Air Noise Control Optimization Method Of Cabin Based On Ray-tracing Method

The control of cabin noise is one of the main contents of modern ship design.The noise control of ship cabin has many characteristics,such as multi sound source,multi transmission path and resource restriction.It is very important to develop the method of noise control optimization for the guidance of the fine design of ship cabin.In order to solve this problem,this paper studies the optimization method of cabin noise control.First of all,the acoustic ray tracing method in geometric acoustics is introduced into the prediction of ship cabin noise.According to the characteristics of acoustic wave in the ship cabin,research from many aspects,such as sound source simulation,transmission coefficient,reflection coefficient,sound absorption coefficient and so on.The prediction method of ship cabin sound field is established by the numbers based on the acoustic ray tracing method.The applicable frequency range is given.Using this method,the sound field distribution in a typical cabin is calculated.The effectiveness of the method is verified by comparing with the statistical energy method.This method can solve the problem of local noise prediction in the middle and high frequency range and simulation of a directional sound source.Secondly,in order to study the application of the method in cabin noise reduction measures,the calculation formula of sound absorption coefficient is applied to the sound ray tracing method.The calculation principle of sound absorption coefficient and the sound absorption properties of absorbing material are studied.Improved electro acoustic analogy method is proposed,and the formula for calculating the sound absorption coefficient of the parallel perforated plate,composite sound absorption structure with double layer perforated plate and the composite structure of layered porous material is derived in this paper.The noise reduction effect of these sound absorbing material in cabin by acoustic ray tracing method is studied.At the same time,the noise reduction effect test of typical cabin is carried out to verify the validity of theoretical calculation.Finally,based on the principle and data of the acoustic ray tracing method in the cabin noise prediction,the acoustic ray search method,which is the optimization method of noise reduction is put forward.The acoustic sensitivity of the different positions of the bulkhead to the target cabin noise is calculated by searching the acoustic ray supplying energy to the target cabin.According to the results of s acoustic sensitivity,the noise reduction scheme of ship cabin is presented to optimize noise of medium-high frequency in cabin.At the same time,the validity of the method is verified by comparison with statistical energy method.This method can be used to guide the precision design of ship cabin noise reduction.This research is supported by the submarine acoustic stealth technology Key Laboratory of national defense science and technology.