Unsteady turbulent simulation of Three Gorges hydraulic turbine and analysis of pressure in the whole passage

In this paper,the three-dimensional unsteady turbulent flow is simulated through the whole flow passage of Three Gorge Francis hydraulic turbine.The pressure pulsation are predicted at positions in the draft tube,in front of runner,wicket gate,stay vane,and at the inlet of spiral case.The comparison between the calculated and the experimental results shows that the simulation calculation could simulate the pressure fluctuation in the hydraulic turbine very well.Based on the result analysis,it is demonstrated that the two main factors,which create the pressure pulsation in the turbine,are the unsteady vortex rope in the draft tube and the retor-stator interaction between wicket gates and runner.The results also indicate that the pressure pulsation spread widely inside the whole passage from the draft tube to the spiral case.