To elucidate the influences of the outlet position of splitter blades on the performance of a low-specific-speed centrifugal pump, two different splitter blade schemes were proposed: one located in the middle of the channel and the other having a deviation angle at the trailing edge of splitter blade toward the suction side of the main blade. Experiments on the model pump with different splitter blade schemes were conducted, and numerical simulations on internal flow characteristics in the impellers were studied by means of the shear stress transport k-ω turbulence model. The results suggest that there is a good agreement between the experimental and numerical results. The splitter blade schemes can effectively optimize the structure of the jet-wake pattern and improve the internal flow states in the impeller channel. In addition, the secondary flow and inlet circulation on the pressure surface of main blade, the flow separation on the suction side of splitter blade, the pressure coefficient distributions on blade surface can achieve an evident amelioration when the trailing edge of splitter blade toward the suction side of the main blade is mounted at an appropriate position.

A combination of experimental and numerical simulation was carried out to analyze the influences of the splitter blade deflection on the performance and pressure fluctuation in low specific speed pumps with and without splitter blades under different flow rates. Performance experiments and particle image velocimetry (PIV) tests were performed to verify the results of the numerical calculation. Several monitoring points were placed in the calculation model pump to collect the pressure fluctuation signals, which were processed by Fast Fourier Transform to obtain the frequency results for further analysis. In addition, turbulence intensity and relative velocity distribution were also analyzed in the regions of the impeller and volute. The results showed that compared with a prototype without a splitter blade and the splitter blade schemes, the maximum pressure pulsation amplitudes are the lowest at different monitoring points of the model pump when the splitter blade deflects to the suction side of the main blade. The variation of pressure pulsation amplitude in this scheme is relatively stable with the change of flow rates compared with other schemes. Furthermore, the impeller scheme with an appropriate deflection of the splitter blade has the lowest turbulence intensity and optimal relative velocity distribution in the main flow passage. Therefore, this paper proposes a reference scheme of the impeller with the splitter blade to effectively decrease the predominate pressure pulsation amplitude.

The pumped hydro energy storage is the most effective way to store large-scale electricity and has been widely used in the world. As the key equipment in the pumped hydro energy storage, it is significant and urgent to improve the performance and operation stability of the pump-turbine. In this study, the effect of runners with and without splitter blade on the performances and inner flow characteristics of a pump-turbine in pump mode was analyzed by the method of numerical calculation. The results suggest that larger tangential velocity at runner outlet and higher pressure at the trailing edge of pressure side in splitter blade runner scheme contribute to higher head. The area of backflow at runner outlet, the highest values of entropy generation rate, and vorticity distribution in splitter blade runner scheme are well smaller than those in prototype runner without splitter blade, which is conducive to improving model performance.

Cavitation performance is a key parameter for a mine high-speed rescue pump, which reduces the stability and reliability of the entire unit. In this study, an experimental method was used to investigate the cavitation characteristics of an inducer installed on the impeller upstream. Hydraulic performance without cavitation was determined along with the cavitation performance, and a visualization experiment was implemented. The inducer head slightly decreased when the cavitation number started to decline; however, it dropped significantly thereafter. At 4200 r/min, anti-cavitation ability of the inducer had no connection with the blade numbers. The anti-cavitation performance of the inducer with three blades was superior than that of the inducer with two blades. The law governing shaft power, cavitation number, and rotating speed disagreed with the similarity law theory. Moreover, the inducer efficiency was higher at greater speeds. The evolution of cavitation bubbles was categorized into the inception, developing, and developed stages. When the cavitation number decreased, vortex cavitation was induced along with the tip leakage vortex; subsequently, wedge-shaped sheet cavitation occurred, which was followed by back-flow vortex cavitation. The areas associated with wedge-shape sheet cavitation and back-flow vortex cavitation increased gradually, extending spirally along the axial direction until the entire flow passage was blocked. Overall, the heads declined by 1.1%–1.9% for the inducer with three and two blades, respectively.

Effects of the Splitter Blade on the Performance of a Pump-Turbine in Pump Mode" [ ], the tags of two flow rates in Figure should be reversed. e corrected figure is shown below.