Numerical Investigations of Model Propeller Turbine Performance Under Different Guide Vane Opening

In the paper, CFD method is applied to investigate model propeller turbine performance under different guide vane opening. First, the whole passage geometric models of model propeller turbine have been built with 0° runner blade under five kinds of guide vane opening, and subdivided with about 1.78 million cells of unstructured mesh. Then, three dimensional turbulent flow computations are made at the water head of H = 1m and the runner speed of n = 217.4 r/min, with the two turbulent models, RNG k-ε and Spalart-Allmadas. Furthermore, the curves of moment value and axial hydraulic thrust value are plotted and compared with experimental curves, which shows that numerical results agree well with experimental data, and Spalart-Allmadas model has better precision than RNG k-ε model. Finally, the flow fields of different parts in the turbine passage are displayed and analyzed respectively under the large, normal and small guide vane opening, which shows the fact that the rotating direction of vortex in the axial diffuse of draft tube is opposite by comparing the large opening with the small opening, and the flow field is in disorder and unsteady especially under the small opening. On the whole, CFD method has many unique advantages and has played more and more important roles on the investigations of hydro turbine performance.