extrapolation BC
 

Dear community, In my model I have a mesh around a rocket and the mesh is cut at the end of the rocket which is an extrapolation BC, and the way to implement it in Fluent is using outflow BC. However I cannot use it for compressible flows. Does anybody have an idea of what to do? I suppose pressure outlet would be wrong. PS: Expanding the mesh and using pressure far field is a solution for sure but I dont want to change the mesh. Regards emre

Re: extrapolation BC
 

Hi

I don't work with compressible flows, however, most of the works that I have seen with compressible flow use as boundary condition velocity inlet in conjunction with pressure outlet.

Regards

Alex Munoz

Re: extrapolation BC
 

Hi, Mass flow inlet and pressure outlet works very well for comressible flows. However pressure outlet is not suitable for this case, since pressure cannot be fixed at extrapolation BC. I suppose I found a way to simulate extrapolation BC. That is non-reflecting boundary conditions NRBC(which you can activate using text user interface). Yet, it only works with hexa cells and coupled explicit solver. So my problem is still not solved. Regards

emre