发展了气动噪声高精度数值模拟方法,空间导数离散采用了HDCS-E8T7格式及精度与之匹配的边界格式,时间离散方法采用了高精度多步龙格库塔方法和高精度隐式双时间步方法,发展了高精度对接边界算法,将方法推广至多块对接网格以满足解决复杂几何构型问题的需要,采用隐式大涡的概念处理可能出现的湍流问题。在此基础上,研究了几何守恒律对计算结果的影响,展示了复杂网格中高精度计算满足几何守恒律的重要性,完成了等熵涡、双圆柱散射、串列柱翼构型和喷嘴射流等典型噪声问题的求解,所得计算结果展示了所发展的模拟方法具有良好的预测精度和解决复杂构型气动噪声问题的潜力。
Noise prediction using high-order numerical method is one of the most interested research top-ics in CFD.HDCS-E8T7 scheme is a seventh-order hybrid linear compact dissipative scheme.This scheme o-vercomes the disadvantage that many high-order finite difference schemes may have when geometric conser-vation law (GCL)is not satisfied,the numerical instability phenomenon may be avoided when the HDCS-E8T7 is applied to solve aeroacoustic problem in complex geometry.In the present high-order numerical noise prediction method,the spatial discretization adopts HDCS-E8T7 scheme and its boundary schemes have suitable accuracy comparing with the interior scheme.High-order multi-step Runge-Kutta and dual stepping scheme are employed for time integration,high-order interface boundary scheme is developed to extend the present method to multi-block point matched grid which meets the need of solving problem in complex geom-etry and the turbulence is handled by the concept of implicit large eddy simulation.Based on this method, the effect of GCL on the numerical solutions is studied.The importance of satisfying the GCL on complex grid for high-order simulation is illuminated.Some typical noise cases,such as vortex convection,scattering of acoustic waves by multiple cylinder,sound radiated by a rod-airfoil configuration and jet noise from noz-zle,are investigated.The solutions of these tests show that the presented method has high prediction accura-cy and potential application for handling aeroacoustic problem on complex geometry.