Abstract：The numerical calculation of multipole expansions in FMBEM was investigated, the models of four points translation relationship to single level and multi-level were built. According to comparing with the theoretical value of Green’ function and it’s normal derivative, the computational accuracy of multipole expansions in sound-absorbing materials and air was studied under the two relationship. Results indicated that, the computational accuracy which was derived from the calculation of expansions with complex wavenumber was related to the value of truncation number, when the product of wavenumber’s imaginary part and the distance of transitive points was too big, the expansion’s value began to go far away from the true value. Finally, two methods were proposed to solve this problem. Furthermore, the transmission loss of a dissipative expansion chamber silencer was calculated as an example, the availability and the feasibility of present paper’s methods were validated.
崔晓兵;季振林. 快速多极子边界元法在吸声材料声场计算中的应用[J]. , 2011, 30(8): 187-192.
Cui Xiao-bing;Ji Zhen-lin. Application of FMBEM to Calculation of Sound Fields in Sound-absorbing Materials. , 2011, 30(8): 187-192.
2011, Vol. 30 
