Ztrans (intop_in(ta.p_t)-intop_out(ta.p_t))/intop_mid(w)/(rho0*c0) "Transfer impedance (COMSOL, normalized)"
Zn (intop_in(ta.p_t)/intop_in(ta.u_tz))/(c0*rho0) "Surface normal impedance (normalized)"
R ta.port1.P_out/ta.port1.P_in "Reflection coefficient"
alpha 1-abs(R)^2 "Absorption coefficient"
ks sqrt(-ta.rho0*ta.iomega/ta.mu) "Shear wave number (viscous)"
Z1 ta.iomega/(c0*sigma*(1-2/(ks*a)*besselj(1,ks*a)/besselj(0,ks*a))) "Cylinder impedance expression (linear contribution)"
EC 16*a/(3*pi)*(1-1.4092*sigma^(1/2)+0.33818*sigma^(3/2)+0.06793*sigma^(5/2)-0.02287*sigma^(6/2)+0.03015*sigma^(7/2)-0.01641*sigma^(8/2)) "End correction and hole-hole interaction (Fok function)"
Cd 0.76 "Discharge coefficient"
U intop_mid(w)/intop_mid(1) "Average velocity in orifice"
Z2 (1.2*(1-sigma^2))/(2*c0*(sigma*Cd)^2)*sqrt(0.5*U*conj(U)) "Nonlinear contribution to the impedance"
Ztrans_ana ((tp+EC)*Z1+Z2) "Transfer impedance (analytical, normalized)"