Affiliation：Tokyo Polytechnic University Wind Engineering Research Center
Abstract：Large eddy simulation (LES) is performed to numerically simulate the turbulent flows over hilly terrains with smooth surface. Two types of inflow turbulence generation methods, wind tunnel replication method and consistent discrete random flow generation method, are used to simulate the approaching flows for LES study of turbulent flow fields over simplified topography. The advantages and limitations of these methods are discussed in the context of flow patterns and turbulence characteristics. The performance of three different subgrid-scale models are investigated: standard Smagorinsky model (SM), (b) coherent structure Smagorinsky model (CSM) and dynamic Lagrangian Smagorinsky model (DLSM). The numerical results obtained from the CSM and DLSM are in relatively poor agreement with those of the experiment. The size of the recirculation region predicted by the CSM and DLSM are smaller than that of the SM. It is found that the closed-wake region is formed behind the 2-D ridge, while the open-wake region is established on the leeward side of 3-D hill due to the existence of the secondary flow. The open-wake region is well reproduced by the SM rather than the CSM and DLSM. The non-Gaussian characteristics of wake flow and the topography-driven twist effects are also examined.
Publication related to your research
- Q.S. Yang, T. Zhou, B.W. Yan, P.V. Phuc, W.C. Hu. LES study of turbulent flow fields over hilly terrains: Comparisons of inflow turbulence generation methods and SGS models. Journal of Wind Engineering and Industrial Aerodynamics, Vol 203C, Aug. 2020.
Posted : March 31,2020