Research on influence of typical microstructure characteristics of Ni base single crystal on creep rupture and deformation analysis of turbo blade

Considering the influence of typical microstructure characteristics on creep performance,a series of UM-F single crystal alloys which had similar element components but different microstructures were used to analyze the relationship between creep life and microstructure characteristics of Ni base single crystal.Three main factors were proposed:misfit,volume fraction of precipitate and maximum matrix channel width.The Microstate parameter Ymicro was established to estimate the deformation state of the materials.The linear relationship between the initial value of microstate parameter Y0 and creep life under a certain temperature/load was affirmed.By analyzing the high temperature region of turbo blade using the material parameters of DD 3,the creep deformation and the life prediction of the critical points of blade were obtained and the result closed to the test.     

基于XTCE标准的遥测数据处理软件架构研究

XTCE(基于可扩展标记语言的遥测遥控信息交换)数据规范是CCSDS(空间数据系统咨询委员会)发布的空间任务遥测遥控信息描述模型和数据交换格式,旨在为遥测遥控信息定义提供一种标准方式,进而减少遥测数据处理软件支持异构任务的工作量,减少开发成本,缩短开发周期,降低开发风险.本文首先介绍XTCE的整体框架,重点介绍了XTC...     

第三流体循环发动机性能分析

为了提高发动机循环性能,以某发动机设计参数为基础,以R22、乙烷及乙醇3种介质为对象,进行了第三流体循环发动机性能分析。在性能分析过程中,耦合了系统参数平衡计算与身部传热流阻仿真计算结果,力求使分析结果更接近实际情况。分析结果表明,第三流体循环与传统方式相比,可以提供更高的燃烧室压力,其中采用乙烷为循环介质的第三流体循环发动机性能最高。     

快速原型开发方法在数据库应用系统设计和实现中的应用

主要介绍了快速原型开发方法在数据库应用系统设计和实现中的应用,并重点阐述了快速原型开发方法的思想和开发过程.     

线性规划的非可行的内点算法

首先简要介绍非可行的内点算法,然后提出一种新的中心路径的取法,并由此给出一个对Kojima-Megiddo-Mizuno算法的改进的方法,这一新的算法是具有O(n2L)次收敛性的算法,并对这一算法的收敛性加以证明,这一新的算法与其它算法最明显的差异是不必假设LP解的存在性,就可以证明原始—对偶问题的多项式时间收敛性。文章的最后通过数值实验将该算法与Ye的解决线性规划的中心路径算法进行了比较。比较的结果显示新的算法从各个方面都要优于Ye的算法。     

电子回旋共振中和器内静磁场及微波电磁场的数值计算

为了研究电子回旋共振中和器内静磁场和微波电磁场的分布规律,设计合理的磁路结构以形成电子回旋共振区,并使微波强电场区与电子回旋共振区重合,采用有限元分析软件对中和器内的静磁场和微波电磁场进行了数值计算。计算结果表明:永磁体及磁轭的尺寸均影响电子回旋共振区的分布;天线伸入长度越长,微波电场越强。微波频率为4.2GHz时,六块相同的长12mm,宽8mm,高5mm的条形永磁铁与磁轭组成的磁路结构,可以产生合理的电子回旋共振区。L型天线伸入长度为5mm时微波强电场区可与电子回旋共振区重合。     

FM73M 胶膜及其与PMI 泡沫芯的胶接机理

采用DSC研究了不同升温速率下FM73M胶膜的固化反应特性,根据DSC曲线得到了胶膜的凝胶化温度和固化温度等工艺参数,建立了其固化动力学模型,确定胶膜的固化参数为(125±2)℃/90min.在此基础上,通过SEM研究了胶膜在PMI泡沫芯材内的分布以及界面结合状况(界面润温情况、气孔、缺陷),分析了胶膜与泡沫芯的胶接机理.     

Subsonic impulsively starting flow at a high angle of attack with shock wave and vortex interaction

Impulsively starting flow, by a sudden attainment of a large angle of attack, has been well studied for incompressible and supersonic flows, but less studied for subsonic flow. Recently, a preliminary numerical study for subsonic starting flow at a high angle of attack displays an advance of stall around a Mach number of 0.5, when compared to other Mach numbers. To see what happens in this special case, we conduct here in this paper a further study for this case, to display and analyze the full flow structures. We find that for a Mach number around 0.5, a local supersonic flow region repeatedly splits and merges, and a pair of left-going and right-going unsteady shock waves are embedded inside the leading edge vortex once it is sufficiently grown up and detached from the leading edge. The flow evolution during the formation of shock waves is displayed in detail. The reason for the formation of these shock waves is explained here using the Laval nozzle flow theory. The existence of this shock pair inside the vortex, for a Mach number only close to 0.5, may help the growing of the trailing edge vortex responsible for the advance of stall observed previously.