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 spat...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.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50579025, 90210005).
文摘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.
