Reconstruction of turbulent fluctuations using a hybrid RANS/LES approach

[摘要] A hybrid RANS/LES approach is presented and assessed considering several flows, which can be interpreted as the most general case of the NLDE approach as defined by Morris et al. [P. J. Morris, L. N. Long, A. Bangalore, and A. Wang, J. Comput. Phys. 133, 56 (1997)]. A decomposition into three parts of the exact solution of the Navier-Stokes equations is considered: mean flow, resolved fluctuations, and unresolved (subgrid) fluctuations. The mean flow is computed using a classical RANS method, while resolved fluctuations are derived from a LES method. This approach is succesfully assessed on the stationary and the pulsed plane channel flow configurations. The case of the flow around a low-pressure turbine blade is discussed in a second step. The hybrid method is also demonstrated to be robust with respect to several sources of error,and provides good results in the case of a coarsened grid simulation, a reduced computational domain simulation, and nonconsistent mean flow fields. (C) 2002 Elsevier Science (USA).

[发布日期] 2002-10-10

[关键词] Navier-Stokes equations;Reynolds averaged Navier-Stokes;large eddy simulation;turbulence