航空发动机积炭清洗剂初探

本文简介了积炭的形成过程及其危害，国内外现有去炭工艺水平，重点分析了有机积炭清洗剂各成份的作用和影响，确定了工艺配方，并对其性能和使用情况作了测试。     

Laser beam weld-metal microstructure in a yttrium modified directionally solidified Ni3Al-base alloy

The microstructure of laser beam weld-metal of an yttrium doped directionally solidified alloy IC 6A, with chemical composition Ni–16Al–8.5Mo–0.12B–0.05C–0.03Y (at.%) was studied. The dendritic microsegregation observed within the fusion zone indicated that dendrite cores were slightly depleted in molybdenum and aluminum and the interdendritic regions were also considerably enriched in yttrium. Severe cracking in the weld-metal was observed and was found to be closely associated with interdendritic eutectic-type microconstituents identified as consisting of γ, γ′ and Ni–Mo phases. An yttrium-rich phase (Ni₃Y) was observed in some interdendritic regions containing the eutectic γ, γ′ and Ni–Mo products. Their formation was discussed in relation to plausible microsegregation induced alteration of primary solidification path during cooling from welding temperatures.     

基于遗传算法的发动机需求量组合预测方法

阐述了基于改进遗传算法组合预测的原理，给出了此类组合预测的建模方法及有效性评价指标。在军用航空发动机采购需求量的预测中，运用计算机仿真的方法对比了多种预测方法，验证了组合预测法的有效性和准确性。     

某发动机Ⅱ级涡轮叶片排气边裂纹分析

对WP13F发动机Ⅱ级涡轮叶片排气边裂纹、断裂进行了汇总分析。该叶片裂纹、断裂都属于以低周疲劳为主的高、低周复合疲劳失效模式；在疲劳起始区均存在一个黑色粗糙区(月牙形多晶区)；断口上存在的大量粗大初生碳化物降低了材料的断裂韧性，加速了疲劳裂纹的扩展。     

某发动机一级涡轮叶片断裂分析

以某发动机涡轮一级事故叶片为研究对象,对断裂叶片进行了宏、微观形貌观察,硬度测试以及断口成分检查,分析了叶片裂纹的产生与发展过程,探讨了叶片断裂失效的原因。结果表明,叶片断裂模式为机械疲劳断裂。提出了预防措施。     

航空发动机液压负载系统设计及应用

为了提取某型航空发动机带动液压泵的机械功率,通过分析航空发动机液压负载系统现状,结合被试对象和试飞平台设计研制了某型航空发动机液压负载系统,详细阐述了该系统的工作原理,并进行了换热计算、管路压力损失计算、集成安装设计等。经地面调试和飞行试验验证,结果表明:系统集成度高、换热效果好、维护性好,能够满足该型航空发动机液压泵机械功率的提取要求。     

一种航空发动机SVM模型辨识方法与仿真

航空发动机是一个十分复杂的气动热力过程系统,具有很强的非线性,为了对航空发动机进行有效的控制及故障诊断,研究其工作特性,必须建立其数学模型。依据某型航空发动机试验数据,采用基于将试验数据代入对象方程的算法进行系统辨识,建立了该型发动机某一稳态点的状态变量数学模型(State Variable Model)。验模表明,所建模型精度较高,鲁棒性好,能够实时准确反映发动机性能,满足后续控制系统的研究和设计。     

故障检测滤波器的鲁棒性设计

该文设计了全维非线性未知输入观测器，实现检测滤波器对于被控对象模型误差和系统不确定性因素的干扰解耦。某型航空发动机控制系统传感器和执行机构的故障检测仿真实验表明，具有干扰解耦的故障检测滤波器可以准确地对传感器和执行机构的故障进行检测和隔离，提高了检测滤波器对于故障检测的鲁棒性。     

Effect of alloying elements on the behaviour of TiAl-based alloys

TiAl-based alloys containing Nb, Mo and Cr have been produced by induction melting both under an Ar atmosphere and in vacuum. Fracture toughness and isothermal oxidation tests at 900 °C have been performed on a number of alloys in order to evaluate the effect of alloying elements on both fracture toughness and hot corrosion. The results highlighted that there is an alloy composition range that could allow to obtain a good compromise between high temperature oxidation resistance and fracture toughness. In fact only for a selected Al/Ti ratio and a limited content of alloying elements it is possible to attain the alloy microstructural control and, for Mo free alloys, good protectiveness against oxidation.     

某型航空发动机常见振动故障分析

针对某型发动机结构特点以及装配过程中与振动相关的要素,分析该型发动机生产过程中常见振动故障情况,包括转子不平衡、转子不平衡与转静件碰摩并发故障、转子不对中、高低压涡轮转/静件碰摩以及设备原因,总结了该型发动机常见振动故障诊断及排除方法.