基于B.M.E.P的活塞发动机涨圈磨合分析简

本文简要介绍了航空活塞发动机渗氮汽缸的特点,分析了汽缸磨合时在B.M.E.P作用下汽缸壁和涨圈的工作状况,并根据二者的工况特点阐明了发动机的磨合机理及影响磨合的其它因素,最后提出相应建议.     

加压煤气用活塞式压缩机的调试及常遇故障处理

总结了升压煤气用加压机的调试过程及调试中常遇到的故障处理,为调试同类设备提供了借鉴经验。     

A self- similar solution of a shock propagation in a mixture of a non-ideal gas and small solid particles

Similarity solutions are obtained for unsteady, one-dimensional self-similar flow behind a strong shock wave, driven by a moving piston, in a dusty gas. The dusty gas is assumed to consist of a mixture of small solid particles and a non-ideal gas, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-condition is maintained and variable energy input is continuously supplied by the piston. Solutions are obtained under both the isothermal and adiabatic conditions of the flow-field. The spherical case is worked out in detail to investigate to what extent the flow-field behind the shock is influenced by the non-idealness of the gas in the mixture as well as by the mass concentration of the solid particles, by the ratio of density of the solid particles to the initial density of the mixture and by the energy input due to moving piston. A comparison is also made between isothermal and adiabatic cases.     

梯形活塞环梯形面角度计算机自动测量装置

:梯形活塞环梯形面角度计算机自动测量装置电气部分由位移传感器部分、模数转换部分、电气传动部分、486PC机及打印机组成 ,装置对梯形活塞环梯形面角度自动进行两坐标测量 ,并对测得值进行数字滤波处理 ,然后根据测得的横、径向位移求出正切值并进行反正切函数计算 ,求出梯形面角度值 ,并可根据要求打印出文件报告及梯形面曲线。文章对装置设计进行了详细说明并附有系统结构图和程序框图     

往复式压缩机中活塞杆与活塞连接处结构分析

本文通过实际案例,说明活塞杆与活塞的连接处由于预紧力过大,会导致活塞杆与活塞连接的部分提前发生疲劳失效,针对该情况,本文提供了三种活塞杆与活塞连接的结构形式,并说明其安装方法。     

Improvement of chemical kinetic data at high temperatures by piston actuated shock tube,excimer laser photolysis,and atomic resonance absorption spectrometry

Qualitative improvement of chemical kinetic data at high temperatures has been achieved, to a great extent, by use of a combination of the piston actuated shock tube, the excimer laser photolysis, and the atomic resonance absorption spectrometry. Some of the important studies on elementary reactions performed recently in the University of Tokyo are demonstrated.This article was processed using Springer-Verlag T_EX Shock Waves macro package 1.0 and the AMS fonts, developed by the American Mathematical Society.     

Three-dimensional Rayleigh–Bénard instability in a supercritical fluidInstabilité tridimensionnelle de Rayleigh–Bénard dans un fluide supercritique

This paper describes the unsteady convective flow of a supercritical fluid in the Rayleigh–Bénard configuration. Two-dimensional earlier studies reported fast temperature equilibrium due to the piston effect and the development of a convective instability when the local Rayleigh number exceeds a critical value. In the present work, a high order 3D finite volume method has been developed and optimized, and to our knowledge, we show for the first time a three-dimensional convective instability in a supercritical fluid. Inspecting the time-evolution of temperature field patterns, we exhibit corner effects and a three-dimensional behavior of the flow. To cite this article: G. Accary et al., C. R. Mecanique 332 (2004).     

活塞式压缩机的管道振动原因及防振措施

对活塞式压缩机管道振动,不仅会使松散的连接管和阀门,配件,也可能使管道疲劳损伤和裂纹,会引起介质大量的泄漏出来,进而会引发爆炸或者是燃烧。活塞式压缩机振动保护是一个非常非常重要的课题。在本文中,活塞压缩机管道振动及防振措施进行了分析,并提出了防振措施。     

大功率柴油机的连杆设计

介绍了大功率柴油机连杆设计的方法和原则。通过对连杆静力和动力的综合分析，解释了连杆设计中的关键问题，为大功率柴油机的连杆设计提供了一种实用的设计方法。     

热障涂层活塞热应力高阶控制体有限元法研究

为研究热障涂层（thermal barrier coating, TBC）活塞热应力问题,本文发展了一种针对复合材料热力问题的三维高阶控制体有限元法(CV-FEM). 我们基于10点高阶四面体单元,对控制方程数值离散过程做了详细推导; 利用交错网格技术,将待解变量及材料物性参数分别存储在单元节点以及单元中心; 采用高阶CV-FEM对圆环热应力问题进行了数值验证,计算结果与ANSYS吻合良好; 数值模拟了层和型及功能梯度型（functional graded material, FGM）活塞热应力问题. 结果表明：活塞的最大温度位于燃烧室与活塞顶面的交界区域;最大应力位于粘结层附近,改变层和型TBC活塞材料组分、材料分布或改变FGM TBC活塞的材料梯度系数,均不能有效降低最大应力幅值;通过在粘结层内引入材料属性由金属基体材料到粘结剂材料过渡的FGM,可以有效降低层合型及功能型TBC活塞涂层内应力幅值,使应力幅值下降20%～30%,改善了应力集中问题.