Prediction of separation flows around a 6:1 prolate spheroid using RANS/LES hybrid approaches
Prediction of separation flows around a 6:1 prolate spheroid using RANS/LES hybrid approaches
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DOI：
10.1007/s10409-007-0073-6
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发表时间：
2007-07
影响因子：
3.5
通讯作者：
Zhixiang Xiao;Yufei Zhang;Jingbo Huang;Haixin Chen;S. Fu
中科院分区：
文献类型：
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作者：
Zhixiang Xiao;Yufei Zhang;Jingbo Huang;Haixin Chen;S. Fu
本文提出了绕6∶1长球面大迎角分离流的混合reynolds -average Navier-Stokes （RANS）和大涡模拟（LES）方法。本文研究的RANS/LES混合方法包括基于Spalart-Allmaras （S-A）的分离涡模拟（DES）、Menter’s -ω剪切应力输移（SST）和弱非线性涡粘公式（Wilcox-Durbin +, WD+）模型的k -ω以及基于SST和WD+模型的分区-RANS/LES方法。通过实现区域混合方法的流动相关混合函数，从壁面附近的RANS到核心流区域的LES的切换是平滑的。所有混合方法都被设计为对附加流具有RANS模式，对分离流具有LES行为。本文的主要目的是将混合方法应用于高雷诺数长形球体高发生率的分离流动。采用具有四阶人工黏度的四阶中心格式进行空间差分。采用具有伪时间子迭代的全隐式上下对称高斯-赛德尔函数作为时间微分。与现有的测量结果进行了压力分布、表面摩擦和速度分布等方面的比较。考虑到对栅格和基本湍流模型的影响，得到了与实验结果较为吻合的结果。
This paper presents hybrid Reynolds-averaged Navier–Stokes (RANS) and large-eddy-simulation (LES) methods for the separated flows at high angles of attack around a 6:1 prolate spheroid. The RANS/LES hybrid methods studied in this work include the detached eddy simulation (DES) based on Spalart–Allmaras (S–A), Menter’sk–ω shear-stress-transport (SST) andk–ω with weakly nonlinear eddy viscosity formulation (Wilcox–Durbin+, WD+) models and the zonal-RANS/LES methods based on the SST and WD+ models. The switch from RANS near the wall to LES in the core flow region is smooth through the implementation of a flow-dependent blending function for the zonal hybrid method. All the hybrid methods are designed to have a RANS mode for the attached flows and have a LES behavior for the separated flows. The main objective of this paper is to apply the hybrid methods for the high Reynolds number separated flows around prolate spheroid at high-incidences. A fourth-order central scheme with fourth-order artificial viscosity is applied for spatial differencing. The fully implicit lower–upper symmetric-Gauss–Seidel with pseudo time sub-iteration is taken as the temporal differentiation. Comparisons with available measurements are carried out for pressure distribution, skin friction, and profiles of velocity, etc. Reasonable agreement with the experiments, accounting for the effect on grids and fundamental turbulence models, is obtained for the separation flows.