An experimental study of the dual-loop control of electro-hydraulic load simulator （EHLS）

This paper investigates motion coupling disturbance（the so called surplus torque）in the hardware-in-the-loop（HIL）experiments.The＇＇velocity synchronization scheme＇＇was proposed by Jiao for an electro-hydraulic load simulator（EHLS）in 2004.In some situations,however,the scheme is limited in the implementation for certain reasons,as is the case when the actuator＇s valve signal is not available or it is seriously polluted by noise.To solve these problems,a＇＇dual-loop scheme＇＇is developed for EHLS.The dual-loop scheme is a combination of a torque loop and a position synchronization loop.The role of the position synchronization loop is to decouple the motion disturbance caused by the actuator system.To verify the feasibility and effectiveness of the proposed scheme,extensive simulations are performed using AMESim.Then,the performance of the developed method is validated by experiments.     

空气压缩机的经济运行及使用寿命初探

以空压机技术理论为依据，结合实践经验，分析了空压机常见故障及解决方法。阐述了延长空压机使用寿命的途径，提出了空压机处于最佳运行状态的措施。     

乘波体前体气动特性数值计算及实验验证

对机身/发动机一体化构型的乘波体的气动特性进行了数值计算和分析,采用格心格式的有限体积方法求解雷诺平均N-S方程,对一体化构型的乘波体三维粘性流场进行了数值计算,同时对同一构型的测压模型进行高超声速测压风洞实验,计算结果与实验吻合良好。结果表明：乘波体具有高升力、低阻力及大升阻比特性,飞行器前体预压缩效果明显,气动特性良好。     

弹性支承下弧齿锥齿轮齿面接触特性的理论与实验研究

航空发动机采用弹性支承后,转子弹性变形会造成主传动弧齿锥齿轮相对位置的变化,从而影响齿面接触性能。针对某型涡喷发动机转子系统,分析求解了弹性支承下齿轮安装处的变形,并将其等效地转化为齿轮副间的安装距偏差,在此基础上,完成了弧齿锥齿轮齿面接触特性分析。在转子系统模拟试验台上,对发动机主传动锥齿轮接触性能进行了实验研究。分析与实验结果同时表明支承刚度对齿面接触区和传动误差皆有很大影响。     

磷光热图测热技术研究

磷光热图测热技术基于磷光材料的温度敏感特性,是应用于风洞热环境测量的新型全场热流测量方法,近年来在欧美等国得到了高速发展。在中国航天空气动力技术研究院搭建了一套磷光热图系统,采用20°压缩拐角模型开展了重复性试验及铂薄膜电阻温度计对比和纹影验证试验。试验结果表明：热流测量特征区域结果与纹影照片符合良好;技术自身重复性误差小于5%;平板热流与理论值误差小于10%;与铂薄膜电阻温度计的对比误差小于20%,此误差主要由铂薄膜电阻温度计的测量散布度引起。该技术通过单次试验获得模型全场热环境数据,且能够捕获热流峰值区域,是一种全面高效的热环境测量手段。     

Experimental study of hydrogen-rich/oxygen-rich gas-gas injectors

Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injector, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor＇s wall temperatures were obtained for different design parameters through the experiments. It can be con- cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.     

大后掠翼大迎角定常与非定常俯仰气动特性及其控制

 对装有“前端襟翼”和“前缘襟翼”的74°后掠三角翼, 在迎角0°～ 90°范围的定常和非定常 (俯仰振动, f = 0. 4, 0. 8, 1. 2Hz) 的空气动力特性以及襟翼的控制作用作了实验研究。定常流的实 验结果与解N 2S 方程的计算结果作了比较。非定常俯仰振动使气动特性的变化出现迟滞现象, 但 仍能保持襟翼对定常流控制所具有的优越性。不装襟翼的三角翼的部分校测结果与文献中相应数 据一致, 表明实验结果可信。     

翼型低速动态测压实验的初步分析

简述了翼型低速动态实验研究的测试设备和实验方法，给出了ＮＡＣＡ００１２翼型动态测压的实验结果，初步分析了影响翼型动态气动特性的因素。将所得实验结果与国外实验结果及理论计算结果进行了对比与分析，实验结果与资料值有较好的一致性。     

非平衡电弧加热射流光谱学诊断方法：第一部分 氩射流

从一般意义上给出了非平衡电弧加热射流光谱学诊断方法和结果。表明非平衡亚声速电弧加热射流中心是ＬＴＥ的，沿径向形成一非平衡囊兜，囊兜的最深位置约在１／２射流半径处。