Axisymmetric wave propagation in gas shear flow confined by a rigid-walled pipeline*
Chen Yonga)†, Huang Yi-Yonga), Chen Xiao-Qiana), Bai Yu-Zhua), Tan Xiao-Dongb)
       
Relative phase velocities (a) and attenuation coefficients (b) of the fundamental mode in the upstream propagation for different models. See Fig.  2 for the interpretation of the legends.