Large eddy simulation of turbulent flow around moving guide vane of adjusting hydro turbine
Huang Jianfeng1, Zhang Lixiang1, Guo Yakun2
1.Department of Engineering Mechanics, Kunming University of Science and Technology, Kunming, Yunnan 650051, China; 2.School of Engineering, University of Aberdeen, Aberdeen, AB24 3UE, UK
Abstract：To investigate transient hydraulic process of upstream duct system and hydro turbine, based on the incompressible viscous Navier-Stokes equations and immersed boundary method(IBM)for moving boundary, using the dynamical subgrid stresses(SGS)on Smagorinsky-Lilly model in large eddy simulation(LES), a delicate numerical simulation of three dimensional turbulent flow around one moving guide vane of a benchmark hydro turbine unit in a channel was conducted. The distributions of the pressure and the topological structures of wake were well captured as closure of the vane. The production and evolution of the wake vortices passing the kinetic guide vane was clearly shown, and the physics of the structures were analyzed. The results show that the flow around a moving guide vane will produce numerous complex transient structure which induces water hammer of upstream duct system and transient behavior of downstream runner passage. The numerical results show that the numerical method of LES-IBM with dynamical Smagorinsky-Lilly SGS model can be used to well simulate the interaction between high Reynolds number turbulent flow with motion of the vane closure, revealing the mechanism evolution properties of the wake to the downstream in the hydro turbine adjustment process.
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