微型离心压气机转静子间隙对级性能影响研究

发布时间：2018-01-20 07:20

本文关键词： 微型离心压气机流动机理数值模拟非稳态转静子间隙　出处：《南京航空航天大学》2014年硕士论文　论文类型：学位论文

【摘要】：微型离心压气机具有单级增压比高、构造简单、轴向长度小的优点，军、民用前景广阔。正确认识转静子间隙对压气机内部流动的影响对提高离心压气机整级性能具有重大意义。因此，本文采用数值模拟的方法对转静子间隙对离心压气机的影响规律进行了研究，主要有以下方面： 1、开展了对离心压气机内部流动的机理分析，分析了离心叶轮内部流场结构，找到了主要损失源。研究了叶轮内部激波、泄漏涡、通道涡、“射流-尾迹”结构以及扩压器进口周期性的非均匀分布产生的原因及影响。 2、对叶轮匹配有/无转弯段的两种无叶扩压器及有叶扩压器的状态下叶轮的性能及流场进行对比，总结了叶片扩压器对叶轮性能的影响机理。叶轮匹配两种无叶扩压器后性能接近，匹配有叶扩压器后，叶轮压比、效率、做功能力均有所下降，叶轮出口分离涡沿流向的位置前移。初步确定了扩压器叶片对叶轮出口参数分布的影响规律，对叶轮内部的影响范围覆盖了20%子午弦长的叶片后段。 3、对离心叶轮匹配有叶扩压器时采用了非稳态计算，确定了叶轮叶片与扩压器叶片不同相对位置时压气机内部流动的变化规律，研究了扩压器进口的周期性非均匀分布对叶轮出口周向及展向参数分布的周期性影响。 4、对转静子间隙内部流动进行了机理性研究分析，对比了不同转静子间隙下，叶轮以及整级的性能参数的不同，选取三个不同间隙方案进行流场分析并且对性能参数的不同进行了解释说明。初步确定了转静子间隙对离心压气机的影响规律，肯定了对于离心压气机最佳转静子间隙的存在，对于本文研究对象，在限定扩压器最大直径及出口几何参数不变的条件下，最佳转静子间隙为r3/r2=1.08。
[Abstract]:Miniature centrifugal compressor has the advantages of high single-stage booster ratio, simple structure and small axial length. It is of great significance to correctly understand the influence of rotor clearance on the internal flow of compressor to improve the integral performance of centrifugal compressor. In this paper, the influence of rotor clearance on centrifugal compressor is studied by means of numerical simulation. 1. The internal flow mechanism of centrifugal compressor is analyzed, the structure of flow field in centrifugal impeller is analyzed, the main loss source is found, and the shock wave, leakage vortex and channel vortex in impeller are studied. The causes and effects of the "jet wake" structure and the periodic non-uniform distribution of diffuser inlet. 2. The performance and flow field of impeller are compared under the condition of impeller matching two kinds of vaneless diffuser with or without turning section and the condition of vaned diffuser. The influence mechanism of blade diffuser on impeller performance is summarized. The performance of impeller matching two kinds of vaneless diffuser is similar, and the impeller pressure ratio, efficiency and work ability are decreased after matching blade diffuser. The influence of diffuser blades on the distribution of impeller outlet parameters is preliminarily determined, and the influence range on the impeller interior covers the rear segment of the blade with 20% meridional chord length. 3. The unsteady calculation of centrifugal impeller matching vaned diffuser is adopted, and the variation law of compressor internal flow is determined when the impeller blade and diffuser blade are in different relative positions. The influence of periodic non-uniform distribution of diffuser inlet on the circumferential and spanwise distribution of impeller outlet is studied. 4. The mechanism of the internal flow in the stator clearance is studied and analyzed, and the performance parameters of the impeller and the whole stage are compared under different rotor clearances. Three different clearance schemes were selected to analyze the flow field and the different performance parameters were explained. The influence of rotor clearance on centrifugal compressor was preliminarily determined. The existence of optimal rotor clearance for centrifugal compressor is confirmed. For the research object of this paper, the maximum diameter of diffuser and the geometric parameters of outlet are not changed. The optimal transposon gap is r _ 3 / r _ 2N _ (1.08).
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TH452

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