Boundary conditions for reflecting wall and hole
 

Hello Foamers,

I work with OpenFOAM now for about 2 weeks and am still unassure how to implement walls that reflect pressure waves and other walls that are like holes.

Can someone tell me what to set as boundary condition for p, T and U to have a wall that reflects pressure waves? And what conditions to set for walls where pressure passes through as through atmosphere?

Greets