Optimum Design And Vibration Characteristics Analysis Of Hydraulic Turbine Components

Studies of unsteady flow in hydraulic turbine components, optimal design and vibration characteristics analysis of hydraulic turbine components are of importance to deeply understand the hydraulic turbine vibrates intrinsic mechanism, improve the comprehensive hydraulic performance of the hydraulic turbine and enhances the operating stability of the water-turbine generator set.Three dimensional unsteady flows in whole passage of hydraulic turbine were simulated in this article. Intensity analysis of runner blade and vibration characteristics analysis of hydraulic turbine components were conducted based on the combination of CFD and FSI. An optimization method for spiral case was proposed based on three dimensional CFD analyses. The method was used to optimize semi-spiral case of one hydraulic power station.(1) Based on the analysis of flow mechanism, the numerical simulation of the steady flow in whole passage of the water turbine was conducted by using Reynolds averaged N-S equation and k-ε turbulence model with double equation. The work was done under three normal operation conditions and three running away conditions. And the flow information in the water turbine was obtained. The results under the running away conditions show that the pressure and velocity distribution on pressure face and suction face of the blade were extremely irregular, there are obvious low pressure zone and eddy flow zone, and the vortex flow in the flow passage was obvious.(2) An attempt has been carried on the 3-D numerical calculation of the unsteady flow in entire flow channel including the spiral case, stay vanes, guide vanes, runner and draft tube. The results indicate that influence of the pressure fluctuation is different on different parts of the blades. Pressure fluctuation has a less effect on inlet than that on outlet. The influence of the pressure fluctuation on the lower ring is less than that on the crown. The influence of the pressure fluctuation on the suction surface of the blade is bigger than that on pressure surface.(3)An optimization method for spiral case was proposed based on three dimensional CFD analyses in view of the problem existing in the actual project application of semi-spiral case. Taking the tail shape of pier in the spiral inlet as subject investigated, the 3-D CFD analysis and...