尖前缘翼干扰区的壁面压力和热流率分布

本文给出Ｍ＿∞＝７．８和６．７２，Ｒｅ＝３．５×１０￣７／ｍ和５．４×１０￣７／ｍ气流绕迎角为２０°、３０°和３５°尖前缘翼运动时，平板锥型干扰区的壁面压力和热流率分布。结果表明：（１）平板锥型干扰区的特征几何尺度与无粘激波角β＿０和翼迎角α相关，而壁面压力和热流率的峰值与法向马赫数Ｍ＿ｎ相关。（２）翼面压力和热流率分布由于受拐角涡影响，前者在翼根部呈波谷状，而后者呈波峰状，影响尺度与翼前缘处来流边界层厚度有关。     

LU—TVD混合格式在跨声速NS方程计算中的应用

本文采用ＬＵ－ＳＳＯＲ隐式推进方法，并结合ＴＶＤ格式，计算了跨声速翼型的湍流解。文中采用Ｂａｌｄｗｉｎ－Ｌｏｍａｘ模型，对ＮＡＣＡ００１２翼型给出了马赫数０．７－０．９５的结果，并将部分计算结果与Ｈａｒｒｉｓ的实验作了比较，二者符合较好。     

LU－TVD混合格式在跨声速NS方程计算中的应用

本文采用ＬＵ－ＳＳＯＲ隐式推进方法，并结合ＴＶＤ格式，计算了跨声速翼型的湍流解。文中采用Ｂａｌｄｗｉｎ－Ｌｏｍａｘ模型，对ＮＡＣＡ００１２翼型给出了马赫数０．７～０．９５的结果，并将部分计算结果与Ｈａｒｒｉｓ的实验作了比较，二者符合较好。     

求解平面翼型亚,跨声速绕流的一个新方法

本文提出了求解平面翼型亚、跨声速绕流的一个新方法。引入流函数和Ｖｏｎ Ｍｉｓｅｓ变换后，亚、跨声速绕机翼无旋流动的基本方程组被化为以流线纵坐标ｙ为未知量的单个二阶偏微分方程－流线控制方程。并通过变换将物理平面上的无限域变为计算平面上有限的矩形域，而后在计算平面采用有限差分线松弛迭代法求解。作为算例，计算了对称翼型ＮＡＣＡ００１２－３４和非对称翼型ＮＡＣＡ４４１２的亚、跨声速有攻角绕流，所得数值结果     

用DSC曲线求EML─2，4固化环氧树脂的动力学参数

ＥＭＩ─２，４固化环氧Ｅ─５１的反应是由三个基本反应组成的复杂反应。本文用一张ＤＳＣ图，在二者质量比为０．０４２３６６时，求出其固化反应的表观动力学参数：ｎ＝０，Ｅ＝１．８１×１０￣５Ｊ／ｍｏｌ，Ａ＝３．４×１０￣２２ｓ￣－１。并发现二者质量比在２５％附近时．ＤＳＣ图出现双峰；固化剂用量不同时有不同的动力学参数。     

湍流度和雷诺数对附面层转捩位置的影响

对于层流翼型模型，当湍流度小于，当湍流度小于０．１％时，附面层转捩点位置没有明显影响，但其大于０．１％ 后则影响明显；而对ＮＡＣＡ００２４对称翼型西式春表面附面层转捩点位置不受湍流度的影响。     

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。     

测力法在翼型动态失速试验研究中的应用

本文就利用测力法对ＮＡＣＡ００１２翼型在振荡条件下的动态失速特性进行的测试作了简要介绍，阐述了测力法在翼型动态实验研究中的些特殊问题及其解决途径，并比较了两种实验研究方法的优缺点。     

表面吸气方法控制分离的数值模拟

本文使用数值模拟方法研究了吸气效应对分离的控制及增升作用。数值模拟采用的出发方程为可压流的Ｎ－Ｓ方程，格式为Ｂｅａｍ－ｗａｒｍｉｎｇ格式的改进型。主要研究结果表明：（１）在一定的吸气压强Ｃ＿（ｐｓ）范围内，绕圆柱流动的卡门涡街现象基本消失，流动从典型的非定常流趋于定常，圆柱的升阻比明显提高；（２）对于圆柱，吸气压强系数Ｃ＿（ｐｓ）＝－６时，综合效果比较好；（３）吸气孔位置开在圆柱上表面逆时针方向６０°时，圆柱的升阻比较高；（４）吸气可有效地提高翼型的升力     

用N－S方程计算翼型非定常粘性大攻角绕流

本文给出了用ＮＳ方程对翼型非定常粘性大攻角绕流的数值模拟。控制方程为二级时均可压缩完全ＮＳ方程；湍流模型采用双层代数涡粘性模型￣［１］。使用近似因式分解ＡＤＩ差分格式离散求解，网格是用保角变换方法生成的相对翼型固定的Ｃ型网格。本文给出两类典型非定常绕流数值模拟结果：翼型过失速常攻角周期流动和大攻角强迫俯仰谐振非定常绕流。并与国外的实验和计算结果进行了比较，表明了本方法准确、高效的特点。     

某任务计算机调试设备配套软件的设计与实现

简介了任务计算机调试设备配套软件在任务计算机仿真环境中的重要作用 ,对该软件设计方法和流程进行了详细的说明 ,主要介绍了VC ++6 .0环境下串行通信和显示控制软件的设计技术 ,并讨论了如何提高应用程序性能的途径。     

从科技论文的特点看科技论文的选题

本文论述了科技文的特点及选师原则。在特点方面主要就科技论文的科学性,创造性,理论性进行了阐述,在选题方面科技论文选题的客观需要与主条件进行阐述,旨在揭示科技论文的特点与课题选择之间的关系,从而了解其特点,并据此选题,写出符合要求的科技论文。     

Impact of a cavitation bubble on a wall

Impulse action of a cavitation bubble on a rigid wall is studied depending on the distance between them. We determine the distances at which the periphery pressure maximums on a wall are preserved as well as the distances at which these maximums exceed the water hammer pressure.     

Analysis of a redshifted plasma flow over a sunspot

The ultraviolet spectrum of a redshifted plasma flow appearing over a sunspot observed during the first flight of the High Resolution Telescope Spectrograph (HRTS I) is analysed, and interpreted as a radiatively cooling plasma. For most of the lines emitted from this plasma, the assumption of ionization equilibrium during the cooling is good. However for He II (and other ions with a single electron outside of closed shells), this is not the case. Integrating differential equations for the various ionization fractions of helium and the temperature allows an approximate determination of the abundance of helium relative to other elements whose lines appear in the spectrum of the plasma flow.     

Oscillations of a viscous liquid in a cylindrical container

The natural damped frequencies of a viscous liquid in a circular cylindrical container are obtained for slipping and anchored contact line at the container wall r = a. In addition the response to translational forced excitation has been determined. The results may also be applied to viscous liquid in a micro-gravity environment, as long as the contact angle of the liquid surface to the cylindrical container wall is in the vicinity of π/2, indicating, that the free liquid surface equilibrium position remains a plane surface. It could be found that there exists in contrast to frictionless liquid a small filling range, in which the liquid performs only an aperiodic motion. The adherence condition at the side wall was replaced by the somewhat weaker condition of an anchored contact line.     

Relativistic Energy-Momentum of a Body with a Finite Volume

The problem of energy-momentum in a body with a finite volume has been causing confusion in the theory of relativity, especially in relativistic thermodynamics. Its correct understanding has been given since the early years of relativity, however, erroneous misunderstandings are still found in papers and textbooks to this date. The present paper introduces a simple paradox to demonstrate the problem, and gives a brief review on a way to handle the energy-momentum correctly.     

某型弹用发动机火药吹转模拟试验

针对某型弹用发动机火药起动试验件起动试验要求,通过静态烟火试验数据确定火药起动模拟试验设备技术指标,在试验台上进行了高压冷吹和真实火药热吹起动试验,获取了两类试验下模拟转子的起动特性.试验结果表明:通过静态烟火试验和高压冷吹测得不同压力下空气流量、转速数据可以拟合出相关关系式,通过关系式能够预估燃气发生器所用火药量在热吹试验中转子可能最大转速,最后通过0.8kg真实火药热吹试验获取的最高转速与换算压力状态下的冷吹最高转速仅相差116r/min,进一步验证了试验和预估方法的有效性和准确性,可以减少或取消不同装药量火药在模拟转子上的吹转试验,减低在发动机上的试验安全风险,为在发动机上的应用奠定基础.      

Effect of a transverse plasma jet on a shock wave induced by a ramp

We conducted experiments in a wind tunnel with Mach number 2 to explore the evolution of a transverse plasma jet and its modification effect on a shock wave induced by a ramp with an angle of 24°. The transverse plasma jet was created by arc discharge in a small cylindrical cavity with a 2 mm diameter orifice. Three group tests with different actuator arrangements in the spanwise or streamwise direction upstream from the ramp were respectively studied to compare their disturbances to the shock wave. As shown by a time-resolved schlieren system, an unsteady motion of the shock wave by actuation was found: the shock wave was significantly modified by the plasma jet with an upstream motion and a reduced angle. Compared to spanwise actuation, a more intensive impact was obtained with two or three streamwise actuators working together. From shock wave structures, the control effect of the plasma jet on the shock motion based on a thermal effect, a potential cause of shock modification, was discussed. Furthermore, we performed a numerical simulation by using the Improved Delayed Detached Eddy Simulation(IDDES) method to simulate the evolution of the transverse plasma jet plume produced by two streamwise actuators. The results show that flow structures are similar to those identified in schlieren images. Two streamwise vortices were recognized, which indicates that the higher jet plume is the result of the overlap of two streamwise jets.     

The intersection of a Loxodrome with a great circle

The intersections of a loxodrome (rhumb line) and a great circle are of interest for some navigational problems, but a closed-form solution cannot be formulated. An algorithm is given for computing approximations to any desired degree of accuracy using Newton's method. By using the equatorial angle φ as an independent variable all solutions can be found rapidly using the modest computational capabilities of a personal computer     

直升机起落架的集成计算

直升机起落架常规计算包括停机状态计算及减缩质量计算、静态性能计算及主、尾起落架的着陆性能计算.要完成这些计算需要整机及起落架的诸多数据.在研制过程中,为了获得最优的设计,需要对起落架的各参数进行不断调整,对计算结果进行反复分析和比较,计算量较大,数据处理较为繁复耗时.详细阐述如何采用Excel和Matlab对起落架的常规计算进行集成.为完成一种直升机起落架的常规计算,采用该集成方法,编制了2000余行的M代码.在惠普Z800计算机平台下运行,耗时400余秒即可完成所有相关计算.输入输出的数据存储在同一Excel文件,文件中各项参数和计算结果数据可直接用于查阅、校对、分析,也可再编辑.