Numerical study on radiation impedance of underwater sound sources in non-anechoic tank

The radiation impedance is an important index to evaluate the characteristics of underwater sound sources. In this study, a numerical method for calculating the radiation impedance of underwater sound sources using ACTRAN is proposed. The radiation impedance is calculated by extracting the sound pressure and velocity on the surface of the sound sources. To verify the accuracy of the numerical method, the radiation impedance of a pulsating sphere source is calculated and the results are in good agreement with the analytical results. The radiation impedance of an elastic spherical shell in air, anechoic tanks, and non-anechoic tanks is calculated and analyzed. The results show that when the frequency is lower than the lowest normal frequency, the radiation impedance of the elastic spherical shell in anechoic tanks and non-anechoic tanks is consistent. When there are normal modes in non-anechoic tank, the radiation impedance of the elastic spherical shell varies with the normal frequencies. The proposed method can be used to calculate and analyze the radiation impedance of complex structures in different environments.