k0 lnsf.omega/(lnsf.c0+Uin) "Convected wave number"
pb 1[Pa]*exp(-i*k0*z) "Background acoustic pressure"
ub 0 "Background acoustic x-velocity"
vb 0 "Background acoustic y-velocity"
wb -1/(lnsf.iomega*lnsf.rho0)*d(pb,z) "Background acoustic z-velocity"
Tb lnsf.alpha_p*lnsf.T0/(lnsf.rho0*lnsf.Cp)*pb "Background acoustic temperature"