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在实际轴流压气机加工、装配、使用过程中,机匣的圆度控制、叶片的高度控制、转子和机匣之间的同轴度控制等都普遍存在误差,意味着叶尖间隙的不均匀性必然地存在于每台压气机中。随着对轴流压气机流动研究的不断深入,叶尖周向非均匀间隙成为了需要考虑的问题。针对由机匣变形造成的非均匀叶尖间隙,研究了其对多排转子流场特性的影响。首先介绍了表征机匣变形程度的新参数,进而引进了非轴对称压气机模型的建模方法。针对3种不同的间隙周向布局,采用定常和非定常方法进行了数值模拟,对比了均匀与非均匀间隙下多排转子的气动性能,分析了机匣变形对气动损失分布和传播的影响,并研究了非均匀间隙下非定常压力和气动力的脉动特征。结果表明:非均匀间隙会降低转子性能,转子叶排叶尖区域的流场在非均匀间隙下呈现明显的周向非对称性,在上游叶排“尾迹”的干扰下,后排转子叶尖流场的周向非对称性要大于前排转子。非均匀间隙布局与各叶片气动力分布呈现明显的对应关系,小间隙区域叶片的气动力高,大间隙区域叶片气动力相对较低,从而增加了非均匀间隙下转子叶片的气动力幅值。
In the actual axial flow compressor machining, assembly, use, the casing of the roundness control, blade height control, the rotor and the control of the coaxiality between the casing and other common errors, which means that the tip clearance is not Uniformity necessarily exists in each compressor. As the research on axial flow compressor continues to deepen, non-uniform circumferential tip clearance becomes a problem to be considered. In view of the non-uniform tip clearance caused by the deformation of the casing, the influence of the multi-row rotor flow field characteristics is studied. First, a new parameter that characterizes the deformation of the receiver is introduced. Then a modeling method of the non-axisymmetric compressor model is introduced. In this paper, the numerical simulation of three kinds of circumferential gap layouts is carried out by using the steady and unsteady methods. The aerodynamic performance of multi-row rotors under uniform and non-uniform gaps is compared. The influence of casing deformation on the distribution and propagation of aerodynamic losses is analyzed. And studied the characteristics of unsteady pressure and aerodynamic pulsation under non-uniform gap. The results show that the non-uniform clearance reduces the rotor performance. The flow field in the tip region of the rotor blade shows obvious circumferential asymmetry under the non-uniform clearance. Under the interference of the upstream blade row, the back rotor tip Circumferential asymmetry of the flow field is greater than that of the front rotor. The non-uniform gap layout is obviously corresponding to the aerodynamic distribution of each blade. The aerodynamic force of the blade in the small gap area is relatively high, and the aerodynamic force of the blade in the large gap area is relatively low, which increases the aerodynamic amplitude of the rotor blade in the non-uniform gap.