径流/混流涡轮性能及流动损失机理对比  

Comparison of Turbine Performance and Flow Loss Mechanism of a Radial/Mixed-Flow Turbine

作　　者：倪庆明 薛颖娴 杨名洋[1] 丁占铭 吴新涛 邓康耀[1] Ni Qingming;Xue Yingxian;Yang Mingyang;Ding Zhanming;Wu Xintao;Deng Kangyao(Institute of Advanced Energy and Powertrain Technology,Shanghai Jiao Tong University,Shanghai 200240,China;National Key Laboratory of High-Pressure Ratio Turbocharging for Diesel Engine,China North Engine Research Institute,Tianjin 300400,China)

机构地区：[1]上海交通大学新能源动力研究所,上海200240 [2]北方发动机研究所柴油机高增压国家重点实验室,天津300400

出　　处：《内燃机学报》2024年第3期271-278,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(52076130).

摘　　要：针对径流涡轮高效运行域相对狭窄,无法适应发动机变海拔运行时对涡轮宽域高效运行范围的需求问题,结合试验和仿真方法对比分析了相同流通能力的径流涡轮与混流涡轮的性能特征与流动损失机理,结果表明:混流涡轮效率较径流叶轮全工况下平均提高4.5%,且混流涡轮性能随着负荷变化的趋势更为平缓,全工况下效率变化范围较径流叶轮下降30%~50%.损失分布研究表明,混流涡轮在叶尖附近区域损失较径流叶轮下降约60%.流动机理分析表明,不同负荷下混流叶轮的气流角分布更为均匀,尤其是低负荷时叶尖附近的气流角较径流叶轮明显降低,叶尖泄漏涡的尺寸和造成的损失大幅下降,因而混流涡轮的低负荷涡轮性能明显改善,变工况适应性有效提高.Aiming at the problem that the efficient operation range of radial turbines is relatively narrow and can not meet the requirements of wide and efficient operation range of turbines when the engine is running at variable altitude,the performance discrepancy and flow loss mechanism between a radial turbine and a mixed-flow turbine with the same swallowing capacity were studied via experimental and numerical methods.Results show that the efficiency of the mixed-flow turbine is 4.5%higher than that of the radial turbine under all turbine loads,although swallowing capacity of the two turbines is quite similar.In addition,the boundary of turbine efficiency for the mixed-flow turbine is 30%—50%narrower than that of the radial turbine,hence turbine performance of the mixed-flow turbine is less sensitive over operation conditions than that of the radial turbine,which indicates that the mixed-flow turbine has stronger off-design load adaptability.Results of loss distribution analysis illustrate that the loss in the shroud passage,tip passage and exit tip part is about 60%lower in the mixed-flow rotor than that in the radial turbine.Flow analysis of the two turbines indicates that the distribution of flow angle at the inlet of mixed-flow rotor is more uniform with the variation of turbine load than that of the radial rotor.Especially,the incidence angle near the tip of the leading edge of the radial rotor is higher than that of the mixed-flow turbine.As a result,the scale of tip leakage flow is shrunk in the mixed-flow turbine and leads to a lower loss in this region.Thus,the flow field in the mixedflow rotor passage is well improved,and hence the loss is lower and the turbine performance is well improved.

关 键 词：径流涡轮 混流涡轮 损失分析 性能 流动机理 

分 类 号：TK413.5[动力工程及工程热物理—动力机械及工程]