结合并行策略与距离减缩法的搜索算法及其在CAA中的应用

为提高流场与声场信息传递效率，建立了一种耦合MPI并行策略与改进距离减缩法的搜索算法。在完成点搜索后，采用一种适合于结构和非结构网格的形函数插值算法进行流场插值，实现了流场信息从流场网格到声场网格的快速传递。针对网格点搜索算法效率的验证，选用二维30P30N三段翼为研究对象，在不同的子进程数下进行对比分析。结果表明，相对于传统的距离减缩算法，本文提出的改进算法能有效提高CAA网格点的搜索效率，并且效率随着子进程数的增加而提高。在此基础上，将建立的流场与声场信息传递技术模块应用于CAA方法中，并对二维NACA0012翼型的后缘噪声问题进行计算分析，计算结果反映基于流场与声场信息快速传递算法的CAA方法能有效模拟宽频气动噪声问题。

A search algorithm coupling parallel strategy and distance decreasing method applied to CAA

A modified search algorithm coupling MPI parallel strategy and distance decreasing method is proposed,while a field function interpolation algorithm for flow field is also introduced.This algorithm is suitable for structured and unstructured meshes,and can transfer flow field information from flow field grid to sound field grid efficiently.For the validation of the grid point search algorithm''s efficiency,the paper chooses two-dimensional 30p30n three-section multi-foil as a subject of study.The results are analyzed under different numbers of child processes,and higher efficiency is achieved as the number of child processes increases.The results also show that:compared with traditional distance decreasing method,this modified method can effectively improve the search efficiency of CAA grid points,and efficiency becomes higher as the number of child processes increases.On this basis,delivery method between flow field and the sound field information is incorporated into CAA method.Then this method is applied to the two-dimensional NACA0012 airfoil''s trailing edge noise and the results show that the method can simulate broadband aerodynamic noise.