航空发动机应急放油功能失效故障分析

针对某型发动机在地面试车时发生的应急放油失效故障,通过分析故障现象、详细阐述应急放油系统工作原理及剖析故障机理,制定了排故流程。结合排故流程,列举应急放油附件电磁阀、电气系统、加力燃油泵故障3种故障原因,通过对3种故障原因逐条分析和排查,确定为加力燃油泵故障导致应急放油失效。更换加力燃油泵后进行试车验证,结果表明:发动机工作参数正常,应急放油功能正常,故障排除。总结得出类似加力燃油泵故障的快速判断方法,为后续故障的排除提供了新思路。     

某型航空发动机转速信号故障分析

某型航空发动机在地面台架试车的起动过程中,发生高压转子转速信号误报,造成起动失败;在外场装机地面试车时,在起动和停车过程中,发动机参数记录系统和EPI组合显示仪表显示出高压转子转速信号跳变。对发动机转速测量系统的工作过程进行分析,找到了该转速信号故障发生的原因,并提出了解决措施。     

某型航空发动机燃油系统供油异常故障研究

针对某型航空发动机燃油系统试车时出现供油异常故障．通过理论分析、数值仿真和试验验证的方法,对停车转换活门可调油嘴调整钉增加自锁功能并进行试验验证,解决了供油异常故障,保障燃油系统稳定安全工作。     

某型航空发动机台架控制系统设计研究

台架控制系统是航空发动机地面台架试车的重要影响因素之一.针对某型航空发动机地面试车台,从发动机台架电气系统和上位机监控系统2方面介绍了试车台台架控制系统,着重阐述了基于PLC的控制系统在方法上的改进.该系统简化了控制结构,节省了台架资源,增加了试验的安全性和可靠性,已在发动机试车中投入使用.系统运行稳定可靠,安全性高,具有广泛地应用价值.     

某型发动机滑油通风节流嘴流量-阻力特性试验研究

某型发动机后轴承腔采用了节流通风设计,通风腔节流嘴的阻力特性是发动机验证机试车选择首装节流嘴及后续调试的重要依据。对该型发动机可能使用的8种尺寸的节流嘴进行了阻力-流量特性试验,试验中模拟了发动机轴承腔中的油气混合流体介质。同时根据空气动力学原理,给出了估算发动机节流嘴壅塞状态下质量流量和体积流量的公式,并据此给出了在工程计算中初步估算所需节流嘴通径的方法。     

某型发动机地面试验台架超限保护防差错研究

针对某型发动机地面台架试验试车过程中出现超限故障,通过设置数采系统超限保护功能、台架/测功机应急燃油切断阀、增加测功机超限保护等方式,提高发动机超限保护功能,保证发动机试车安全,避免发动机工作超限。     

一起航空发动机主泵调节器进口燃油温度高故障分析

介绍了某型航空发动机燃油系统供回油系统的组成、加力燃油泵工作原理和应急放油附件工作原理,对主燃油泵调节器进口燃油温度高故障进行了理论分析,找出了故障原因,为排故提供了有益指导。     

某型航空发动机加力接通延迟故障分析

针对某型航空发动机加力接通延迟故障,根据发动机加力状态控制计划和调节规律,建立了以"加力接通延迟"为顶事件的故障树与故障处理流程图进行排故,有效提高了排故效率和试车合格率。     

某型发动机喷口收放故障分析与排除

针对某型发动机在地面试车时发动机进入最大状态后放喷口的一次意外故障,结合喷口调节系统的原理和调节过程,分析可能的故障原因,并采取相应的排故措施进行验证,最终排除了故障。     

某型航空发动机电子控制系统地面维护设备研究及应用

针对某型航空发动机外场保障能力匮乏、各类故障频发、关键数据信息无法获取等问题,自主研发地面维护设备,可对发动机电子控制系统中的各类数据信息进行监控、修改、存储、回放等。该系统已多次应用于外场排故、数据分析、试车验证等工作,可适应性改进后推广至相关领域。     

有翼高超声速再入飞行器气动设计难点问题

有翼高超声速再入飞行器是近年来的研究热点,气动设计是飞行器设计的关键。为了更清楚地认识有翼高超声速再入飞行器气动设计的难点问题,对有翼高超声速再入飞行器的发展、优势及总体任务剖面进行了介绍,从5个方面详细介绍了该类飞行器气动设计的难点问题,包括多约束复杂面对称气动布局设计、高温真实气体效应对气动特性影响、天地差异与天地换算方法、反作用控制系统(RCS)喷流干扰对气动特性的影响以及气动数据不确定度等,简要阐明了这些难点问题对总体设计的重要性以及初步的解决思路,为有翼高超声速再入飞行器气动设计提供了一些参考。     

Simulation and Analysis of Crashworthiness of Fuel Tank for Helicopters

Crashworthiness requirement of fuel tanks is one of the important requirements in helicopter designs. The relations among the protection frame, textile layer and rubber layer of the fuel tank are introduced. Two appropriate FE models are established, one is for an uncovered helicopter fuel tank without protection frame, and the other is for fuel tank with protection frame. The dynamic responses of the two types of fuel tanks impinging on the ground with velocities of 17.3 m/s are numerically simulated for the purpose of analyzing energy-absorbing capabilities of the textile layer and protection frame. The feasibility of the current crashworthiness design of the fuel tank is examined though comparing the dynamic response behaviors of the two fuel tanks.     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

突破技术趋同，波音再现竞争优势

 波音公司面临着来自空客公司的巨大挑战,企业战略性创新才是公司成功的关键。为此波音公司的全部战略性研究集中在扩大产品的差异性上,体现在3个方面：电子化（e-Enabled）运营环境、整体复合材料机身部件的制造技术和支持波音787客机的全球协同环境（GCE）。     

临近空间飞行器测控与信息传输系统频段选择

 临近空间飞行器是高性能信息化武器平台,测控（TT&;C）与信息传输系统是其信息保障的核心,而选择合理、可行的频段是展开系统设计的前提和基础。频段选择影响到整个技术方案的制定,是一个需综合考虑、影响深远并具有战略意义的关键问题,从国际电联（ITU）国际标准、高速数传、接收信噪比（SNR）、“三抗”、超视距中继、黑障、雨衰以及设备研制成熟度8个方面全面、细致论证了近空间平台测控系统的频段选择问题,最终得出在视距链路中以Ka频段为宜,在超视距链路中以Ku/Ka双频段为宜的结论。     

基于弯曲激波压缩系统的高超声速进气道反设计研究进展

总结了近十年来弯曲激波压缩研究的主要成果。提出了弯曲激波压缩系统的新概念,即利用特殊设计的楔形弯曲压缩面或空间弯曲压缩面,产生一系列与前缘弱激波相互交汇或叠加的压缩波系,从而使前缘激波弯曲,形成特殊的弯曲激波,它与波后的等熵压缩波来共同完成对气流的压缩。在此基础上,实现了由给定出口气动参数的超声速内流道反设计,实现了由给定压缩面压力分布和给定压缩面马赫数分布要求的型面反设计,实现了由给定激波波面的压缩型面反设计。研究证明,弯曲压缩面-弯曲激波压缩系统具有良好的综合气动性能,为高性能高超声速进气系统的气动设计提供了一种全新的设计方法。     

Experimental Study on Effects of Fuel Injection on Scramjet Combustor Performance

In order to investigate the effects of fuel injection distribution on the scramjet combustor performance, there are conducted three sets of test on a hydrocarbon fueled direct-connect scramjet test facility. The results of Test A, whose fuel injection is carried out with injectors located on the top-wall and the bottom-wall, show that the fuel injection with an appropriate close-front and centralized distribution would be of much help to optimize combustor performances. The results of Test B, whose fuel injection is performed at the optimal injection locations found in Test A, with a given equivalence ratio and different injection proportions for each injector, show that this injection mode is of little benefit to improve combustor performances. The results of Test C with a circumferential fuel injection distribution displaies the possibility of ameliorating combustor performance. By analyzing the effects of injection location parameters on combustor performances on the base of the data of Test C, it is clear that the injector location has strong coupled influences on combus- tor performances. In addition, an inner-force synthesis specific impulse is used to reduce the errors caused by the disturbance of fuel supply and working state of air heater while assessing combustor performances.     

(高)超声速流动试验技术及研究进展

近年来,与高速飞行器相关的(高)超声速流动受到了极大的关注。这类流动所具有的非定常性、强梯度和可压缩性对试验方法和风洞设计技术提出了挑战。超声速纳米示踪平面激光散射(NPLS)技术是由作者所在团队研发的非接触光学测试技术。它能够以较高的空间分辨率来揭示超声速三维流场的一个瞬态剖面的时间解析的流动结构。介绍了NPLS技术以及基于NPLS开发的密度场测量、雷诺应力测量和气动光学波前测量等方法,并回顾了这些技术在超声速边界层、超声速混合层、超声速压缩拐角、激波/边界层相互作用和光学头罩绕流等流动中的应用,清晰地再现了边界层、混合层、激波等典型流场结构及其时空演化特性。另外,为了模拟和研究高空大气条件下边界层自然转捩和超声速混合层的转捩特性,介绍了高超声速静风洞、超-超混合层风洞的设计技术以及层流化喷管的设计方法。     

Research on Auto-detection for Remainder Particles of Aerospace Relay Based on Wavelet Analysis

Aerospace relay is one kind of electronic components which is used widely in national defense system and aerospace system. The existence of remainder particles induces the reliability declining, which has become a severe problem in the development of aerospace relay. Traditional particle impact noise detection (PIND) method for remainder detection is ineffective for small particles, due to its low precision and involvement of subjective factors. An auto-detection method for PIND output signals is proposed in this paper, which is based on direct wavelet de-noising (DWD), cross-correlation analysis (CCA) and homo-filtering (HF), the method enhances the affectiv-ity of PIND test about the small particles. In the end, some practical PIND output signals are analysed, and the validity of this new method is proved.