跨音压气机机匣处理扩稳机理和设计方法研究

发布时间：2019-03-01 09:49

【摘要】：压气机旋转失速等流动失稳现象限制了航空发动机的稳定工作范围。压气机失速的形成和叶顶区域的流动具有密切的关系。作为一种被动流动控制方法,机匣处理能够有效改善叶顶区域的流场,提高压气机的失速裕度。对于跨音压气机,机匣处理和叶顶泄漏涡、激波、边界层分离之间的相互作用使叶顶流场极为复杂。目前,机匣处理的扩稳机理和高效设计方法仍是跨音压气机研究领域的热点问题。本文针对目前跨音压气机机匣处理研究方面需要进一步完善的问题开展了研究工作,研究内容包括：1.基于人工神经网络代理模型对跨音压气机周向槽机匣处理进行了多目标优化设计,获得了能够兼顾失速裕度和峰值效率的周向槽机匣处理方案,并通过对比模型预测结果和数值计算结果验证了该方法可靠性。进一步通过分析周向槽和叶顶流场之间的相互作用,研究了优化后的机匣处理方案对压气机性能的影响机理。2.通过正交试验和极差分析方法对周向槽深、叶顶间隙和叶顶叶型安装角对跨音压气机失速裕度和峰值效率的影响进行了综合评估,得到了各设计变量的最优取值和各设计变量影响压气机性能的主次顺序,并对比分析了失速裕度最优方案和峰值效率最优方案对压气机叶顶流场和性能的影响。3.通过控制体方法对设计转速和60%设计转速下跨音压气机周向槽机匣处理的扩稳机理进行了定量分析。根据周向槽对控制体所受轴向力沿轴向分布的影响,对不同轴向位置周向槽的扩稳作用进行了评估。在此基础上,筛选出了扩稳作用较大的周向槽,并对移除了扩稳作用较小的周向槽的机匣处理方案进行了分析,发现机匣处理的扩稳效果并未因移除扩稳作用较小的周向槽而发生显著改变,验证了该分析方法的合理性。4.通过非定常数值模拟研究了周向槽单槽轴向位置变化对压气机稳定工作范围和叶顶流场非定常性的影响规律,并分析了周向槽控制叶顶非定常波动的机理。结果表明,位于叶顶中前部的周向槽能够有效降低叶顶泄漏流和主流的轴向动量比,并减弱叶顶泄漏涡引起的低压区和堵塞对叶顶载荷的影响,使叶顶流场的非定常波动得到明显抑制,扩稳效果较好。5.研究了轴向倾斜缝机匣处理轴向位置对跨音压气机性能的影响。通过相对权重法得出影响轴向倾斜缝扩稳效果的各因素的相对重要性排序为：缝内回流强度、叶顶载荷、叶顶进口轴向速度。研究表明,缝的上游端覆盖泄漏涡起始位置并且下游端覆盖激波后吸力面边界层分离区域,缝上游端和下游端之间的压差较大,缝内回流强度较大,能够有效地缓解叶顶泄漏涡和吸力面边界层分离引起的堵塞,有利于提高压气机的失速裕度。
[Abstract]:The steady operating range of the aeroengine is limited by the flow instability such as the rotary stall of the compressor. The formation of the compressor stall and the flow of the tip region have a close relationship. As a passive flow control method, the case treatment can effectively improve the flow field of the blade top area and improve the stall margin of the compressor. For transonic compressor, casing treatment and blade top leakage vortex, shock wave and boundary layer separation, the flow field of the blade tip is very complicated. At present, the expansion mechanism and high efficiency design method of casing treatment are still hot issues in the research field of transonic compressor. In this paper, the research work is carried out on the problems that need to be further improved in the research of the case processing of the transonic compressor case. The research contents include:1. The multi-objective optimization design of the circumferential groove casing treatment of the transonic compressor is carried out on the basis of the artificial neural network proxy model, and the circumferential groove casing treatment scheme which can balance the stall margin and the peak efficiency is obtained, And the reliability of the method is verified through the comparison model prediction result and the numerical result calculation result. The effect of the optimized casing treatment scheme on the performance of the compressor is also studied by analyzing the interaction between the circumferential groove and the blade top flow field. By means of the orthogonal test and the range analysis method, the influence of the circumferential groove depth, the blade top clearance and the blade tip type installation angle on the stall margin and the peak efficiency of the transonic compressor is comprehensively evaluated, and the optimal value of each design variable and the primary and secondary sequence of each design variable affecting the performance of the compressor are obtained, The effect of the optimal scheme of stall margin and peak efficiency on the flow field and performance of the compressor blade is compared and analyzed. The stability mechanism of the circumferential groove casing treatment of the transonic compressor at the design speed and the design speed of 60% is analyzed quantitatively by the control method. According to the influence of the axial force of the circumferential groove on the axial distribution of the control body, the stability of the circumferential groove in different axial positions is evaluated. On the basis of this, the circumferential groove with the larger stabilizing effect is selected, and the case processing scheme of the circumferential groove with the small expansion stability is analyzed, and it is found that the stabilization effect of the casing treatment is not changed significantly by removing the circumferential groove with smaller expansion stability, The rationality of the analysis method is verified. The effect of the axial position change of the circumferential groove on the steady working range of the compressor and the unsteady performance of the blade top flow field is studied by unsteady numerical simulation, and the mechanism of the unsteady fluctuation of the blade top in the circumferential groove is analyzed. The results show that the circumferential groove located in the front of the blade tip can effectively reduce the axial momentum ratio of the tip leakage flow and the main flow, and reduce the influence of the low pressure area and the blockage on the blade top load caused by the tip leakage vortex, so that the unsteady fluctuation of the blade top flow field is obviously restrained, and the stabilizing effect is good. The effect of axial position on the performance of transonic compressor is studied. The relative importance of the factors which influence the stability of the axial inclined joint is obtained by the relative weight method. The relative importance ranking of the factors is as follows: the internal reflux strength, the blade top load and the blade top inlet axial speed. the research shows that the upstream end of the slit covers the initial position of the leakage vortex and the downstream end covers the boundary layer separation area of the suction surface after the shock wave, Can effectively relieve the blockage caused by the separation of the blade top leakage vortex and the suction surface boundary layer, and is favorable for improving the stall margin of the compressor.
【学位授予单位】：中国科学院研究生院(工程热物理研究所)
【学位级别】：博士
【学位授予年份】：2015
【分类号】：V233

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