Optimum design of J-Groove for a bulb turbine model to suppress swirl flow in the draft tube

29th IAHR Symposium on Hydraulic Machinery and Systems

Vu, Viet Luyen^1 ; Chen, Zhenmu^1 ; Choi, Young-Do^2

Graduate School, Department of Mechanical Engineering, Mokpo National University, 1666 Youngsan-Ro, Cheonggye-Myeon, Muan-gun, Jeonnam

58554, Korea, Republic of^1

Department of Mechanical Engineering, Institute of New and Renewable Energy Technology Research, Mokpo National University, 1666 Youngsan-Ro, Cheonggye-Myeon, Muan-gun, Jeonnam

58554, Korea, Republic of^2

关键词: Flow instabilities;    Hydroturbines;    Operating condition;    Optimum designs;    Pressure pulsation;    Swirl intensity;    Swirl numbers;    Turbine modeling;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/240/2/022030/pdf
DOI  :  10.1088/1755-1315/240/2/022030

来源: IOP

【 摘 要 】

The swirl flow is generated by rotating runner into a draft tube of a hydro turbine, effects on the performance of the turbines. Due to various operating conditions of a hydro turbine, the variation of swirl intensity causes flow instabilities in the draft tube. Therefore, J-Groove is a group of grooves usually mounted on the draft tube wall of a hydro turbine, is considered for suppressing swirl flow in the bulb turbine model. The influence of the J-Groove on the turbine's performance and pressure pulsation were examined by CFD analysis in the first step. Then, the optimum design of J-Groove will be conducted while considering dimensions as the length ratio, the depth ratio, the angle and the number of grooves in next step. The swirl number was evaluated in the draft tube at various operating conditions to figure inspect the effect of J-Groove to the main flow in downstream of the turbine model. The FFT analysis was employed to analyse the pressure pulsation of the flow in the draft tube of the turbine model.