This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance...This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance region of guide vane cascade, the Reynolds stressdifferential model was used for turbulence closure, and the body-fitted curvilinear coordinates andthe SIMPLE! algorithm were adopted. The governing equations were discretized with the non-staggeredgrids by means of the finite volume method. Detailed comparison of hydrodynamical characteristics ofguide vane in hydraulic turbine with or without tip gap was made. Special attention was paid to theinfluence of leakage flow on the main flow and to the movement of tip leakage flow in the end guidevane. The position and strength of the roll-vortex on the sides of guide vane in were determined.The numerical solutions agree with the experimental results obtained by particle image ve-locimetry.The results help to clarify the loss, wear and cavi-tation erosion between the guide vane andrings, especially for those used in the Yellow River which has a high sediment content.展开更多
文摘This paper presents numerical and experimental results of the flow in the tipclearance region of the guide vane row in hydraulic turbine. The 3-D Navier-Stokes equations wereemployed to model the flow in end clearance region of guide vane cascade, the Reynolds stressdifferential model was used for turbulence closure, and the body-fitted curvilinear coordinates andthe SIMPLE! algorithm were adopted. The governing equations were discretized with the non-staggeredgrids by means of the finite volume method. Detailed comparison of hydrodynamical characteristics ofguide vane in hydraulic turbine with or without tip gap was made. Special attention was paid to theinfluence of leakage flow on the main flow and to the movement of tip leakage flow in the end guidevane. The position and strength of the roll-vortex on the sides of guide vane in were determined.The numerical solutions agree with the experimental results obtained by particle image ve-locimetry.The results help to clarify the loss, wear and cavi-tation erosion between the guide vane andrings, especially for those used in the Yellow River which has a high sediment content.
