【摘要】 为能在带有极点的不平坦底部边界的声波导中实施快速步进计算Helmholtz方程,构造了几种能将弯曲底边界平坦化的非线性、非对称化全局坐标变换,这些变换一方面缓解了坐标曲线的局部"拥挤"状况,另一方面对步进计算中所涉及到的Helmholtz方程特征问题进行分析计算,提高了用Rayleigh迭代计算特征问题的效率,通过比较分析,指出了一个有效计算方法——分段步进法,为大步长计算波的传播提供了可靠的处理方法.更多还原

【Abstract】 For the acoustic waveguide in a region bounded by a flat top and a curved bottom with poles,some kinds of nonlinear and unsymmetrical global coordinate transformations to flatten the curved bottom of the waveguide are constructed to carry out fast marching computation or segment marching computation of Helmholtz equation.These transformations,improve the squeezed coordinate curves raise the effective of Rayleigh iteration for Helmholtz eigenvalue problem involved in the marching method.By comparison,it is pointed that there is and effective marching method called piece marching.更多还原