Mutual-radiation impedance of two coaxial aligned cylindrical shells with finite length

By means of Green's function and the generalized radiation impedance formula, the formulas for modal mutual-radiation impedance of two finite length cylindrical shells with rigid baffle at each end were derived based on the modal expansion technique of a cylindrial shell. Numerical results were also presented for different radial velocity distributions. The results showed that in a lower frequency range, mutual-radiation impedance coefficients between two finite length cylindrical shells are relatively larger; the peaks of mutual-radiation impedance coefficients with the same axial wave number are larger than those with different axial wave number; radiation resistance and reactance coefficients become smaller when the difference of p and m increases; mutual-radiation impedance coefficients generally decrease with increase in lengths of two finite length cylindrical shells or the distance between two cylindrical shells. The results provided a theoretical basis for analyzing the sound characteristics of multi-cabin cylindrical shells.