[maxims]

Boundary conditions:
See the following resonator figure, all the pipe walls are set as non-slip and isothermal. A static pressure oscillation at the left side of this pipe is known as p(t).


Question:
How can I deal with the boundary condition for the left side of this pipe in my code? It seems like inflow boundary, but also like outflow boundary, because this left side is the only contact interface with outside air. The only boundary condition I know is the static pressure history p(t), the velocity condition is unknown. Any suggestion is welcome.