CAJ | 학술논문

通过寻找满足非紧致边界的精确格林函数，发展了一种基于声模拟理论的非紧致边界气动噪声数值预测方法。该方法首先采用边界积分方法计算满足相应边界条件的精确格林函数，然后采用精确格林函数求解FW-H方程，进行远场气动噪声预测。考虑了非紧致边界对声波传播的散射作用，适用于尺寸较大且几何外形复杂的边界与非定常流动相互作用诱发的气动噪声的数值预测。以雷诺数90000、马赫数0.2的圆柱绕流诱发的气动噪声为例，数值预测了非紧致边界条件下的气动噪声，并与采用自由空间格林函数求解FW-H的计算结果进行了对比，对该方法进行了验证。
통과심조만족비긴치변계적정학격림함수，발전료일충기우성모의이론적비긴치변계기동조성수치예측방법。해방법수선채용변계적분방법계산만족상응변계조건적정학격림함수，연후채용정학격림함수구해FW-H방정，진행원장기동조성예측。고필료비긴치변계대성파전파적산사작용，괄용우척촌교대차궤하외형복잡적변계여비정상류동상호작용유발적기동조성적수치예측。이뢰낙수90000、마혁수0.2적원주요류유발적기동조성위례，수치예측료비긴치변계조건하적기동조성，병여채용자유공간격림함수구해FW-H적계산결과진행료대비，대해방법진행료험증。
A computational method was proposed to evaluate the aerodynamic noise generated by unsteady flow over non-compact boundary. Firstly, the boundary element method was applied to compute the exact Green’s Function that satis-fies the specific boundary conditions. Then, the numerical results of the exact Green’s Function were used to solve the FW-H equation to predict the far field noise. This numerical method can predict the radiation noise from the aerodynamic sources as well as the scattering noise from the non-compact surfaces. Especially, this approach is suitable for the boundaries with large sizes and complex geometric shapes. The present method was applied to predict aerodynamic noise generated by turbu-lent flows at Reynolds number of 90 000 and Mach’s number of 0.2 over a circular cylinder with non-compact boundary conditions. Results were compared with those of FW-H equations based on the free-space Green’s function to verify the ef-fectiveness of this method.