大型二维稳态声场问题的一种预测方法

A EFFICIENT PREDICTION METHOD FOR STEADY-STATE DYNAMIC ANALYSIS OF TWO DIMENSIONAL LARGE ACOUSTIC DOMAIN PROBLEM

对于大型二维稳态声场问题,本文提出了一种基于间接Trefftz方法的波数法.在该方法中,声压响应解用一组精确满足Helmholtz控制方程的波函数通解和由外部激励在自由空间产生的特解来近似表示.通过在边界上采用加权余量法得到各个波函数的系数,从而得到所求声场的声压响应.一个60m×40m的大型声场算例表明,得到相同精度和收敛性的结果时,波数法比BEM所需的自由度少.

A wave number method （ WNM ） was proposed to deal with the steady - state mid - frequency acoustic problem. Based on an indirect Trefftz approach, the dynamic pressure response variable was approximated by a set of wave functions, which exactly satisfied the Helmholtz equation. The set of wave functions comprised the exact solutions of the homogeneous part of the governing equations and some particular solution functions, which were derived from the external excitations. The coefficients of the wave functions could be obtained by enforcing the pressure approximation to satisfy the boundary conditions, on which the weighted residual formulation was applied. The results show that the WNM can obtain the same accuracy and convergence as the BEM with less degrees of freedoms.