摘要
与传统整体式RANS/LES混合方法相比,嵌入式RANS/LES混合方法不再依靠改进后的湍流模型本身或网格疏密自动划分流场中的RANS区域和LES区域,而是通过对流动现象的预估,人为将LES区域嵌入到RANS区域,从而使RANS区过渡到LES区的交界面尽可能与流向垂直,方便合理附加额外的湍流脉动信息。这样做不但确保了LES在某些复杂流动区域彻底支配地位,更重要的是能够避免RANS区对LES区解析湍流发展的污染和抑制。将槽道流场划分为上游RANS区和下游LES区,在经典的SST-DES模型基础上,采用合成涡方法生成交界面的湍流信息,取得了良好的模拟结果。
As compared with traditional global hybrid RANS/LES method, embedded hybrid RANS/LES method does not treat the whole field as different RANS or LES regions automatically based on the turbulence model itself or whether the mesh is fine or not. It is aimed to embed any LES part to the background RANS flow artificially so that the interface between RANS and LES is set vertically to the streamwise direction and the extra resolved turbulence information in the interface can be easily and rationally added. That means, it can not only make sure that LES con- trois the flow principles totally in the regions of complex flow phenomena but also avoid the pollution from RANS and overcome the delay of resolved turbulence in LES regions. In this paper channel flow is divided into upstream RANS and downstream LES regions, and SST-DES is used as the basic hybrid model, together with the additional turbulent fluctuations generated from synthetic eddy method in the interface, which finally lead to a satisfactory sim- ulation.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2015年第5期799-803,共5页
Journal of Northwestern Polytechnical University
基金
国家自然科学基金面上项目(11072200)资助
关键词
嵌入式RANS/LES混合方法
SST-DES
合成涡方法
槽道流动
数值模拟
channel flow, computer simulation, drag coefficient, flow fields, friction, large eddy simulation, mo-mentum, Navier Stokes equations, Reynolds number, tensors, turbulence models, velocity distribu-tion
embedded hybrid RANS/LES method, SST-DES, Synthetic Eddy Method（SEM）
