Concept of monitoring for thermostressed state and service life of aircraft gas turbine engine blades

A concept of monitoring for material properties with residual life estimation of rotor blades for gas turbine engines is proposed. The structure of on-board control and conditionmonitoring system based on the intelligent pyrometer module with the algorithm for calculating the residual life of turbine rotor blades is described.     

高温合金涡轮叶片材料的现状与发展

 本文回顾了自1956年以来,近三十年我国航空发动机铸造涡轮叶片的发展历史和现状,归纳了在此期间材料和铸造科研人员提供的铸造高温合金和铸造方法,满足了航空发动机的需要。 在铸造动叶片、空心叶片的陶瓷型芯、弥散强化合金的研究与运用计算机进行质量控制等方面都取得显著的成就。 着眼为将来发展高性能发动机,文中提出研究陶瓷和难熔金属材料以适应下列要求: 1.更高的工作温度 2.更高的表面稳定性 3.更高的力学性能 除了应不怕失败地发展上述材料外,还应考虑高温合金仍是550～1100℃下工作的发动机结构件材料,而且还要使用一段很长的时间。因此,要研究推广计算机的应用。难熔金属模具及真空压铸叶片工艺的改进,将提高叶片质量和代替传统的熔模铸造工艺。     

带密布气膜冷却孔的涡轮叶片等效应力分析方法研究

以带气膜冷却孔的航空燃气涡轮发动机涡轮叶片为研究背景,引入了等效概念对密布小孔结构进行了详细的应力-应变分析。这种等效分析方法是把多孔材料转化为具有等效材料常数的等效实体材料。根据MARC大型通用软件的线弹性及弹-塑性有限元应力分析结果,将小孔效应转化为等效弹性常数及等效应力-应变曲线。最后以某发动机高压涡轮工作叶片为例,将得到的等效材料参数引入到叶片的有限元强度计算中,从而得到考虑密布孔影响的涡轮叶片应力应变场,并通过子模型计算得到更为准确的孔边最大应力。     

Stress concentration in compressor blades at their damage by foreign objects

In this paper, the theoretical studies of stress concentrations in the compressor blades of aircraft gas turbine engines damaged due to foreign objects ingestion into the gas-air flow path are presented. The technique of three-dimensional finite-element calculations of the theoretical stress concentration factor in the damage region has been developed. We also examined the influence of geometrical blade parameters and damages (stress concentrators) upon the theoretical concentration factor and suggest using a simple relation for its approximate assessment.     

涡轮叶片疲劳寿命公式及可靠性预测方法

本文推导了液体火箭发动机涡轮叶片疲劳寿命公式,并用概率统计、断裂力学方法,分析了可靠性预测方法.     

舰载全电推进系统智能燃气轮机的关键技术及发展展望

随着对性能、运行安全和节能减排的日益重视,对燃气涡轮发动机的设计要求越来越高。在过去的10年中,智能燃气涡轮发动机由于可以兼顾性能及可靠性而越发受到重视。通过提炼智能燃气涡轮发动机的收益及挑战,系统回顾了智能燃气涡轮发动机涵盖的技术领域及需求。通过与航空发动机及地面燃气轮机的典型任务剖面差异进行对比,提出针对舰载燃气涡轮发动机智能化特色需求。在此基础上,梳理出进气畸变实时监测及畸变指数评估、压缩系统喘振预警及叶片振动监测、高压涡轮自适应热管理和高温旋转件叶尖间隙测试4项关键技术。重点讨论了每项关键技术带来的收益、国内外研究现状及实施这些技术所面临的挑战。然而,上述关键技术的落地仍需从单一技术的成熟及完善、多维度的技术收益论证2个层次持续开展相关工作。     

航空发动机涡轮盘榫齿裂纹故障研究

B型机由A型机改型而成,大批服役期中的A型机存在着大量Ⅱ级盘(简称为盘)第一榫齿裂纹与掉块故障。其轻者,裂纹超过标准后报废;重者,榫齿掉块,打伤其它零件,甚至叶片飞出(简称脱榫)。经过故障件金相检查,断口分析,其裂纹性质属机械疲劳。在疲劳损伤中,叶片类零件主要是高循环疲劳。为排除B型机盘和叶片榫齿间连接的故障,我们研究了在飞行与试车台上A、B型机Ⅱ级涡轮叶片(简称为叶片)的振动情况。      

基于卡尔曼滤波器及神经网络的发动机故障诊断

提出了一种基于卡尔曼滤波器及神经网络的航空燃气涡轮发动机气路故障诊断的方法.该方法用卡尔曼滤波器来估计发动机可测参数的变化量,再由神经网络来映射发动机性能参数的变化量,并据此进行发动机气路故障诊断.数字仿真表明,该方法是可行的,有效的.      

燃气涡轮发动机的状态监控与故障诊断

 为了提高燃气涡轮发动机的可靠性,耐久性并降低直接使用成本,近年来发展了发动机状态监控与故障诊断系统。大量试验和使用经验证明了这个系统的有效性。目前,该系统已在航空燃气轮机,工业燃气轮机和车辆用燃气轮机上广泛应用。 本文介绍了这个系统的功能,技术要求,并着重介绍了用气动热力参数,振动和滑油分析进行状态监控及故障诊断的原理及其应用。最后,文章讨论了今后发展中的问题。     

具有弯扭叶片的燃气透平正问题计算方法

本文开发了一个实用的多级燃气透平S₂流面跨音正问题的计算程序,用它对一台燃气透平的改型设计进行了计算。通过计算研究了弯扭叶片在透平改型设计中应用的可能性;分析了不同的叶片弯曲方法给透平性能带来的影响;提出了对弯扭叶片的气动设计具有指导意义的意见。      

辐射测温技术在涡轮叶片温度场中的应用

本文利用辐射高温计ROTAMAPII测量了某型燃机二级涡轮转子叶片的发射率。通过对该燃机的试车获取了多个试验状态的数据．对试验状态9100r／min、2260kW下的试验数据进行分析表明,该燃机涡轮叶片温度场与理论要求是吻合的。     

高超声速飞行与TBCC方案简介

介绍了TBCC(燃气涡轮发动机为基础的联合(组合)循环)方案,以及以TBCC发动机为动力装置的高超声速攻击机方案。     

Theory of an annular corrugated damper in the vibrator precession motion

The theory for calculating elastodamping characteristics of multilayer corrugated dampers being used in the rotor supports of aircraft gas turbine engines (GTEs), turbo-pump assemblies of rocket engines as well as in different articles of machine building industry is presented.     

基于显微组织演变的涡轮叶片损伤分析

涡轮叶片作为航空发动机和燃气轮机重要的热端部件,在复杂温度场、应力场及氧化腐蚀等环境下工作,面临多种损伤失效风险。为了阐明涡轮叶片涂层损伤模式,总结了现阶段涡轮叶片涂层工艺、特点及其显微组织构成。在结合叶片材料热力耦合试验中相的演变规律研究成果基础上,对服役不同时间和类型的涡轮叶片基体和涂层系统的显微组织进行分析,并与原始组织对比;确定了各种服役组织损伤形式,主要包括涂层系统退化、原始缺陷导致的裂纹扩展、过热损伤及γ′相的退化等;初步给出了涡轮叶片损伤机理和服役环境评估,提出后期涡轮叶片工程化应开展的研究工作和注意事项,从而实现由服役叶片失效后分析向使用前预防的转变,完善涡轮叶片正向设计体系。     

Hardware-in-the-loop testing technology for integrated control and condition monitoring systems of aircraft gas turbine engines

Hardware-in-the-loop testing technology for automatic control, condition monitoring and diagnostics systems of gas turbine engines is described. The technology proposed makes it possible to simulate combinations and chains of unexpected and gradual failures of engines, transducers and actuators.     

微型涡喷发动机顶层设计研究

对微型涡轮喷气发动机的顶层设计问题进行了研究。首先分析了发动机尺寸对性能的影响,揭示了微型发动机推重比具有与尺寸成反比提高的潜力。基于各相关学科近期能达到的技术水平,选择了微型发动机尺寸并提出了初步设计方案。对微型涡喷发动机的压比、燃烧室出口温度和各部件效率等设计参数进行了单变量和双变量分析,得到了这些参数对推力、耗油率等性能的影响规律。提出了一个能简便准确地判断微型发动机顶层设计方案是否能产生推力的判别准则,并得出了高、中、低性能的三种气动热力参数顶层设计方案。      

Modelling internal air systems ingas turbine engines

Rotating-disc systems can be used to model,experimentally and computationally,the flow and heat transfer that occur inside the internal cooling-air systems of gas turbine engines.These rotating-disc systems have been used successfully to simplify and understand some of the complex flows that occur in internal-air systems,and designers have used this insight to improve the cooling effectiveness,thereby increasing the engine efficiency and reducing the emissions.In this review paper,three important cases are considered:hot-gas ingress;the pre-swirl system;and buoyancy-induced flow.Ingress,or ingestion,occurs when hot gas from the mainstream gas path is ingested into the wheel-space between the turbine disc and its adjacent casing.Rim seals are fitted at the periphery of the system,and sealing flow is used to reduce or prevent ingress.However,too much sealing air reduces the engine efficiency,and too little can cause serious overheating,resulting in damage to the turbine rim and blade roots.Although the flow is three-dimensional and unsteady,there are encouraging signs that simple ‘orifice models’ could be used to estimate the amount of ingress into the wheel-space.In a pre-swirl system,the cooling air for the gas-turbine blades is swirled by stationary nozzles,and the air is delivered to the blades via receiver holes in the rotating turbine disc.Swirling the air reduces its temperature relative to the rotating blades,and the designer needs to calculate the air temperature and pressure drop in the system.The designer also needs to calculate the effect of this swirling flow on the heat transfer from the turbine disc to the air,as this has a significant effect on the temperature distribution and stresses in the disc.Recent experimental and computational studies have given a better understanding of the flow and heat transfer in these systems.Buoyancy-induced flow occurs in the cavity between two co-rotating compressor discs when the temperature of the discs is higher than that of the air in the cavity.Coriolis forces create cyclonic and anti-cyclonic circulation inside the cavity and,as such flows are three-dimensional and unsteady,the heat transfer from the discs to the air is difficult either to compute or to measure.The flow also tends to be unstable and one flow structure can change quasi-randomly to another,which makes it hard for designers of aero-engines to calculate the transient temperature changes and thermal stresses in the discs during take-off,cruise and landing conditions.Although recent CFD research has been successful in computing these flows,it will be many years before the designer can rely on computations unless they have been validated on reliable experimental data.      

某型燃气涡轮发动机风车状态内阻力的计算

由于很多燃气涡轮发动机都缺乏计算风车特性必需的低转速状态的部件特性，给计算发动机风车状态的特性带来了很大的困难。但是，风车特性是燃气涡轮发动机设计和使用过程中必须考虑的，因此，本文参考尤．阿．李特维诺夫提出的计算发动机风车特性的方法，计算了燃气涡轮发动机风车状态时的内阻力。从计算结果分析，该方法不依赖于部件特性，非常适合燃气涡轮发动机的风车特性计算。     

复合式气冷涡轮导叶冷却设计与试验

介绍了某型复合式气冷涡轮导叶的冷却设计与试验研究,在较高的温度和压力条件下,进行了真实叶片的冷却效果试验。通过对试验状态的对比计算及试验结果的分析,结果表明:所设计的涡轮复合式气冷导叶在较宽广的冷气流量比范围内,具有良好的冷却特性,计算结果与试验结果吻合较好。      

Optimization of cooling structures in gas turbines:A review

Attempts for higher output power and thermal efficiency of gas turbines make the inlet temperature of turbine to be far beyond the material melting temperature. Therefore, to protect the airfoil in gas turbine from hot gas and eventually prolong the lifetime of the blade, internal and film cooling structures with better thermal performance and cooling effectiveness are urgently needed.However, the traditional way of proceeding involves numerous simulations, additional experiments,and separate tr...