航空发动机转子泵阻力矩特性计算方法

在航空发动机研制过程中,需要确定起动过程中的附件机匣传动附件的阻力矩与转速的关系,以便利总体起动方案设计。研究了航空发动机中常用的转子泵起动过程阻力矩计算方法,给出了1种阻力矩特性计算方法,并计算了某型航空发动机转子滑油泵组起动过程的阻力矩。     

伺服机构恒压变量泵压力脉动分析

对某运载火箭整箭测试中一级伺服机构出现压力脉动的原因进行了分析。根据伺服机构变量泵原理,认为引起压力脉动的主要因素是变量泵调节机构。建立了变量泵的仿真模型,讨论了变量调节机构灵敏度和管路结构等其他因素对变量柱塞泵输出压力脉动的影响,以及压力脉动对控制元件和执行元件的影响。结果表明:变量泵的低频小幅值压力脉动对整个伺服系统的控制元件和执行元件均无影响。伺服机构能正常稳定地工作,保证运载火箭的飞行可靠性。     

集成式电动燃油泵控制规律研究

为实现对电动燃油泵供油量的有效控制,首先在分析处理实验数据的基础上研究了电动燃油泵的供油特性,并利用AMESim仿真软件建立了集成式电动燃油泵数学模型。以此为基础构建了燃油泵PID控制系统,仿真中用经验试凑的参数整定方法给出了最优的控制参数,达到了预期的控制效果。为控制系统的调试试验提供了理论依据。     

Fault diagnosis of an intelligent hydraulic pump based on a nonlinear unknown input observer

Hydraulic piston pumps are commonly used in aircraft. In order to improve the viability of aircraft and energy efficiency, intelligent variable pressure pump systems have been used in aircraft hydraulic systems more and more widely. Efficient fault diagnosis plays an important role in improving the reliability and performance of hydraulic systems. In this paper, a fault diagnosis method of an intelligent hydraulic pump system (IHPS) based on a nonlinear unknown input observer (NUIO) is proposed. Different from factors of a full-order Luenberger-type unknown input observer, nonlinear factors of the IHPS are considered in the NUIO. Firstly, a new type of intelligent pump is presented, the mathematical model of which is established to describe the IHPS. Taking into account the real-time requirements of the IHPS and the special structure of the pump, the mechanism of the intelligent pump and failure modes are analyzed and two typical failure modes are obtained. Furthermore, a NUIO of the IHPS is performed based on the output pressure and swashplate angle signals. With the residual error signals produced by the NUIO, online intelligent pump failure occurring in real-time can be detected. Lastly, through analysis and simulation, it is confirmed that this diagnostic method could accurately diagnose and isolate those typical failure modes of the nonlinear IHPS. The method proposed in this paper is of great significance in improving the reliability of the IHPS.     

液环泵叶轮叶片轴向叶顶间隙微射流流动机理及性能分析

液环泵的轴向间隙泄漏流对其水力性能有重要的影响,为了抑制其叶片轴向叶顶间隙泄漏流动,提升水力性能,以2BEA-203型液环泵为研究对象,在叶片轴端间隙引入微射流,采用数值模拟方法对比分析微射流对间隙泄漏流场及液环泵性能的影响机理。分析结果表明:轴向间隙射流能够有效地抑制间隙泄漏,液环泵的效率及真空度均在一定范围内提升。叶片轴向间隙内射流孔出口处会形成一相对高压区,微射流排挤占用一部分间隙的流道,部分射流与压力面泄漏流相互作用形成间隙涡,阻滞泄漏流动,使得叶片间隙泄漏流强度降低,叶片背面后方的泄漏涡前移。液环泵叶轮轴向间隙泄漏流存在复杂的时空分布特征,湍动能分布由吸气区沿叶旋方向逐渐增强,受微射流抑制作用,射流型叶轮间隙吸力面侧的湍动能强度要明显弱于原型叶轮间隙;泄漏流强度沿弦线方向逐渐减弱,微射流的部分流体沿弦线方向流入叶片轴向间隙,排挤占用下游间隙的流道,提升了叶顶间隙的密封性能。      

Influence of shock attenuation on tailored operation in free piston shock tunnels

The free piston shock tunnel is a type of shock tunnel with high performance. For this type of tunnel, the influence mechanism of shock wave attenuation on tailored operation is explored by numerical simulation and theoretical analysis. By introducing the normalized velocity, the simple constraint equation for shock wave under the tailored operation is deduced. Moreover, the real gas effect is also taken into account in this equation. Based on the equation, the tailored operation of shock tunnels can be predicted with very few calculations. The present study shows that the change rate of the thermodynamic state of the gas behind the shock wave is inconsistent with the attenuation rate of the shock wave, which is the fundamental reason why the wind tunnel achieves tailored operation at a lower Mach number of shock waves. This lower Mach number of shock waves differs from the corresponding ideal value by a factor, which is about the square root of shock attenuation rate.     

航空发动机滑油泵高空性分析

从流体力学角度,对滑油泵的高空性进行了系统的理论分析:阐述了其产生原理,推导了各种影响因素之间的关系式,得出了如下结论:泵前总阻力系数、滑油密度、油泵设计流量越小,入口管径越大,越有利于保持泵的高空性;而对于转子泵,内齿轮1齿扫过的面积越小,内齿轮齿数越少,内齿轮转速越低,转子宽度越小,越有利于保持高空性;对于齿轮泵,模数和齿数越少,转速越低,转子宽度越小,越有利于保持高空性。反之,则不能保持高空性。     

一种新运行方式脉冲燃烧风洞研制及初步应用

介绍了一座喷管口径为600mm、利用氢与富氧空气混合燃烧产生高焓试验气流的脉冲风洞.风洞首次采用了活塞挤压为加热器供应燃料和路德维希管供应富氧空气的工作方式,实现了风洞试验过程中需多少燃料就供多少燃料,消除了采用路德维希管供燃料存在的弊端.自主研制的大通径快速阀取代了膜片,提高了设备运行效率.风洞在吸气式高超声速技术研究中得到了成功应用.     

燃油柱塞泵配流机构泄漏模型

泄漏量是微缝隙密封的重要性能参数之一.燃油柱塞泵运行时配流机构密封面为楔形而非完全平行,为准确计算泄漏量继而分析燃油泵的容积效率,获得合适的密封缝隙高度,提出一种楔形密封缝隙的泄漏模型,推导了基于平行与楔形密封面间隙流动的配流机构泄漏量公式.该模型考虑了定密封件的结构尺寸和动密封件倾侧角的影响.仿真结果表明,膜厚对配流机构泄漏流量的影响较大,楔形与平行密封泄漏量随膜厚增加差异增大,供油压力高时尤为明显.     

某型直升机离心式燃油增压泵增压值设计

为研制满足某型直升机供油系统使用包线的离心式燃油增压泵,在Matlab/Simulink仿真平台上创建了供油系统仿真模型,并对该供油系统进行了仿真分析,给出了离心泵的增压值指标.进行了供油系统地面模拟试验,并与仿真计算进行了对比,结果表明:与发动机的断油试验相比,仿真计算的相对误差为2.8％;与发动机正常供油试验结果相...