旋转进气畸变对压气机气动稳定性影响机理研究

发布时间：2018-04-18 21:13

本文选题：轴流压气机 + 气动稳定性　；参考：《南京航空航天大学》2015年硕士论文

【摘要】：压气机流动失稳现象的发生极大地限制了燃气涡轮发动机的工作范围,因此压气机的设计必须预留足够的稳定裕度以确保发动机工作时不发生失稳。然而,进气畸变的存在会使压气机更容易发生流动失稳,对于多轴发动机,如果上游压气机出现了旋转失速现象,那么下游压气机将工作在周向旋转的低压区的影响下,即旋转进气畸变。本文将探究旋转进气畸变对压气机稳定边界的影响规律,分析其影响机理。在M-G模型基础上发展的二维不可压缩模型可计算均匀、非均匀进气条件下轴流压缩系统的动态失速特性,本文在模型中加入了方波形式的旋转进气畸变流场,定量分析了不同畸变转速、畸变幅值和畸变角对压缩系统稳定性的影响。设计了一台可变畸变角的旋转进气畸变发生装置,在二级低速轴流压气机上开展了90°、30°、15°畸变角的各个畸变转速对压气机气动稳定性影响的实验。实验结果表明:旋转进气畸变的转速对压气机气动稳定性存在很大的影响,当畸变以某转速旋转时压气机的稳定裕度损失最大,称此转速为“危险转速”,并且此转速接近于完全发展的失速团传播速度。旋转进气畸变角的改变不会使“危险转速”产生变化,只是“危险转速”附近的边界点流量系数随着畸变角的减小而减小,而对其余转速下的边界点影响不大。结合模型计算和实验研究的结果,提出了旋转进气畸变对压气机稳定性影响机理的模型,该模型较好地解释了畸变以“危险转速”旋转时比其他转速下对压气机稳定性影响更大的原因。
[Abstract]:The phenomenon of compressor flow instability greatly limits the working range of gas turbine engine, so the compressor design must reserve enough stability margin to ensure that the engine does not lose stability.However, the presence of inlet distortion will make the compressor more prone to flow instability. For a multi-axle engine, if the upstream compressor has a rotating stall, the downstream compressor will work under the influence of the circumferential rotating low pressure region.That is, the rotation of the air intake distortion.In this paper, the influence of rotating inlet distortion on compressor stability boundary is studied and its influence mechanism is analyzed.The two-dimensional incompressible model developed on the basis of M-G model can calculate the dynamic stall characteristics of the axial flow compression system under uniform and inhomogeneous inlet conditions. In this paper, the distorted flow field in the form of square wave is added to the model.The effects of different distortion speed, distortion amplitude and distortion angle on the stability of compression system are quantitatively analyzed.A rotating air intake distortion generator with variable distortion angle was designed. Experiments were carried out on a two-stage low speed axial compressor with different distortion speeds of 90 掳to 30 掳and 15 掳distortion angle on the aerodynamic stability of the compressor.The experimental results show that the rotational speed of rotating inlet distortion has a great influence on the compressor aerodynamic stability. When the distortion occurs at a certain rotational speed, the compressor has the greatest loss of stability margin, which is called "dangerous speed".The speed is close to that of the fully developed stall group.The change of the distortion angle of the air inlet will not change the "dangerous speed", but the flow coefficient of the boundary point near the "dangerous speed" decreases with the decrease of the distortion angle, but has little effect on the boundary points at the other rotational speeds.Based on the results of model calculation and experimental study, a model of the influence mechanism of rotating inlet distortion on compressor stability is proposed.The model can explain why the distortion has more influence on the compressor stability when the distortion rotates at "dangerous speed" than at other rotational speeds.
【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】：2015
【分类号】：V235.1

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