W 100 "Domain width"
dW 20 "Absorbing layer width"
c0 1 "Speed of sound"
rho0 1 "Background density"
p0 1[atm]/(c0^2*rho0) "Background pressure"
alpha log(2)/9 "Gaussian pulse width"
beta 0.04 "Gaussian pulse velocity factor"
Ma 0.5 "Mach number"