1. Faculty of Water Conservation, Yunnan Agricultural University, Kunming, Yunnan 650201, China; 2. Department of Engineering Mechanics, Kunming University of Science and Technology, Kunming, Yunnan 650500, China
Numerical simulation of turbulent flow around a vane in the channel with guide vane closure based on the two-dimensional transient N-S equation was conducted with the standard k-ε turbulence model. In order to study the dynamic effect of the cascade flow field on the fluid-structure interaction occurring between the flow and guide vanes in the transient process of hydro-turbine, the overset meshes and dynamic mesh technology were used in such an unsteady flow problem. The dynamic characteristics of non-uniform flow field show strong nonlinearity under the two methods. The lift and drag coefficients of a guide vane are in good agreement with time. The pressure, vortex structure and turbulence intensity distribution in the channel at the typical time are basically the same. But the mesh number of the overset mesh is about 1/3 of the dynamic mesh, and the computation time is about 1/4 of the dynamic mesh. It is shown that the overset mesh method has better advantages than the dynamic mesh method in terms of computational efficiency. The results show that the two methods can well simulate the dynamic flow around a guide vane. But for some complicated nonlinear dynamic boundary fluid-structure interaction problems, the overset mesh method is preferred. The two methods are of higher engineering application value.
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