环形喷嘴宽度对高速诱导轮空化特性的影响  

Effect of annular nozzle breadth on cavitation characteristics of high⁃speed inducer

作　　者：赵伟国[1,2] 强欢欢 李兴国 ZHAO Weiguo;QIANG Huanhuan;LI Xingguo(School of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Key Laboratory of Fluid Machinery and System of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]兰州理工大学甘肃省流体机械及系统重点实验室,兰州730050

出　　处：《航空学报》2024年第4期128-141,共14页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52169018)。

摘　　要：为改善高速诱导轮的空化性能,本研究基于喷射原理,以某型号高速离心泵为研究对象,设计1种口环引流装置,并确定原始方案和环形喷嘴宽度分别为1 mm、3 mm、5 mm、7 mm、9 mm共6组方案,通过数值计算与试验验证相结合的方法研究了不同方案对高速离心泵外特性和其流道空泡体积的影响以及不同方案对高速诱导轮能量传递和其流场分布的影响。研究发现:高速诱导轮最先在叶片进口吸力面外缘处发生空化,随着空化数的减小,诱导轮轮毂前端也生成了大量沿中心流道向上游继续扩散的圆锥状空泡,最后充满上游流道呈柱状分布,口环引流装置可以通过引射叶轮出口高压流体对诱导轮进口低压区进行压力补偿,且引射流能有效阻止叶顶间隙泄漏流,从而改善诱导轮的空化性能。但本研究的不同宽度方案对其空化性能的改善程度不同,当环形喷嘴宽度为3 mm时,对高速诱导轮空化性能改善效果最佳,临界空化数较原始方案减小了38.24%,即当宽径比λ为0.074时环形喷嘴宽度最佳。To improve the cavitation performance of the high-speed inducer,this study took a high-speed centrifugal pump as the research object,designed a wear-ring drainage device based on the jet principle,and determined that the original scheme and the annular nozzle breadths are 1 mm,3 mm,5 mm,7 mm and 9 mm,respectively.The in⁃fluence of different schemes on the external characteristics of the high-speed centrifugal pump and the cavitation vol⁃ume of its flow passage,as well as on the energy transfer and the flow field distribution of the high-speed inducer was studied by the method of numerical calculation and experimental verification.It is found that the high-speed inducer first cavitates at the outer edge of the suction surface at the inlet of the blade.With the reduction of the cavitation num⁃ber,a large number of conical cavities continuing to diffuse upstream along the central flow channel are generated at the front end of the inducer hub,and finally fill the upstream flow channel with a columnar distribution.The wear-ring drainage device can compensate the pressure in the low pressure area at the inducer inlet by ejecting high-pressure fluid at the impeller outlet,and the ejecting jet can effectively prevent the tip clearance leakage flow,thus improving the cavitation performance of the inducer.However,different breadth schemes in this study produce different degrees of improvement on its cavitation performance.When the annular nozzle breadth is 3 mm,the cavitation performance of the high-speed inducer is improved best,and the critical cavitation number is reduced by 38.24%compared with the original scheme;that is,when the width diameter ratioλis 0.074,the annular nozzle breadth is the best.

关 键 词：高速诱导轮 喷射原理 口环引流装置 环形喷嘴宽度 空化性能 

分 类 号：V434.21[航空宇航科学与技术—航空宇航推进理论与工程] TH311[机械工程—机械制造及自动化]