复杂几何条件下伴随格林函数的数值求解

发布时间：2019-02-13 04:14

【摘要】：为简化气动噪声预测中复杂边界的网格处理,采用计算气动声学(CAA)方法与浸入式边界方法(IBM)相结合数值求解气动噪声预测所需的伴随格林函数.根据伴随格林函数的基本形式,文中设计了特定的圆柱声散射算例,并将数值结果与解析解对比,分析该方法的计算精度,验证了该方法在复杂几何边界条件下伴随格林函数求解中的适用性.最后应用该方法求解了考虑吊挂安装效应的锯齿型喷管喷流剪切层内的伴随格林函数.结果表明:由于喷流剪切层的散射效应,伴随格林函数在喷流内分布不均匀,最大值比最小值高出3倍以上,反映了喷流内不同区域声源对远场噪声贡献的差别,降噪设计可以重点考虑降低格林函数较大区域的声源强度以达到降低噪声的目的.
[Abstract]:In order to simplify the mesh processing of complex boundary in aerodynamic noise prediction, the adjoint Green's function for aerodynamic noise prediction is solved numerically by combining the computational aero-acoustic (CAA) method with the immersed boundary method (IBM). According to the basic form of the adjoint Green's function, a special example of cylindrical acoustic scattering is designed, and the numerical results are compared with the analytical solution, and the accuracy of the method is analyzed. The applicability of this method to the solution of the adjoint Green's function under complex geometric boundary conditions is verified. Finally, the adjoint Green's function in the jet shear layer of sawtooth nozzle considering the effect of hoisting and mounting is solved by using this method. The results show that due to the scattering effect of the jet shear layer, the distribution of the accompanying Green's function in the jet is not uniform, and the maximum value is more than three times higher than the minimum value, which reflects the difference of the far field noise contribution of the sound sources in different regions of the jet. The noise reduction design can focus on reducing the intensity of the sound source in the larger area of the Green function to reduce the noise.
【作者单位】：北京航空航天大学能源与动力工程学院;欧道明大学数学与统计学院;
【基金】：国家重点基础研究发展计划(2012CB720201) 国家自然科学基金(51476005)
【分类号】：O241.8;O35

【相似文献】