Effects of air-filled cavity distribution on acoustic absorption performance of anechoic coatings

Abstract

    Submarines are often covered with resonant sound absorbers known as anechoic coatings or tiles in order to avoid detection by sonar. A simulation-based model is developed for predicting the acoustic properties of underwater anechoic structures having matrix viscoelastic materials containing air-filled cavities. In order to validate the proposed modeling, the preliminary numerical results of an anechoic configuration are first compared with available literature data. Then, a systematic investigation of the effects of the periodic air-filled cavity distribution on the acoustic absorbing property of anechoic layer is conducted. It can be stated from the obtained results that tuning the air-filled cavity distribution such as the location and porosity allows broadening and tailoring the acoustic performance of considered anechoic coating over some specific bands or a whole range of frequency.