p0 1[Pa] Incident pressure tauP 1 Tortuosity Rfilter 150[mm] Filter radius Rtube 50[mm] Inlet/outlet tube radius Lfilter 200[mm] Porous filter length Lair 50[mm] Length of air part in filter Ltube 100[mm] Inlet/outlet tube length dh 5[mm] Air channel width ht 3.2[mm] Porous wall thickness