跨音速栅流场的数值模拟

论述了时间相关有限差分法在跨音速叶栅流动计算中的应用，并以具有代表性的跨音速压气机叶栅流场的计算和图样的制取为例，附以程序编制及其流程图，详细地讲解了计算程序的具体操作。由比较可以看出此方法较以前的时间推进法要快得多。可以预期，随着该方法的不断完善，得到更为精确的结果是完全有可能的。     

高负荷跨音速透平叶栅气水模拟的试验研究

本文介绍了在我国首次利用气水模拟方法对某高负荷跨音速透平动、静叶栅进行详尽的空气动力学试验研究的结果,并将结果与平面叶栅风洞试验及叶栅绳流的计算结果进行比较。气水模拟方法对跨音速叶栅的方案设计和定性分析具有正确、直观、简便、经济的优点。本方法不仅可替代繁重的平面叶栅高速风洞的试验工作,还可验证跨音速叶栅绕流的计算结果。     

设计透平跨音速叶栅时出气角的确定

本文综述了在设计透平跨音速叶栅时气流出气角的各种计算方法和相应的公式,并和试验结果进行了对比。文中还提供了收缩——扩张形流道的跨音速叶栅出气角计算时所用的曲线。     

计算跨音速透平叶栅极限进气角的方法

本文提出了一个计算跨音速透平叶栅的极限进气角的方法。该法以叶栅的相对极限环量为根据。用本法计算得到的极限进气角和实验结果吻合较好。     

跨音速压气机叶栅中稠度对弯掠叶栅流场影响的数值分析

将一跨音速静叶栅数值计算结果与实验结果进行了比较,结果表明计算与实验结果吻合较好。为了讨论跨音速压气机中弯掠叶片的适用条件,在0°攻角下,稠度为1.75、1.50和1.25,对0~30°弯掠叶流场进行了数值分析,结果表明大稠度弯掠叶片的效果较为明显。弯掠叶片使前缘激波转化为斜激波,并减弱了通道激波的强度,因而降低了叶栅激波损失。可以验证在跨音速条件下稠度的大小是否在静叶栅中使用弯叶片的一个重要的参考因素。     

跨音速透平叶栅极限进气角的确定

本文提供了一个计算大功率汽轮机末级动叶顶部截面跨音速叶栅的极限进气角的方法.按本方法求得的极限进气角与吹风试验及数值试验的结果吻合较好.     

跨音速透平叶片尾缘流动状态的试验研究

本文叙述了在跨音速风洞中模拟跨音速透平叶片尾缘流动的试验结果.分析了跨音速透平叶片尾缘流动的机理.说明了诸如附面层、叶片尾缘厚度、来流马赫数等因素对尾缘死水区基压的影响.提出通过改变尾缘形状来改善跨音速叶栅气动特性的途径.图8表1参15     

跨音速压气机中展弦比弯掠叶片气动性能影响的分析

将一跨音速静叶栅数值计算结果与实验结果进行了比较,表明计算与实验结果吻合的较好.为了讨论跨音速压气机中弯掠叶片适用的展弦比条件,在0°攻角下,展弦比为1.25、1.50和2.00,对0～30°弯掠叶片流场进行了数值分析,结果表明,当10°弯掠角时,小展弦比弯掠叶片对叶片性能影响较为明显;而在20°弯掠角时,大展弦比弯掠叶片对叶片性能影响较为明显.弯掠叶片使前缘激波转化为斜激波,并减弱了通道激波的强度,因而降低了叶栅激波损失.可以证明,在跨音速条件下展弦比的大小是如何使用弯掠叶片的一个重要的参考因素.     

某跨音速叶型的吸力面"凹"形设计

为了探索在超跨音速下具有优良启动特性的叶型,以某跨音速叶型为例,对吸力面作了“凹”形设计,分析比较了改型前后叶栅气动性能的变化,为叶型设计提供一种思路。     

跨音速涡轮叶栅叶型损失预测

利用中国科学院工程热物理研究所和哈尔滨汽轮机厂合建的暂冲式跨音速平面叶栅风洞,进行了3套跨音速涡轮叶栅吹风实验.在此基础上,结合近年发表的跨音速涡轮叶栅叶型损失数据,详细讨论了跨音速涡轮叶栅在设计和非设计两种工作状态下叶型损失的预测方法.在具体分析设计状态下Kacker&Okapuu损失估算模型的基础上,针对发生在进出口区域的激波损失,提出了工程上更为适用的激波损失计算方法,初步建立了跨音速涡轮叶栅在不同攻角状态下的叶型损失预测系统,为跨音速涡轮的工程设计提供了较为可靠的基础性支持.     

海豚叶型设计的初步尝试

为了探索在超跨音速下具有优良启动特性的叶型,以某跨音速叶型为例,初步尝试设计海豚叶型,并对其流场进行了数值模拟,以评估这种叶型是否适合于超跨音速流动。     

Aerodynamic Optimum Design of Transonic Turbine Cascades Using Genetic Algorithms

INTRoDUCTIoNInmodernturbomachinery,withtheincreasingstageload,thetransoniccascadesbecomemorewidelyused,sothedesignofhighperformancetransoniccas-cadesisacriticaJpracticalproblem.Performanceop-timizationofaerodynamicshapeplaysanimportantroleinthedesigntasksofttirbomachinery,andisanactiveresearchfield.Awidevarietyoftechniqueshavebeendeve1opedtofacethisprobleml1].FuIthermethodsbasedonartificialintelligence-expertsystemtechniqueshavealsobeenintroducedl2].Butthediffusionofauto-matedshapedesigni…     

用于跨声速叶轮性能计算的多种分裂格式的分析与比较

针对跨声速压气机叶片内复杂的三维流动,采用自行开发的三维CFD程序对跨音速轴流压气机NASA Rotor 37流场进行数值模拟,对比分析了L-F（Lax Friedrichs）、Steger Warming及Van Leer 3种通矢量分裂格式和AUSMDV混合格式在跨声速叶轮流场数值计算时的格式效应。研究表明：与其他格式相比,AUSMDV在设计工况下的计算结果与实验误差最小,对激波和叶顶间隙泄漏的捕捉能力最强,Van Leer格式次之;Steger Warming格式在计算过程中收敛性最好。     

Influence of Hub Contouring on the Performance of a Transonic Axial Compressor Stage with Low Hub-Tip Ratio

The rotor blade height with low hub-tip ratio is relatively longer,and the aerodynamic parameters change drastically from hub to tip.Especially the organization of flow field at hub becomes more difficult.This paper takes a transonic 1.5-stage axial compressor with low hub-tip ratio as the research object.The influence of four types of rotor hub contouring on the performance of transonic rotor and stage is explored through numerical simulation.The three-dimensional numerical simulation results show that different hub contourings have obvious influence on the flow field of transonic compressor rotor and stage,thus affecting the compressor performance.The detailed comparison is conducted at the rotor peak efficiency point for each hub contouring.Compared with the linear hub contouring,the concave hub contouring can improve the flow capacity,improve the rotor working capacity,and increase the flow rate.The flow field near blade root and efficiency of transonic rotor is improved.The convex hub contouring will reduce the mass flow rate,pressure ratio and efficiency of the transonic rotor.Full consideration should be given to the influence of stator flow field by hub contouring.     

A Study of 3D Aerodynamic Design for a Transonic Compressor Blading Optimized by the Locations of Aerofoil Maximum Thickness and Maximum Camber

A design procedure for improving the efficiency of a transonic compressor blading was proposed based on a rapid generation method for three-dimensional blade configuration and computational meshes, a three-dimensional Navier-Stokes solver and an optimization approach. The objective of the present paper is to design a transonic compressor blading optimized only by selection of the locations of maximum camber and maximum thickness for the airfoils at different span heights and to study how do these two design parameters affect the blade performance. The blading configuration and the computational meshes can be obtained very rapidly for any given combination of maximum camber and maximum thickness. The computational grid system generated is used for the Navier-Stokes solution to predict adiabatic efficiency, total pressure ratio and flow rate. As a main result of the optimization, adiabatic efficiency was successfully improved.     

跨音速涡轮叶片成型方法的研究发展

随着叶轮机械向高膨胀比、高效率的方向发展,叶轮机械级内部越来越多地出现跨音速流动现象。利用数值计算模拟叶轮机械内部的超、跨音速流动,降低激波损失和强度,对提高超、跨音速叶轮机械的性能具有重要意义。     

用工程方法考虑流动损失的跨音速透平级全三元流场的计算

介绍了用时间推进法计算有流动损失的跨音速透平级全三元流场的计算方法,流动损失采用哈尔滨汽轮机厂提供的损失模型进行计算。对考虑流动损失与忽略流动损失的全三元流场计算结果进行了对比,发现考虑流动损失后反力度有一定的提高,速度三角形也有少量变化,说明考虑流动损失对于进一步改进透平级设计是必要的。本文提供的方法可供工程设计应用。     

进口气流角对某跨音级叶栅影响的数值分析

以某型大流量轴流压气机跨音级叶栅为研究对象,采用三维数值模拟方法分析了进口气流角的变化对跨音级叶栅流量特性及内部流场的影响。结果表明,随着进口气流角的增大,跨音级叶栅流量-效率和流量-压比特性线都向流量减小的方向偏移,并且动叶栅中激波的位置和强度的变化直接决定了跨音级叶栅压比和效率的变化。     

Liquid phase evaporation on the normal shock wave in moist air transonic flows in nozzles

This paper presents a numerical analysis of the atmospheric air transonic flow through de Laval nozzles.By nature,atmospheric air always contains a certain amount of water vapor.The calculations were made using a Laval nozzle with a high expansion rate and a convergent-divergent (CD) "half-nozzle",referred to as a transonic diffuser,with a much slower expansion rate.The calculations were performed using an in-house CFD code.The computational model made it possible to simulate the formation of the liquid phase due to spontaneous condensation of water vapor contained in moist air.The transonic flow calculations also take account of the presence of a normal shock wave in the nozzle supersonic part to analyze the effect of the liquid phase evaporation.