Research on the engineering calculation method of acoustic radiation of open-frame multi-cabin structure

The open-frame multi-cabin structure is a common structure for deep-sea underwater vehicles. The numerical method on the vibration and acoustic radiation characteristics of the open-frame multi-cabin structure is of great signi fi cance for the prediction and control of underwater vehicles noise radiation. In this work, an engineering calculation method based on dynamic load identi fi cation in frequency domain was proposed for the acoustic radiation of structures excited by complex vibration sources. The dynamic model of the open-frame multi-cabin structure was established by using the fi nite element method (FEM). The vibration source was replaced by an equivalent load model, and the equivalent load was identi fi ed through the vibration response and the dynamic model of the structure. The key to the equivalent load identi fi cation is the selection of vibration measurement point. A method for selection of vibration measurement point in load identi fi cation process is proposed by predicting vibration response of the accelerometer validation channel. The identi fi ed load was loaded on the structural fi nite element model as an input to calculate the structural dynamic vibration and acoustic radiation. The equivalent load model was proposed for eccentric motors, and the load identi fi ca- tion was veri fi ed on the stiffened plate structure. Using this method, the acoustic radiation of the open-frame multi-cabin structure was calculated and compared with experimental results. The results show that the sound pressure level at the excitation frequency of the vibration source and the overall sound pressure level are in good agreement with the experimental results. This research provides a practical engineering calculation method for radiation noise prediction of underwater vehicles. (c) 2024 Institute of Noise Control Engineering.