| This thesis is supported by the National Natural Science Foundation Emphases Item of China (90410019). Hydraulic turbine is main component of energy conversion in PowerStation and whose performance directly affects PowerStation's benefit, so it looks important to pre-evaluate performance during designing the turbine. In order to overcome the disadvantages of model experiment such as long period and great investment, this paper carries out the flow computation based on N-S equation and forecasts the performance.MDT is used to build hydraulic turbine's three-dimensions solid and model of flow calculation can be realized. It adopts Reynolds time-average N-S equation and k-s turbulence model to calculate the inner 3-D viscid turbulence flow of hydraulic turbine. In the unstructured grid, the governing equations are discredited with Finite Volume Method based on Finite Element Method. And the pressure correction method is proposed in numerical calculations. Flux is pre-evaluated based on three-dimension viscous confused flow calculation. As the flux is unknown in advanced, we would suppose a flux value, three-dimension viscous confused flow of hydraulic turbine is calculated according to the supposed flux value and academic head will be calculated on basis of results. Put academic head into compare with experimental head. If difference meet the need, we can confirm the flux and pre-evaluate energy performance and cavitations performance, otherwise revise flux value and make iterative calculation until head differencemeet the need. According to aforesaid, the method mentioned in this paper has been realized. Through analysis of France turbine, flux, energy performances and cavitations performances are pre-evaluated. Hill chart is drawn based on pre-evaluated results. Compare is carried through between calculation result and experimental data, all the results show that the method used in this paper to pre-evaluate France turbine's performance is feasible. |
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