摘要
The turbulent flow, with the Reynolds number of 5.9×10^5, in the strongly 3-D skew blade passage of a true Francis hydro turbine was simulated by the Large Eddy Simulation （LES） approach to investigate the spatial and temporal distributions of the fully developed turbulence in the passage with strongly 3-D complex geometry. The simulations show that the strong three-dimensionality of the passage has a great amplification effect on the turbulence in the passage, and the distributions of the turbulence are diversely nonuniform, for instance, the rise of turbulent kinetic energy in the lower 1/3 region of the passage is more than 45%, whereas its rise in the upper 1/3 region is less than 1%. With the LES approach, the details of the flow structures at the near-wall surfaces of the blades could be obtained. Several turbulent spots were captured.
The turbulent flow, with the Reynolds number of 5.9×10^5, in the strongly 3-D skew blade passage of a true Francis hydro turbine was simulated by the Large Eddy Simulation （LES） approach to investigate the spatial and temporal distributions of the fully developed turbulence in the passage with strongly 3-D complex geometry. The simulations show that the strong three-dimensionality of the passage has a great amplification effect on the turbulence in the passage, and the distributions of the turbulence are diversely nonuniform, for instance, the rise of turbulent kinetic energy in the lower 1/3 region of the passage is more than 45%, whereas its rise in the upper 1/3 region is less than 1%. With the LES approach, the details of the flow structures at the near-wall surfaces of the blades could be obtained. Several turbulent spots were captured.
基金
Project supported by the National Natural Science Foundation of China (Grant Nos. 50579025, 90210005).
