轴流压气机转子新叶型设计与试验研究

为进一步发展高性能轴流式叶轮机械叶片定制技术,本文提出了一种适于跨音速范围应用的轴流压气机转子叶型数值优化设计方法。并应用该系统对进口马赫数０．９１８的转子叶栅进行了设计及气动性能分析,通过与国外设计的同类叶栅的设计结果及风洞实验结果进行比较,验证了本文所用方法的有效性及精度。对比研究表明：采用本方法设计的叶栅具有低损失,宽稳定工作范围等优点。该项技术有良好的工程应用前景     

轴流式压气机叶列非设计工况沿径向气动参数的计算

本文提供了一个计算轴流式压气机叶列的非设计工况沿径气动参数的方法。用此方法对某台多级轴流式压气机的前两级和另一台单级试验压气机进行了计算。计算结果和试验的某些结果比较是令人满意的。该法对调试轴流式压气机可有一定的指导意义。     

叶轮机不均匀导向叶栅及其尾迹对转子叶片的激振研究

在轴流式压气机和涡轮中,不均匀导向叶栅及其尾迹将引起栅后流场速度和总压的周向畸变,并对其后的转子叶片产生周期性激振。本文分析了多种不均匀叶栅及其尾迹引起叶片振动的机理,并推导了计算叶栅尾迹、气体激振力以及叶片振动响应的计算方法。最后,对几种具体的不均匀叶栅进行了计算,并与相应的均匀叶栅进行了比较。结果表明:不均匀导流叶栅及其尾迹所引起的流场周向畸变,不仅使气体激振力频带变宽,而且还可能产生幅值很大的低阶倍频谐振力,并导致转子叶片疲劳破坏。     

叶片周向弯曲角度对扩压叶栅气动性能的影响

为了改善扩压叶栅气动性能,采用拟压缩性方法对不同周向弯曲角度的正弯曲叶片压气机叶栅内三维粘性流场进行了数值模拟.结果表明,随着弯曲角度的增加,端部流动状况逐渐得到改善,叶栅中部流动损失逐渐增加.正弯20°时可基本控制端部扩压因子至0.6以下.叶片弯曲角度的选择应以能满足设定目标的最小角度为最佳,过大的角度将会导致动静叶间匹配困难和较大的吸力面尾缘回流区     

高负荷氦气压气机矩形叶栅流动分离特性

针对高负荷氦气压气机叶栅流动分离问题,以某高负荷氦气矩形叶栅为研究对象,采用SST湍流模型加γ-Reθ转捩模型进行了数值模拟。分析了不同负荷、弯角及弯高的高负荷氦气压气机矩形叶栅的流动分离结构和特性。研究结果表明,马蹄涡压力面分支是矩形叶栅角区集中脱落涡和壁角涡形成的主要原因;随着攻角和负荷的增加,叶栅吸力面的分离形式由开式分离向闭式分离转化;而采用恰当的弯高和弯角可以有效抑制流动分离,改善高负荷氦气压气机端部流动状况,减小流动损失。     

弯叶片压气机叶栅在不同进口附面层厚度下的特性研究

采用人工加厚叶栅进口附面层厚度的方法,研究了弯叶片压气机叶栅在不同叶栅进口附面层厚度条件下叶栅特性的变化,实验结果表明,叶栅进口附面层厚度增加时,叶栅两端区二次流损失增加,近端壁气流的过转程度加强,正弯曲叶栅中低能流体向叶栅中部的迁移能力降低２。反弯曲叶栅中角区分离加剧。叶栅出口气流角和叶栅扩压能力和叶栅进口附面层厚工密切相关。     

反推力装置叶栅布置的气动/结构耦合设计

为了对叶片布置方案进行改进,采用耦合设计方法对反推力装置的气动性能和结构性能进行预测.利用计算流体力学（CFD）方法模拟装置流场,完成叶片布置方案的气动性能评估;利用有限元分析（FEA）方法分析叶栅叶片的受力情况,完成叶片布置方案结构性能的数值模拟.研究了叶栅进气角和出气角对反推效率的影响以及不同叶栅通道数目和叶片加强梁数目对反推装置气动性能和结构性能的影响.研究结果表明,叶栅进气角对反推效率影响不大,减小叶栅出气角可以增大反推效率;减少叶栅通道的数目会造成反推效率的下降,但可以减少叶片数目;减少加强梁的数目会使反推效率提高,降低装置的重量,但会增加叶片的最大应力和最大变形值.     

高速铣床主轴驱动透平叶栅设计与数值模拟

为使高精密数控铣床的主轴转速达到160000r/min,刀头切削力矩小于0.005N·m,针对驱动摆角铣头主轴的透平式气马达叶栅进行了气动力计算和平面造型设计,利用Fluent软件对其气动特性进行了数值模拟,并与理论计算对比验证模拟的正确性.研究叶栅气动特性随进气角、叶片数和叶高变化的规律,获得了使叶栅气动性能最佳的参数组合,即进气角为21°,叶片数为36,叶片高度为3.5mm时,叶栅的气动性能最佳。     

轴向密流比对叶栅性能影响的研究

轴向密流比是决定叶轮机械叶栅流动工作状态的一个重要参数,它对叶栅诸性能有较大的影响。本文对该问题进行了一些理论及实验方面的研究,推导出了叶栅总压损失系数、尾迹附面层特性参数、叶栅增压比及扩散因子等叶栅性能参数与轴向密流比的关联方程,并对某压气机叶栅进行了吹风实验,得到了不同轴向密流比条件下的叶栅性能。理论计算与实验结果进行了比较,两者的吻合程度是令人满意的,表明本文所得出的理论关联式可以有效地估算轴向密流比对叶栅性能的影响,具有一定的实用价值。     

高温气冷堆HTGR-10能量转换单元中压气机气动性能试验研究

氦气轴流式压气机作为高温气冷堆能量转换单元的关键部件之一,其性能直接影响系统的发电性能.HTGR-10采用Brayton直接循环系统进行能量转换,它的特点是透平压气机与系统的其他设备密封于同一单元内,保证了良好的安全性.对于系统整体设计来说,准确地估算压气机气动性能,稳定性边界和运行性能是很重要的,因此针对HTGR-10氦压气机的设计方案,建立了完整的实验装置系统,并且在不同操作压力、转速下分别得到了氦气和空气作为工质时的压气机特性曲线.最后,对于用空气代替氦气作为工质进行实验做了对比分析,研究了通过相似模拟方法用压气机的空气实验数据设计氦气压气机可行性和有效性.对比试验结果表明相似模拟的准确性很高.     

Prediction of stall inception in multi-stage compressors based on an eigenvalue approach

A stability model for multi-stage compressor is developed on the basis of the eigenvalue approach.This model assumes that the unsteady flow field can be decomposed into pressure,vortex and entropy waves.Besides,a linear cascade of blades is modeled by three-dimensional semi-actuator disk theory and the characteristics of steady flow field are also considered in the present model.The connection between the analytical solution for stator,rotor and gap can be established by applying mode matching approach,the relevant stability equation can be expressed in the form of matrix,while the compressor system stability can be judged by the imaginary part of the matrix eigenvalue.The capacity of the stall inception model to predict the stall inception point of multi-stage compressor is assessed against the experimental data of National Aeronautics and Space Administration(NASA) two stage fan.The theoretical results show that this model can predict the stall onset points of a two-stage fan at different operating speeds with a reasonable accuracy.     

Control of endwall secondary flow in a compressor cascade with dielectric barrier discharge plasma actuation

Three dielectric barrier discharge plasma actuators were mounted at the positions of 20%, 40% and 60% of chord length on the endwall in a compressor cascade. The downstream flow field of the cascade has been measured with a mini five-hole pressure probe with and without the plasma actuation. The measured results show that the plasma actuation most effectively reduces total pressure loss and flow blockage when the actuators are operated simultaneously. As each of the actuators is operated independently, the actuator at the position of 20% of chord length most effectively reduces flow blockage, and the actuator at the position of 60% of chord length fairly reduces total pressure loss. However, negative pressure loss reduction occurs with the plasma actuator at the position of 40% of chord length. In brief, the plasma actuation placed on the endwall in the cascade apparently influences the endwall secondary flow, and the optimal locations and strength of actuation are critical for the control of endwall secondary flow in a compressor cascade with the plasma actuators.     

叶栅端壁附面层叶片力亏损预测模型

本文基于实验结果,提出了一种预测轴流压气机叶栅端壁附面层叶片力亏损的通用模型.该模型的理论性强、物理意义明确.它包含了目前广泛使用的现有诸种叶片力亏损模型且明显减少了模型的经验性.应用于不同轴流压气机叶栅端壁附面层流动的数值分析结果与实验结果的比较表明,本文所建立的新模型通用性更强且精度也得到了进一步的提高.     

叶表和端壁抽吸对跨音速压气机稳定性影响对比分析

以NASA Rotor35为研究对象,应用数值模拟手段深入分析了叶表和端壁不同位置抽吸对该压气机稳定性的影响效应。研究结果表明:叶表抽吸虽然使得压气机压比和效率有所升高,但使叶顶前缘脱体激波和间隙泄漏流强度的增加,导致两者相互作用引起的低能堵塞团尺度过早增长,压气机提前进入失速;端壁抽吸改善了转子顶部前缘激波结构,削弱了叶顶低能阻塞团中的高熵流体,改善了叶顶区域的流动,实现了压气机的扩稳效果,但对压气机压比和效率性能改善不明显。     

变马赫数下压力面小翼对扩压叶栅气动特性的影响

为探究变来流马赫数下压力面叶尖小翼对扩压叶栅气动特性的影响,对Ma=0.5、Ma=0.6和Ma=0.7来流马赫数下的原型叶栅和加装不同宽度的压力面叶尖小翼的扩压叶栅流场特性进行了实验研究. 结果表明:在高亚声速的来流条件下,压力面叶尖小翼可以有效减小叶顶两侧压力梯度,阻碍流体流入叶顶间隙,控制叶顶泄漏流动,减小流场损失,改善流场流动状况. 随着小翼宽度的增加,改善程度增大,同时马赫数的变化与控制效果成正比. 当Ma=0.7时,与原型叶栅相比,PW2.0方案的流场改善程度最大,总压损失系数降低了6.53%.     

Aerodynamic performance of high-turning curved compressor cascade with boundary layer suction

The impact of boundary layer suction on the aerodynamic performance of a high-turning compressor cascade was numerically simulated and discussed.The aerodynamic performance of a curved and a straight cascade with and without boundary layer suction were comparatively studied at several suction flow rates.The results showed that boundary layer suction dramatically improved the flow behavior within the flow passage.Moreover,higher loading over the whole blade height,lower total pressure loss,and higher passage throughflow were achieved with a relatively small amount of boundary layer removal.The integration of curved blade and boundary layer suction contributed to better aerodynamic performance than the cascades with only curved blade or boundary layer suction used,and the more favorable effect resulted from the weakening of the three dimensional effects of the boundary layer close to the endwalls.     

Aerodynamic performance of high-turning curved cascade with boundary layer suction

The impact of boundary layer suction on the aerodynamic performance of a high-turning compressor cascade was numerically simulated and discussed. The aerodynamic performance of a curved and a straight cascade with and without boundary layer suction were comparatively studied at several suction flow rates. The results showed that boundary layer suction dramatically improved the flow behavior within the flow passage. Moreover, higher loading over the whole blade height, lower total pressure loss, and higher passage throughflow were achieved with a relatively small amount of boundary layer removal. The integration of curved blade and boundary layer suction contributed to better aerodynamic performance than the cascades with only curved blade or boundary layer suction used, and the more favorable effect resulted from the weakening of the three dimensional effects of the boundary layer close to the endwalls.     

高空低雷诺数二维抗分离叶型研究

在高空、低速、低雷诺数下,进行具有较强抗分离能力的新叶型研究,探索叶型设计的新概念和新方法,并发展相应的低雷诺数压气机叶片二维设计技术是十分关键的。文中进行了低雷诺数条件下二维压气机叶栅流场计算与对比,在探索高空、低速、低雷诺数对压气机叶型性能影响的基础上,以发展适应低雷诺数流动,具有较强抗分离能力的新叶型为最终目标,进行叶型设计新理论和新方法的探索,为最终突破低雷诺数下叶型设计的关键技术提供了可行的途径,并为三维叶片优化造型打下了基础。