带喷嘴双通道混流涡轮的性能及流动损失机理  

Performance and Flow Loss Mechanism of a Mixed Flow Turbine with Twin-Entry Nozzled Volute

作　　者：薛颖娴 杨名洋 魏江山 邓康耀[1] 邢卫东 Xue Yingxian;Yang Mingyang;Wei Jiangshan;Deng Kangyao;Xing Weidong(Internal Combustion Engine Institute,Shanghai Jiao Tong University,Shanghai 200240,China;National Key Laboratory of High Pressure Ratio Turbocharging for Diesel Engine,Tianjin 300400,China)

机构地区：[1]上海交通大学内燃机研究所,上海200240 [2]柴油机高增压国家重点实验室,天津300400

出　　处：《内燃机学报》2019年第5期426-433,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(51606121)

摘　　要：研究了带喷嘴双通道蜗壳的混流涡轮在不同进气条件下的涡轮性能,对比分析了近叶根进气和近叶尖进气两种部分进气工况下的流场分布,探讨了不同进气工况下的流动损失机理.结果表明:近叶尖进气和近叶根进气两种工况的流通能力相同,但后者效率高1.5%~2.5%.损失分布分析表明,近叶尖进气和近叶根进气工况下蜗壳内流动损失基本一致,但前者喷嘴内损失较高,而后者叶轮内的损失高.流场分析表明,近叶尖进气时喷嘴进口气流攻角过大导致吸力面前缘发生高强烈流动分离而产生大范围高熵增,而近叶根进气时叶轮通道内产生大尺度的“旋风涡”并产生高熵增.这两个流通部件内的流场特征差别是不同进气条件下涡轮性能差异的产生机制.该研究为带有双通道蜗壳的涡轮气动优化设计提供了理论基础.Performance and detailed flow field of a nozzled turbine with twin-entry volute(developed by Imperial College London)were studied by using experimentally validated numerical method at different admission conditions.Flow distribution under two partial admission conditions of near hub side(referring as HI)and near shroud side(referring as SI)were analyzed in order to study the mechanism of the flow loss.Results show that the efficiency of the HI case is 1.5%-2.5%higher than that of the SI case although their swallowing capacity is the same.The breakdown of the flow loss in turbine components shows that significant discrepancies exist among different admissions.The flow loss in the volute is nearly the same for two cases.However,the loss is moderately higher in the nozzle for SI case at all turbine loadings,but notably lower in the rotor for this case when compared with its counterpart.Flow analysis shows that higher entropy is generated in the nozzle for SI case due to strong flow separation on the suction surfaces near the leading edge because of large incidence angle.On the other hand,the flow aligns well with the vane angle for HI near the hub,but a large size vortex rolls up near the shroud side which corresponds to the high entropy generation.Downstream the nozzle,a‘tornado’vortex is developed in the rotor passages for the HI case,which leads to higher entropy generation and hence higher flow loss in rotor.

关 键 词：混流涡轮 双通道蜗壳 喷嘴 不同进气条件 涡轮性能 

分 类 号：TK413.5[动力工程及工程热物理—动力机械及工程]