摘要
以J150涡轮增压压气机为研究对象,采用数值方法研究了叶轮后缘掠对离心压气机的气动性能影响,着重分析了叶尖掠的方向与角度的影响及其作用机理。结果表明:在一定掠角范围内,叶轮后缘叶尖掠可使全工况总压比都发生不同幅度变化,前掠降低压比、后掠提高压比。对绝热效率也有一定影响,前掠降低效率、后掠提高效率,但对效率性能的影响程度要比对总压比性能的影响程度小。对流量域影响相对较小。后缘掠对叶轮与无叶扩压器的全流域范围内气体流动状态都有影响,但叶轮的主要影响范围为主叶片后半弦长,即分流叶片全弦长。叶轮后缘的叶尖掠对压气机内部流场的作用机理:由前掠向后掠变化时,随着后掠角的增大,叶片的承压面积增大、做功能力增强、出口压力提升,改善叶轮后缘气体流动状况;但出口压力分布不均匀性加深,造成下游无叶扩压器的总压损失、熵增损失增大;当扩压器性能的损失大于叶轮性能的增益,离心压气机性能就开始下降。因此,后掠角具有最优值(15°),可升压4.07%、增效1.40%。
Taking J150 turbocharger as the research object,the influence of impeller trailing edge sweep on the aerodynamic performance of centrifugal compressor was studied numerically.Different direction and angle of tip sweep are analyzed emphatically.The results indicate that the tip sweep of the impeller trailing edge make the total pressure ratio change under all working conditions within a certain sweep angle range.The forward sweep of impeller trailing edge reduces the pressure ratio,while the backward sweep increases the pressure ratio.It also has a certain influence on the adiabatic efficiency.The forward sweep reduces the efficiency and the backward sweep improves the efficiency,but the effect on the efficiency performance is smaller than the effect on the total pressure ratio performance.The influence of impeller trailing edge sweep on the compressor’s mass flow operating range is relatively small.While it has obvious influence on the gas flow state of the impeller and the vaneless diffuser in the whole mass flow domain,but the main influence range of the impeller is the rear half chord length of the main blade,that is,the full chord length of the splitter blade.Mechanism of influence of impeller trailing edge on compressor internal flow field can be described as:When the tip sweep changing from forward to backward,the pressure bearing area of the impeller increases with the sweep angle increasing.It increases the ability to do work.The outlet pressure increases,which improving the gas flow condition at the trailing edge of the impeller.However,the non-uniformity of the outlet pressure distribution deepens,resulting in an increase in the total pressure loss and entropy increase loss of the downstream vaneless diffuser.When the loss of the diffuser performance is greater than the gain of the impeller performance,the performance of the centrifugal compressor begins to decrease.Therefore,the sweep angle has an optimal value(15°),which can boost the pressure by 4.07% and increase the efficiency by 1.40%.
作者
李文娇
杜礼明
关天民
LI Wenjiao;DU Liming;GUAN Tianmin(College of Mechanical Engineering,Dalian Jiaotong University,Dalian 116028,China;College of Locomotive and Rolling Stock Engineering,Dalian Jiaotong University,Dalian 116028,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2022年第12期3225-3234,共10页
Journal of Engineering Thermophysics
基金
国家自然科学基金资助项目(No.11872136)
辽宁省科学技术基金资助项目(No.201602112)。
关键词
离心压气机
叶轮
后缘
掠形
气动性能
内流场
影响机理
centrifugal compressor
impeller
trailing edge
sweep
aerodynamic performance
internal flow field
influence mechanism
