履带式两栖运输设备多湍流模型的研究

Study on Turbulence Models for Simulation on Flow Field Around Tracked Amphibious Vehicle

关于履带式两栖运输设备精确建模问题,针对履带式两栖运输设备水上受湍流影响大,但湍流模型难于选择的问题,为达到使用恰当湍流模型提高仿真精度的目的,采用对比阻力系数和绕流场云图的方法进行湍流模型适用性的研究,明确各种湍流模型的特性。以某型履带式两栖运输设备水下绕流场为计算对象,基于RANS方程的求解,分别采用Spalart-All-maras、标准k-ε、RNG k-ε、Realizable k-ε、标准k-ω、SST k-ω湍流模型。对比多组仿真结果,表明Realizable k-ε、SSTk-ω模型计算得到的总阻力相对误差最小,RNG k-ε模型对复杂形体周围流场描绘最详细,Spalart-Allmaras模型也有较好的计算精度。

Numerical simulation of flow field is deeply effected by turbulence model,but turbulence model is hard to be chosen.In order to improve the accuracy of simulation by a suitable turbulence model,resistance coefficient and contours of flow field were used to study feature of turbulence model.Underwater flow field around an amphibious vehicle was studied based on the RANS equation with six turbulence models,Spalart-Allmaras,standard k-ε,RNG k-ε,Realizable k-ε,standard k-ω and SST k-ω.The result indicates that the Realizable k-ε and the SST k-ω make the least relative error on total resistance,the RNG k-ε makes the most particular flow field,and the Spalart-Allmaras also makes a good computational accuracy.