Study on the Pressure Pulsation inside Runner with Splitter Blades in Ultra-High Head Turbine

27th IAHR Symposium on Hydraulic Machinery and Systems

Meng, L.^1 ; Zhang, S.P.^1 ; Zhou, L.J.^1 ; Wang, Z.W.^2

College of Water Conservancy and Civil Engineering, China Agricultural University, Beijing, China^1

Department of Thermal Engineering, Tsinghua University, Beijing, China^2

关键词: Best efficiency point;    Blade Surface;    High-efficiency;    Length ratio;    Peak efficiency;    Pressure pulsation;    Splitter blade;    Unsteady simulations;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/22/3/032012/pdf
DOI  :  10.1088/1755-1315/22/3/032012

来源: IOP

【 摘 要 】

Runners with splitter blades were used widely for the high efficiency and stability. In this paper, the unsteady simulation of an ultra-high head turbine at the best efficiency point, 50% and 75% discharge points were established, to analyze the pressure pulsation in the vaneless space, rotating domain and the draft tube. First of all, runners with different length splitter blades and without splitter blades were compared to learn the efficiency and the pressure distribution on the blade surface. And then the amplitude of the pressure pulsation was analysed. The peak efficiency of the runner with splitter blades is remarkably higher than that of the corresponding impeller without splitter blades. And the efficiency of the turbine is the highest when the length ratio of the splitter blades is 0.75 times the main blades. The pressure pulsation characteristics were also influenced, because the amplitudes of the pulsation induced by the RSI phenomenon were changed as a result of more blades. At last, the best design plan of the length of the splitter blades (length ratio=0.825) was obtained, which improved the pressure pulsation characteristics without significant prejudice to the efficiency.