Abstract:In order to reduce amplitude of pressure fluctuation in a hydraulic turbine, a single-stage centrifugal pump was used as hydraulic turbine. A set of negative curvature guide vane was added next to the impeller outer diameter, then the performance of the turbine was studied experimentally. The geometric model of the turbine was established using Pro/E software, and the vibrational rule of pressure and pressure fluctuation in various flow passages in the turbines with and without guide vanes was calculated by means of the SST k-ω turbulence model and a CFD software. Additionally, the pressure fluctuation signals in time domain were transformed into frequency domain by making use of fast Fourier transform(FFT), finally, the distribution of pressure fluctuation in both domains were analysed. It is shown that the amplitude of pressure fluctuation in the dominated frequency and the maximum pressure fluctuation are both reduced in the volute with guide vanes, but also the amplitude of pressure fluctuation is decreased in the impeller. Meanwhile, in the draft tube, the fluid flow is stable without vortex, making the amplitude of pressure fluctuation in the dominated frequency decreases greatly. Therefore, the method of adding guide vanes can improve the performance of a pump as hydraulic turbine and reduce the amplitude of pressure fluctuation in its flow passages.
史广泰, 刘小兵, 魏文景, 刘洋. 含导叶的液力透平内部压力脉动特性[J]. 排灌机械工程学报, 2017, 35(1): 6-12.
SHI Guangtai, LIU Xiaobing, WEI Wenjing, LIU Yang. Pressure pulsation characteristics in pump as hydraulic turbine with guide vanes. Journal of Drainage and Irrigation Machinery Engin, 2017, 35(1): 6-12.
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