某型航空发动机高温总压探针基础激励疲劳寿命研究

被试航空发动机内涵高温区测试探针的可靠性直接关系发动机试飞试验安全,对其进行疲劳寿命进行预估十分必要。根据Steinberg提出的基于高斯分布和Miner法则的三区间法,结合某型发动机低压涡轮导向叶片截面的总压探针试验时工作环境,推导出发动机基础激励下该总压探针疲劳寿命模型;通过对总压探针所安装的发动机大量试飞试验数据统计分析,得到该总压探针的实际工作温度环境,并进行温度区间划分,计算各区间时间占比、平均频率等;最后通过Ansys软件计算该总压探针在划分的各温度区间下的最大等效应力,代入疲劳寿命模型得出该总压探针的疲劳寿命,从而为被试发动机试飞试验的安全可靠性提供参考。     

某型航空发动机高温测头应力研究

对被试航空发动机内涵涡轮处测头进行应力分析是测头强度计算及寿命准确预测的关键。针对某型航空发动机涡轮前的高温压力测头,分析了其工作时受到的载荷情况,通过试验数据及基于有限元软件进行分析计算,得出了该高温测头工作时受到基础载荷、气动载荷和热载荷作用下的合应力及各载荷对合应力的贡献,分析计算表明,热载荷是高温测头工作时应力的主要贡献者,计算结果为该高温测头设计和加工提供依据,保证了试飞试验安全。     

矿井轴流通风机轮毂的强度校核与模态分析

在完成矿井轴流通风机整机设计的过程中,针对风机主要受力部件轮毂进行了强度校核计算,并采用有限元分析方法对轮毂进行了模态分析,得出轮毂的关键固有频率和振型,为机械产品的动态设计提供依据.通过理论计算与有限元仿真方法有机结合,提高了设计的可靠性.     

高压航空燃油齿轮泵的齿轮强度校核及应力仿真分析

以某型外啮合高压航空燃油齿轮泵为研究对象,推导齿轮理论强度校核计算公式及校核流程,对其齿轮进行强度校核;通过计算机CAD技术建立齿轮泵三维模型,基于ANSYS进行齿轮的动态啮合过程、静态接触应力、静态弯曲应力仿真;将3种仿真结果与理论校核结果进行对比,表明该仿真技术能够有效实现该型泵的应力仿真分析.应力分布结果表明:齿...     

某微型航空发动机涡轮强度的计算分析

本文运用有限元方法研究某微型航空发动机涡轮强度,借助ANSYS软件对涡轮进行分析,确定涡轮在工作转速下应力分布与变形,并考虑温度应力及材料非线性的影响,提出在耦合情况下涡轮的应力分布和变形,最后改变结构讨论涡轮的应力变化,为结构设计和改造提供理论依据。     

发动机前罩壳结构设计及校核

以某发动机的前罩壳、机油泵一体化结构为例,介绍了发动机前罩壳的结构设计方法及CAE分析校核。     

基于ANSYS的某航空活塞发动机凸轮轴模态分析

选取某水平对置四缸航空活塞发动机的凸轮轴为分析对象,在介绍模态分析基本理论的基础上,采用ANSYS Workbe nch软件平台对凸轮轴进行三维实体建模和有限元分析,选取Block Lanczos法计算了该凸轮轴前10阶固有频率和振型,对计算结果进行分析发现了该凸轮轴固有模态的规律。为该凸轮轴的后续结构分析和排除故障提供依据的同时,也为其他多汽缸活塞发动机凸轮轴的固有模态分析提供了便于工程应用的方法。     

航空机轮轴承载荷分析及强度校核

通过对航空机轮圆锥滚子轴承的受力分析,建立机轮轴承的强度校核方法,以作为机轮轴承的选型及设计依据。     

某型地铁车辆转向架构架强度及模态分析

通过CATIA软件建立某型地铁车辆转向架构架的三维实体模型,采用HyperWorks建立了该型地铁转向架构架结构强度分析的有限元模型,参照铁路相关标准,计算得到其强度分析应力结果,验证了该构架结构设计的合理性。通过模态分析,获得该构架的各阶模态频率及模态振型,为构架的动态特性设计提供参考。     

Fast-response total pressure probe for turbomachinery application

To evaluate the accurate performance and characteristics of turbomachinery, it is important to measure the unsteady flow phenomena downstream of the rotating blades. This paper presents the development of a fast-response total pressure probe for the measurement of the total pressure field at the exit of blades. The result of measurement in a one-stage axial turbine is also presented. The fast-response total pressure probe is fabricated by installing a fast-response pressure sensor in the cylindrical head of the probe. In terms of simplicity of the measurement system and data reduction method, this method is more competitive over established methods that use more than four sensors. The probe is applied to the one-stage axial turbine in order to measure the instantaneous total pressure downstream of rotor blades. The measured instantaneous signal is decomposed to obtain the blade-to-blade pressure distribution. The pressure distribution due to blade passing is clearly captured. Due to the loss generation in the casing region, the total pressure and its amplitude of fluctuation by the blade passing are lower in the shroud and hub region than in mid-span. The total pressure distribution at the exit of the rotor blade is found to be slightly different from blade to blade due to the geometric difference and the different relative positions of the rotor blades and stator vanes. The developed probe successfully measures the accurate total pressure distribution at the rotor exit, and allows the evaluation of the loss distribution and the accurate performance of turbomachinery.     

柴油机活塞设计分析及强度校核研究

伴随着现代柴油机的高强化发展需求,提高最大爆发压力是强化柴油机的一种措施。随着柴油机的最大爆发压力越来越大,结构要求越紧凑,作为柴油机重要零部件的活塞从结构设计和材料上都有新的发展。本文对4L132柴油机的活塞从材料、头部、销部、裙部分别进行设计,并对该活塞强度计算验证,从而为强化柴油机活塞部分提供相关理论依据。     

止回阀水力特性分析及水击计算

介绍了止回阀水击压力计算的2种方法——特征线法和特性曲线法，前者严密准确，计算较复杂，需借助计算机求解；后者为一种近似计算法，简单方便，易于工程人员掌握和使用。     

Numerical modeling of an aspirated total temperature probe

Computations using a model of an aspirated total temperature probe are compared with some classical experimental data from NACA Lewis Laboratory and with a numerical solution using CFD ACE+. Convection and radiation to and from the probe surfaces, radiation from the hot gas surrounding the probe, and conduction in the probe materials are computed by the model. The model consistently predicted the recovery temperature to within about 5 degrees R (3 K) for a temperature range of 1500 to 2500 R (833 to 1389 K).     

Atom probe tomography of reactor pressure vessel steels: an analysis of data integrity

In this work, the importance of optimising experimental conditions for the analysis of reactor pressure vessel (RPV) steels using atom probe tomography is explored. The quality of the resultant atom probe data is assessed in terms of detection efficiency, noise levels and mass resolution. It is demonstrated that artefacts can exist even when experimental conditions have been optimised. In particular, it is shown that surface diffusion of some minority species, including P and Si, to major poles prior to field evaporation can be an issue. The effects were most noticeable during laser pulsing.The impact of surface migration on the characterisation of dislocations and grain boundaries is assessed. The importance of selecting appropriate regions of the reconstructed data for subsequent re-analysis is emphasised.     

"太空船"游艺机回转臂的强度校核计算分析

游乐设施设计文件必须经核准的技术机构进行鉴定,执行设计审查程序,就太空船游艺机回转臂的强度校核计算分析,阐述了塑性材料一般应采用的计算方法和原则.     

Modal characteristics and fatigue strength of compressor blades

High-cycle fatigue (HCF) has been identified as one of the primary causes of gas turbine engine failure. The modal characteristics and endurance strength of a 5 MW gas turbine engine blade developed by Doosan Heavy Industries & Construction Co., Ltd. in HCF fracture were verified through analysis and tests to determine the reliability of the compressor blade. A compressor blade design procedure that considers HCF life was performed in the following order: airfoil and blade profile design, modal analysis, stress distribution test, stress endurance limit test, and fatigue life verification. This study analyzed the Campbell diagram and estimated resonance risk on the basis of the natural frequency analysis and modal test of the compressor blade to guarantee safe and operational reliability. In addition, the maximum stress point of the compressor blade was determined through stress distribution analysis and test. The bonding point of the strain gage was determined by using fatigue test. Stress endurance limit test was performed based on the results of these tests. This research compared and verified the modal characteristics and endurance strengths of the compressor blades to prevent HCF fracture, which is among the major causes of gas turbine engine damage. A fatigue life design procedure of compressor blades was established. The 5 MW class gas turbine compressor blade is well designed in terms of resonance stability and fatigue endurance limit.     

某城镇客车车身骨架模态分析与结构优化

自由模态分析法是获取客车车身骨架结构模态参数重要途径之一,模态参数反映了车身结构固有振动特性,与客车整体结构的使用寿命、乘坐安全性与舒适性等密切相关。在LMS Virtual.Lab中进行该城镇客车车身骨架结构的模态分析,通过约束骨架地板四周,对模态结果进行分析,在低频范围下,工程实际最为关心的三阶中,骨架顶部一阶垂弯变形量较大,达到了9.5 mm。通过对顶部进行结构优化,在骨架顶部应变较集中处增加加强筋与加强块板,对顶部改进后再次进行模态分析,一阶垂弯降低为4.76 mm,验证了该修改方案能够有效改善车身骨架振动特性这一优化目标。     

高压电站止回阀的设计选用与理论分析

简单列举了电站用止回阀的种类,重点介绍了两种高压止回阀结构形式,详细分析了截断类阀门和止回类阀门关闭时产生水击的过程和区别,指出了水击对阀门选择的影响,对两种止回阀关闭时产生的冲击进行了定性对比分析,给出了高压电站止回阀选用注意事项。