阵风与叶栅干涉噪声的数值模拟

Numerical Simulation of Gust-Cascade Interaction Noise

采用计算气动声学方法求解二维线化欧拉方程对阵风与叶栅的干涉噪声进行了数值模拟。为减少频散和耗散误差,采用七点四阶频散相关保持有限差分格式进行空间离散;时间推进采用优化的4/6低频散低耗散龙格库塔法;在各边界处均选择或建立了适当的边界条件。首先通过模拟阵风在自由空间中的传播验证了无反射边界条件的可靠性;然后对阵风与平板叶栅的干涉问题进行了模拟,数值结果与精确解符合得很好;最后给出了阵风与NACA-0012翼型叶栅干涉的数值模拟结果,显示了数值求解方法的可行性。

The gust-cascade interaction noise was numerically simulated using computational aeroacoustics by solving the two-dimensional linearized Euler equations. In order to minimize the dispersion and dissipation errors, the dispersion-relation-preserving scheme was applied to perform the spatial discretion and the optimized 4/6 low-dissipation and low-dispersion Rurlge-Kutta scheme was used for the time integration. Appropriate boundary conditions were prescribed or established for various boundaries. The non reflecting boundary conditions were firstly validated by simulating gust convection in the free space. Then the interaction noise due to the gust/fiat plate cascade was simulated. The numerical results agree well with exact solutions. Finally the numerical results of the noise from the gust/cascade （with NACA-0012 airfoil） interaction are presented which demonstrates the feasibility of the numerical procedure.