复合叶轮出口角及分流叶片偏置对高速燃油泵性能的影响研究

The Study on the Effects of Composite Impeller Outlet Angle and Splitter Blade Offsets on the Performance of High-speed Fuel Pumps

为研究叶轮出口角以及分流叶片布置方式对高速超低比转速燃油泵扬程和效率的影响规律,选取复合叶轮的4个因素,叶片出口角β_(2)、叶片数z、分流叶片周向偏置度θ和偏转角α,基于正交试验设计法设计16组不同参数及结构的复合叶轮,对正交试验结果进行极差分析后得出各因素对扬程和效率的影响规律以及主次顺序,并最终得到高速燃油泵复合叶轮的最佳设计方案。其次,基于CFD数值模拟对常规无分流叶片设计方案与最佳设计方案进行外特性及流场分析,结果表明:最佳方案的扬程和效率在整个模拟工况内均有所提升,其中在实际工况Q为0.5 m~3/h下扬程较常规方案提高了10.4%,效率提高了4.8%。除此之外,最佳方案实际工况下的内流场压力分布与速度分布更加均匀,有效削弱了叶轮流道内的大尺度旋涡以及间隙泄漏对主流的干扰作用。

To investigate the effects of impeller outlet angle and splitter blade arrangement on the head and efficiency of high-speed,ultra-low specific speed fuel pumps,four factors of composite impeller including blade outlet angle β_2,number of blades z,circumferential offset degree θ of splitter blades,and deflection angle α were selected.Based on orthogonal experimental design,16 groups of composite impellers with different parameters and structures were designed,and the range analysis of orthogonal experimental results was conducted to obtain the influence rules and primary-secondary sequence of each factor on the head and efficiency.Finally,the optimal design scheme of the composite impeller for high-speed fuel pumps was obtained.Furthermore,based on CFD numerical simulation,the external characteristics and flow field analysis of the conventional non-splitter blade design scheme and the optimal design scheme were conducted.The results showed that the head and efficiency of the optimal scheme were improved in the entire simulation condition.Among them,under the actual operating condition of Q=0.5 m~3/h,the head was increased by 10.4% and the efficiency was increased by 4.8% compared with the conventional scheme.In addition,the pressure distribution and velocity distribution of the internal flow field of the optimal scheme were more uniform under the actual operating condition,effectively reducing the interference of large-scale vortices and clearance leakage in the impeller flow passage on the main flow.