Implementation of a Roughness Element to Trip Transition in Large-eddy Simulation  

作　　者：J.Boudet J.-F.Monier F.Gao 

机构地区：[1]LMFA, Ecole Centrale de Lyon [2]Université de Lyon–UMR CNRS 5509,69134 Ecully Cedex, France PhD.Candidate [3]Université de Lyon–UMR CNRS 5509,69134 Ecully Cedex, France

出　　处：《Journal of Thermal Science》2015年第1期30-36,共7页热科学学报（英文版）

摘　　要：In aerodynamics, the laminar or turbulent regime of a boundary layer has a strong influence on friction or heat transfer. In practical applications, it is sometimes necessary to trip the transition to turbulent, and a common way is by use of a roughness element （e.g. a step） on the wall. The present paper is concerned with the numerical im- plementation of such a trip in large-eddy simulations. The study is carried out on a flat-plate boundary layer con- figuration, with Reynolds number Rex=l.3x 106. First, this work brings the opportunity to introduce a practical methodology to assess convergence in large-eddy simulations. Second, concerning the trip implementation, a volume source term is proposed and is shown to yield a smoother and faster transition than a grid step. Moreover, it is easier to implement and more adaptable. Finally, two subgrid-scale models are tested： the WALE model of Nic0ud and Ducros （Flow Turbul. Combust., vol. 62, 1999） and the shear-improved Smagorinsky model of Ldv^que et al. （J. Fluid Mech., vol. 570, 2007）. Both models allow transition, but the former appears to yield a faster transition and a better prediction of friction in the turbulent regime.

关 键 词：large-eddy simulation boundary layer roughness element TRANSITION TRIPPING 

分 类 号：O355[理学—流体力学]