声散射计算中的参数关联时域有限差分法

Parameter Relevancy Finite-Difference Time-Domain Method in Acoustic Scattering Calculation

利用理想流体介质中小振幅声场是无旋场的特性,得到各振速分量之间的新的差分表达式,提出参数关联时域有限差分法(the Paramete rRelevancy Finite-Difference Time-Domain:PR-FDTD)。它不改变标准FDTD方法的时空离散和场分量配置方式,而是利用参数之间的新关系,通过特定的空间递推顺序,把所须存储的声场分量减少,最多可节省约33%的内存。以二维圆柱体和方柱体为例进行仿真计算,结果表明:PR-FDTD在节省内存的同时,计算精度与标准FDTD方法相当。

The characteristic that the acoustic field with very little amplitude was no curl in ideal fluid media was used to derive new difference expressions between the components of velocity, and the Parameter Relevancy Finite-Difference Time-Domain （PR-FDTD） Method was proposed. This method did not change the ways of space-time discretization and the field components configuration of normal FDTD method, but make use of new relation between the parameters and special recurrence relation to reduce the number of field components which needed to store, and it couM save about 33% storage at most. Results of simulations for two-dimensional cylinder and cube show that the accuracy Of PR-FDTD is equal to that of the normal FDTD while saving the memory.