【作者】 都昆；

【导师】 钟兢军；

【作者基本信息】 大连海事大学 ， 动力机械及工程， 2012， 硕士

【摘要】 压气机的性能和稳定性与进气畸变息息相关。如果无视进气畸变的影响,就会使压气机的气动性能恶化、效率和稳定裕度降低,甚至诱发旋转失速或喘振。因此,流场畸变的研究意义重大。本课题以某型高负荷超声速轴流压气机的一级为研究对象,应用全周非定常数值模拟的方法开展工作。重点研究设计工况下不同进口总压畸变条件时,动静叶栅内流场对畸变来流的响应机制。因为本文的研究对象为某型轴流式压气机一级的改型,其性能参数都较原型有所改变,所以就要重新绘制特性曲线。本文主要绘制90%、100%和110%设计转速下的压气机特性曲线,并采用Fluent和Numeca两种计算软件进行模拟,以便验证数值模拟结果的软件无关性。而后将数值模拟网格应用自适应功能加密,从总参数和关键截面内流场验证了网格无关性。本文对于非定常问题的研究均采用标记流道的方法,首先全面细致的探究了插板深度为进口外径(半径)38.2%的畸变类型。结果表明,畸变会使得压气机时均质量流量和等熵效率降低,并引起压气机可用稳定裕度的损失。通过对一个周期各时间步流场的研究,着重揭示了动静叶区域对于畸变来流的非定常响应。动叶区域,主要关注畸变影响下动叶流道中激波的结构、强度、位置的变化；静叶区域,重点分析畸变影响下静叶流道分离规律。并且从机理上探究了动静叶区域对于畸变响应的原因。对多种不同插板深度畸变的研究表明,随着插板深度的增加,压气机的时均质量流量和效率会随之下降。静叶的流动分离主要集中在叶顶和叶根处,静叶叶根处的分离会对叶顶分离产生抑制。当插板深度大于一定的程度后,进一步增加插板深度,只会使得动叶和静叶区域完全畸变区的流道数目增加(单纯范围上的扩大),而并不会加重单个流道的流动恶化程度。并且对于本文所研究的压气机来说,轮缘处的畸变更影响效率,而轮毂处的畸变更影响流量(即通流能力)。更多还原

【Abstract】 This paper is a presentation of a numerical simulation study on one stage axial flow compressor which is supersonic and high loaded. As the inlet distortion is closely related with the performance and the stability of compressor, it could deteriorate the aerodynamic performance of the compressor, decreases the efficiency and debases the stability margin,induse the appearance of rotating stall or surge. So the research of distortion have great significance. Applying the unsteady full-annulus simulation, the key point is how inner flow field of the rotor and stator response to the different inlet total pressure distortions in design condition.The object of study is the modification of one stage compressor. Therefore parameters are changed from the original one. So we need to redraw the characteristic curves. This paper mainly draw the characteristic curves under 90%,100%and110% of designed speed. These curves are simulated by Fluent and Numeca (two different softwares). Thus the results about software independence are proved. Employing the adaptive mesh refinement function to adapt the grid, the grid independence is proved from the general parameters and inner flow field of key sections.The marked single passage is used to investigate the unsteady simulation. First, the distortion that insert-board depth is 38.2% of inlet radius is deeply studied. The results are showed that the time averaged mass flow rate and efficiency of compressor are decreased, the available stability margin are reduced. Via the study of flow field in each time step of one period, the response mechanism between inlet distortion and inner flow field is emphatically revealed. In the rotor flow field, the variation of shock structure, intensity and position under effect of distortion is analyzed in detail; in the stator flow field, the separation law of stator end-wall is studied. What’s more the causation is explored profoundly.Via the studied about different deepness of insert-board distortions, indicated that with the increasing of the deepness, the time-averaged mass flow rate and efficiency of compressor are both decreased. The flow separation of stator mainly concentrate in the end-wall, the separation in stator hub will suppress the separation in casing area. Once the depth increased to definite value, the deeper insert-board reach, the more full development separation passages increase. But the degree of deterioration would not become more serious in those separation passages. To the compressor this paper studied, the distortion near the flange impacts the efficiency of the compressor closely,while that near the hub impacts the mass flow rate closely.更多还原