.I am working on the validation of the code and i have seen a shock wave appearing at mach 0.5 at 6 degrees(inviscid case) but only in fine grids.The strange thing is that in coarse grids as well as in viscous cases the shock isn't there(cl ~0.75 in coarse grid ~0.669 in viscous cases).However when i use a fine grid to run the inviscid code a shock appears and the lift coefficient is around 0.85...

I know it's weird and i am looking for a bug for a while now but nothing came up.Has anyone here experienced anything like this?

papis December 9, 2010 12:27

It would help me much if somebody was able to run an inviscid naca0012 on a fine grid at mach 0.5 at a = 6 degrees and post the pressure coefficient.

Thanks again.

ignat December 10, 2010 03:38

Quote:

Originally Posted by papis (Post 286570)
The strange thing is ...

This thing is not strange because all difference schemes have non-physical (artificial) viscosity depending on grid spacing. Your shock is weak and it smeared at coarse grid. It is natural phenomenon.


All times are GMT -4. The time now is 23:20.