采用Fluent UDF构造Realizable k-ε/LES、SST k-ε/LES和Spalart-Allmaras/LES 3种RANS/LES混合模型,并对汽车的气动噪声进行数值模拟. 在近壁面采用RANS湍流模型求解,而远离物面的分离区域内的大尺度运动则用LES求解,将3种混合模型的计算结果与全LES湍流模型和风洞试验结果进行了比较. 结果表明,3种混合模型对气动噪声的计算精度高于LES湍流模型;Realizable k-ε/LES和SST k-ε/LES混合模型数值模拟结果与试验值的相对误差均小于5%,而其中Realizable k-ε/LES混合模型更为准确和高效,消耗的计算资源更少.%Realizable k-ε/LES, SST k-ω/LES and Spalart-Allmaras/LES three different hybrid RANS/LES models are constructed by using Fluent UDF to conduct a numerical simulation on the aerodynamic noise of vehicle. The flow field in near-wall area is solved by using RANS turbulence model, while the large-scale motion of separation region away from wall is solved by LES model. Then the calculation results of three hybrid models are compared with that of full LES turbulence model and wind tunnel test. The results show that the aerodynamic noise calculation accuracies of three hybrid models are higher than that of LES turbulence model. The relative errors of numerical simulation with Realizable/LES and SST/LES hybrid models relative to test data are both less than 5%, in which Realizable k-ε/LES hybrid model is even more accurate and efficient and consume less computing resources.
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