液压性能综合实验模拟系统的开发

Automation Studio是一种有效的液压系统仿真工具。在对QCS003试验台的系统与工作原理分析的基础上,在Automation Studio平台上开发了液压性能综合实验模拟系统,利用该系统可以在计算机上完成实验项目。     

WANDFULH液压比例阀在多功能液压试验台设计中的应用

比较详细的介绍了世界著名的液压元件公司—WANDFULH（瑞士）的液压比例阀在流量和压力控制方面的几种不同应用,并介绍了相应的Amplifier／oontmller card sd1伺服放大控制板的电路连接和软件应用,以及液压实验台的参数、功能要求和调试过程。     

低温液体推进剂充填管路的数值模拟

研究了低温液体推进剂供应管路预冷充填过程的计算方法, 利用一维均相平衡态流体动力学模型和涵盖预冷过程中主要传热工况的传热模型, 考虑了低温液体推进剂的可压缩性, 用有限容积法求解管流方程, 用有限差分法求解管壁内的一维非稳态导热方程.计算了某型低温液体推进剂火箭发动机实验台系统供应管路的预冷充填过程, 分析比较了仿真与实验的结果, 为发动机和实验台系统的改进及新系统的设计提供了依据, 仿真结果及分析结论已应用于现有发动机实验台系统的改造和长距离液氢输送管道的设计中.      

2500吨双螺杆液压螺旋压力机

山东省胶县锻压机械厂与济南铸锻机械研究所共同设计研制成功了我国第一台JA58—2500型2500吨双螺杆液压螺旋压力机。该机采用双螺杆推缸式结构,由主机、液压、电器三部分组成。主机包括机身、传动、滑块、上顶料和下顶料。机身由横梁、左立柱、右立柱、底座组成框架结构,用螺栓、销钉及圆锥销连接。铜螺母固定在滑块内,而滑块置于机身框架中央,可做上下往复运动。主螺杆左右各一根,其螺纹旋向相反,它们将机身、滑块连成一体,只作旋转运动。主螺杆的上方装有齿轮,一方面储蓄能量,另一方面     

滚子叶片液压马达研制成功

遵照毛主席关于“独立自主、自力更生”的方针,北京航空学院根据国外资料照片进行了YM-28滚子叶片液压马达的设计,并由我厂试制成功。一、滚子叶片液压马达简介滚子叶片液压马达是五十年代出现的一种新型结构的液压马达。它与活塞式、柱塞式液压马达截然不同,结构较为简单,各方面性能都较优越但零件精度、光洁度要求很高。到了六十年代,这种马达开始应用于电器液压伺服     

北京航空航天大学燃烧与红外研究课题组介绍

课题组 主要建有可视化贫油熄火实验台、横向射流初始雾化观测实验台、气动制冷／加热模拟实验台、微通道热沉换热性能试验台、本生灯火焰稳定实验台、双涵道波瓣混合性能实验台、雾化性能测试实验台等，主要从事与航空发动机燃烧及红外辐射有关的课题研究，探索其涉及的基础科学问题及应用技术问题。目前与美、法、英、加等国建立了可靠学术联系，在基础科学研究部分已开展广泛合作，已与国外名校联合培养博士生3名。     

△×52立铣改装三座标液压仿形铣

一三九厂和三○三研究所坚持厂、所结合和工人、干部、技术人员三结合的原则,用四个多月的时间,将一台X52型立式铣床改装为三坐标液压仿形铣床,经调试、试用,性能良好。所采用的仿形头是三○三研究所和三二七七厂共同研制的3-YZF-1型三坐标液压自动     

YC7-001型单泵液压油车制造缺陷分析与改进

就YC7-001型单泵液压油车在性能试验中暴露出来的诸多问题,通过进行分析和论证,找出了设计、制造中的主要缺陷,经过改进,取得了明显效果. YC7-001型单泵液压油车是中国一航吉林航空维修有限责任公司20世纪70年代初为翻修空军装备的某原型飞机而设计制造的.其用途是飞机在地面上模拟空中做起落架收、放等性能试验用.     

轮廓仿形误差分析

前言我们于1975年研制成功的3-YZF-Ⅰ型仿形头,与配套的液压仿形铣床组成了具有气液反馈的液压伺服系统。它由仿形铣床、油泵站、仿形头三大部分组成。经鉴定列为国家成套产品的有:XF5032型、XFY6325型、XF5050型等立铣。     

信息服务

本刊继续为读者提供代购计量检定规程规范、图书、教材等方面的服务。以下是以往我们没有刊登过的规程规范、图书目录 ,读者如有需要请与我们联系 ,我们会尽力为大家提供优质的服务。序号书　　名 定价(元 )1 JJG2 2 - 2 0 0 3内径千分尺 1 5.0 02 JJG2 4 - 2 0 0 3深度千分尺 1 4 .0 03 JJG51 - 2 0 0 3带平衡液柱活塞式压力真空计 1 5.0 04 JJG67- 2 0 0 3工作用全辐射温度计 1 6.0 05 JJG1 1 1 - 2 0 0 3玻璃体温计 1 5.0 06 JJG1 77- 2 0 0 3圆锥量规 1 5.0 07JJG2 75- 2 0 0 3多刃刀具角度规 1 2 .0 08JJG41 4 - 2 0 0 3光学…     

基于飞机油箱模型形状特征油量测量切片步长选择方法研究

 在分析飞机数字式油量测量过程中目前广泛使用的切片法油量测量原理的基础上,针对现有的定步长切片法无法得到准确、可靠的燃油质量特性数据库的缺陷,结合对飞机油箱模型形状特征的分析,提出了基于飞机油箱模型形状特征的油量测量切片步长选择方法。此方法包括切片步长整体和局部选择两个过程,整体选择以实现相邻两切片平面所夹油箱模型体积近似相等为目的来确定切片步长,以体现油箱模型截面整体变化规律;局部选择以设计切片平面与截面突变平面重合或尽可能接近的方式,突出油箱截面的局部变化特征。实验结果表明：该切片步长选择方法较定步长方法能够建立更为合理、可靠的燃油质量特性数据库,从而提高了油量测量精度。     

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.      

二维翼段颤振的μ控制

 采用超声电机作为作动器来实现含控制面的翼段颤振鲁棒抑制。针对作者设计的二维翼段颤振主动抑制系统，通过理论与实验相结合的方法，建立了考虑沉浮方向阻尼和作动器模型参数不确定性的控制系统模型，设计了μ控制器，并对控制器做了降阶处理。数值仿真和风洞试验表明，μ控制器可有效地抑制颤振的发生，将颤振临界速度提高23.4%。相对于H_∞控制器，μ控制器的控制效果和鲁棒性更好。     

Abnormal Shape Mould Winding

为解决网格化芯模的缠绕问题,本文提出了复合材料面片缠绕机理;接着详细分析了面片缠绕过程中的芯模凹曲面上纤维滑线和架空现象,应用微分几何曲面理论和空间几何理论,提出判据及其解决方案;最后,针对飞机发动机进气道的缠绕成型,编制缠绕控制程序并进行相应的实验,验证了面片缠绕方法的可行性。     

基于H∞性能指标的质量矩拦截弹鲁棒控制

 以所建立的质量矩拦截弹数学模型为基础，利用微分几何的反馈线性化理论，得到一个解耦线性系统，考虑到拦截弹的鲁棒性要求和3个滑块的协调控制问题，提出采用双回路的设计方法，内回路采用线性二次调节器（LQR），外回路采用考虑混合灵敏度问题的H_∞控制设计。仿真结果证明了该方法动态性能满足设计要求，同时对系统参数的不确定性具有较强的鲁棒性。     

航天器返回地球的气动特性综述

航天器返回地球的飞行过程中,气动特性是实现将宇宙飞行速度减到落地前速度、保证再入飞行得到有效控制以及再入防热安全可靠的关键因素。针对简单旋成体气动外形、半弹道式再入控制、烧蚀防热类返回航天器,综述了返回地球过程中变化的空气流域特性、航天器周围的气体绕流环境、空气与航天器作用产生的动力学与热效应等。系统地给出了该类航天器的再入气动特性参数与飞行性能的共性规律,包括:气动阻力与再入减速、气动升力与再入轨迹控制、配平攻角与飞行稳定性、气动加热与防热,以及再入过程中不同气动特性航天器、气象条件变化等对再入飞行性能的影响规律。为航天器开展返回飞行过程的跨流域气动性能工程研制提供设计参考。     

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.     

Effects of Mo on the Microstructure and Hydrogen Sorption Properties of Ti-Mo Getters

The effects of Mo on the microstructure evolution, porosity and hydrogen sorption properties of Ti-Mo getters are investigated in this work. The results show that the addition of Mo prolongs the densification process of Ti-Mo getters and results in a significant amount of sintered pores. With the Mo content increasing, the porosity of getters firstly increases reaching the maximum value as it at- tains about 7.5wt.%, and then drops. At the room temperature, the hydrogen sorption property of getters increases progressively with the Mo content increasing, but the tendency is not very clear before its content lies below 2.5wt.%. When the Mo content achieves about 7.5wt.%, the hydrogen sorption property proves to be the best. The discussion is made about the above mentioned phenomena inclusive of hydrogen sorption properties of getters under different activation conditions (from 500-750 ℃).     

Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.