Green's function in cylindrical duct

Green's function, kb = 10, m = 2, soft wall, uniform flow (M = 0.5 ), r0 = 0.4

Green's function, kb = 10, m = 2, soft wall, uniform flow (M = 0.5 ), r0 = 0.96

(see Journal of Sound and Vibration 317, 2008, p.994-1016)