圆柱绕流噪声预报的流场与声场模拟方法对比研究

以三维圆柱为研究对象,使用Lighthill声类比法研究其绕流发声问题。第一步进行流场计算,分别用大涡模拟(LES)、脱体涡模拟(DES)和瞬态雷诺平均法(URANS)模拟声源区流场,通过对比流场压力和涡量等参数,据此选取合适的流场仿真方法;第二步用基于Lighthill方程FW-H积分法和边界元法预报远场直发声,通过和Revell试验结果比较,分析各种计算方法差别。研究表明:进行流场仿真时LES计算结果最好,IDDES法在保证计算精度条件下能有效减少流场网格数量,URANS法误差很大;进行辐射噪声预报时,FW-H积分法和边界元法基本相同。

Comparative Study on the Flow Field and Acoustic Field Simulation for Noise Prediction Induced by the Flow around a Cylinder

Lighthill acoustic analogy method is used to predict the sound generated by flow past a three dimensional cylinder. Firstly, the flow field of sound source is predicted by large-eddy simulation, Detached-Eddy Simulation and Unsteady Reynolds-Average Method respectively, methods to simulate the flow field are selected via contrasting the contours of vorticity and pressure. Secondly, FW-H integral equation method and BEM method based on Lighthill acoustic analogy equation are used to predict noise at far field, difference among these methods is researched by comparing with Revell’s experiment data. Researches show that the flow field simulation result of LES has a greatest agreement with experiment, IDDES has a better compromise with the precision and number of grid, URANS is the worst prediction method. FW-H integral equation method is same as BEM method in predicting radiation noise.