[Ferdinand5356]

Hello,

I am working on a simulation of a reentry burn of a rocket. I would be very grateful if you could help me on these following points:

The main problem I have is to assign two different fluids: air for the free stream conditions and exhaust gaz for the rocket's engines MARKER. Is creating two zones a better option or could I (and in that case how), simply apply a boundary condition to the MARKER engine with specification like gaz composition (H20 88%, OH 7%, H 5%), vapor state, and specific Mach number, temperature and pressure. I did simulation with MARKER_SUPERSONIC_INLET= (Engines, 1580, 60000, 2988,0,0) which works but it's air. Is there any other fluid that could approximate at least if I can't have these precise spec.

I tried creating two zones but the simulation diverges directly when running first independently each zone, I think because a bad mesh quality. Could I maybe create two zones and for the second zone (the engine one) just define a boundary on which I can apply the desired conditions.

Also, for supersonic flows, which of REYNOLDS or TD_CONDITIONS is more appropriate ? % for initializing the solution (REYNOLDS, TD_CONDITIONS).

I am not sure how to choose an appropriate CFL number for the simulation. Should I use adaptative CFL ?

I put REYNOLDS_LENGTH= 1.00 which looks strange to me as the rocket has much bigger dimension but when I try to put the REYNOLDS_LENGTH=diameter, the simulation won't work REYNOLDS_LENGTH= 5.00 . Could you advise me on this please.

You can find attached the file: testcfg, which works but is too simplified because of the engine BC problem, so that you can get an idea.

A big big thank for your help, really appreciate it!

Ferdinand

[bigfootedrockmidget]

Hi,
For this, the NEMO solver is most appropriate. You need to compile SU2 with the additional meson option

-Denable-mpp

It uses the mutation++ chemistry library. You can use your own composition then.

When you compiled SU2 with mutation support, you can first try the nonequilibrium testcases in the repository to see if everything works as expected.