叶轮出口结构形式对压气机性能及轴向载荷影响分析

发布时间：2018-04-23 10:18

本文选题：压气机 + 叶轮　；参考：《车用发动机》2016年01期

【摘要】：采用Numeca数值分析软件分析了3种不同出口结构形式的压气机叶轮性能,等出口大径情况下径流叶轮压比最高,斜流叶轮压比最低,效率方面则是半斜流叶轮最高。通过压气机流场分析发现,各转速小流量下,径流叶轮在叶轮出口轮缘一侧产生大范围的回流,斜流叶轮则在轮毂一侧产生较大范围的回流,而半斜流叶轮兼有径流叶轮和斜流叶轮设计特点,轮毂和轮缘两侧的流场均得到明显改善。在堵塞流量附近工况点,半斜流叶轮和斜流叶轮出口相对马赫数较径流叶轮略小,利于堵塞流量的增加。通过轴向载荷分析发现,由于斜流叶轮和半斜流叶轮相比等直径的径流叶轮压比较低,导致由压气机轮背指向压气机进口的轴向力减小,使得整个增压器转轴有向涡端运动的趋势,由此容易导致止推轴承压端磨损严重;与此同时,转轴移动也会使得叶轮与压气机蜗壳的轴向间隙增大,导致半斜流叶轮与斜流叶轮效率降低。
[Abstract]:The performance of three compressor impellers with different outlet structures was analyzed by Numeca software. The flow impeller pressure ratio is the highest, the inclined flow impeller pressure ratio is the lowest, and the efficiency is the highest in the case of equal outlet large diameter. Through the analysis of the compressor flow field, it is found that the flow impeller produces a large range of backflow on the side of the impeller outlet wheel, and a large range of reflux on the hub side of the inclined impeller under each rotating speed and small flow rate. The semi-oblique impeller has the characteristics of both the run-off impeller and the oblique impeller, and the flow field on both sides of the hub and rim is improved obviously. The relative Mach number at the outlet of semi-oblique impeller and oblique flow impeller is slightly smaller than that of runoff impeller at the working point near the clogging flow rate, which is beneficial to increase the clogging flow rate. Through the axial load analysis, it is found that the axial force from the back of the compressor to the inlet of the compressor is reduced because the pressure of the oblique impeller and the semi-oblique impeller is lower than that of the equal diameter flow impeller. The axial clearance between the impeller and the compressor volute will increase because of the tendency of the whole turbocharger shaft moving towards the vortex end, which will easily lead to serious wear on the thrust bearing end, and at the same time, the axial clearance between the impeller and the compressor volute will be enlarged. The efficiency of semi-oblique impeller and inclined impeller is reduced.
【作者单位】：湖南天雁机械有限责任公司;
【基金】：湖南省科技重大专项(2014FJ1013)
【分类号】：TK403

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