曲梁弹性波的传播

用特征线法求出了脉冲载荷作用下的控制曲梁运动的Ｍｏｒｌｅｙ方程的数值解，并用Ｐｌａｓｓ的直梁结果验证了曲率趋于零的极限情形，应用性地研究了曲梁中部受冲击载荷作用的弹性波传播问题，计算结果表明：该数值计算方法简便易行、效率高、有良好的收敛性和稳定性。     

飞机机翼表面水滴撞击特性计算

根据飞机防冰系统的研制需要，以机翼为对象，对水滴撞击特性的数值计算进行研究，建立了计算模型，研究了计算方法，用相应的计算程序，在广泛的飞行，气象及多种翼型条件下，对水滴撞击特性作了计算，计算结果与国外权威机构公布的数据相比吻合性好，给出了部分计算结果，并对水滴撞击特性计算的应用作了简要分析。     

一种基于星间方向观测的初轨计算方法

基于天基网空间监测的技术背景,用一已知轨道的天基观测平台对不明空间目标的方向观测,在定轨精度要求并不太高的要求下,研究了单颗卫星的天基平台定初轨的问题,并提出了一套基于此观测模型的中低轨空间目标的初轨计算方法。通过模拟生成测角资料对方法进行检验,计算结果显示方法在目前提出的定轨精度下是稳健可行的。     

界面位错的瞬态运动和界面裂纹的自相似扩展

本文首先利用Ｆｏｕｒｉｅｒ和Ｌａｐｌａｃｅ变换并结合Ｃａｇｎｉａｒｄ－ｄｅＨｏｏｐ反演方法求解了单个界面螺位错的瞬态运动问题，然后以单个位错由静止匀速运动的解作为基本解建立奇异积分方程求解了运动集中载荷作用下界面裂纹的反平面非对称自相似扩展，进一步由此解获得ｘｎ型载荷作用下界面裂纹自相似扩展的动应力强度因子     

Linear stability of ring systems around oblate central masses

In this paper, we consider the stability of a ring of bodies of equal mass uniformly distributed around a large oblate central mass. The purpose of this and previous papers is to shed light on the stability of Saturn’s rings. Previous papers have been limited by the assumptions that (1) all ring bodies are at the same distance from the central body, (2) the central body acts like a point mass (i.e., is a perfect sphere), and (3) the ring bodies all have the same mass and are evenly spaced around the ring. The third limitation is probably the least important; as long as there are a large number of masses and the mass distribution is approximately uniform then the system should behave as a system of equally-spaced, equal-mass bodies. The first main purpose of this paper is to remove the second limitation. But, the paper also aims to address limitation (1). Recent computer simulations of single-ring systems have shown that the threshold for stability, as determined by a linear stability analysis, matches precisely the stability threshold predicted by simulation. In other words, a linear stability analysis while presumably just a mathematical abstraction actually tells us something quite real. Furthermore, simulations of multi-ring systems suggest that instability comes from azimuthal perturbations; small azimuthal changes are more destabilizing that small radial perturbations. Hence, in this paper, we also consider the situation where the central body consists not just of an oblate central mass but also incorporates a flat ring representing in aggregate all ring bodies at radii other than the one under consideration. The central oblate body together with a flat ring is modeled simply by introducing two oblateness terms to the gravitational potential associated with the central mass. The subsequent analysis is almost identical to the case of a single oblateness term. For Saturn, the oblateness of the central mass is six orders of magnitude more significant than the rings at other radii as a destabilizing influence.     

Deployment of a lander on the binary asteroid (175706) 1996 FG3, potential target of the european MarcoPolo-R sample return mission

The idea of deploying a lander on the secondary body of the binary primitive asteroid (175706) 1996 FG3 is investigated. 1996 FG3 is the backup target of the European sample return space mission MarcoPolo-R under assessment study at the European Space Agency in the framework of the M3 Medium-Class mission competition. The launch will take place in 2022–2024, depending on its selection at the end of 2013. A lander is indicated as an optional payload, depending on mass availability on the spacecraft. Obviously, the possible complexity of a lander deployment is also an important parameter to take into account. Here we demonstrate that, considering worst case scenarios and low requirements on the spacecraft GNC and deployment mechanism, the operations are easy to implement and safe for the main spacecraft. The concept of operations is to deploy a light lander from the L₂ Lagrange point of the binary system, on a ballistic trajectory that will impact the secondary asteroid. The fundamental principles of this strategy are briefly presented and a detailed model of 1996 FG3 is considered, to which the strategy is applied. We show that the deployment is successful in 99.94% of cases.     

轻型飞机燃油油量表指示器的原理设计和定量分析

燃油油量的测量，方法很多。本文首先论述了浮子电位器式传感器与电阻电桥相匹配的测量原理以及计算方法，     

SEL587差动保护装置原理与技术应用

分析SEL587差动保护装置的基本原理,阐述零序电流的影响。应用情况表明,该装置运行可靠,动作灵敏。     

纳秒脉冲等离子体气动激励数值仿真

从纳秒脉冲等离子体气动激励对流场的作用机理出发,将其对流场的作用等效为热源对流场的快速加热,建立了纳秒脉冲等离子体气动激励的空气动力学模型.应用模型计算了单次纳秒脉冲等离子体气动激励下静止流场的响应,计算结果表明:纳秒脉冲等离子体气动激励可在静止流场中形成一个高温升压升区(716K,225.95kPa)和一个低温升压升区(380K,131.7kPa),分别可诱导一强一弱两道压缩波,压缩波后各有一道稀疏波.压缩波与稀疏波同速向外传播,传播速度开始较大(大于400m/s),随着逐渐向外传播,其传播速度逐渐减小(357m/s).压缩波经过的区域可诱导局部速度,初期诱导的局部速度较大,在激励器切向和法向可诱导60m/s以上的局部速度,随着压缩波的衰减,诱导局部速度的能力减弱,最大可诱导10m/s左右的局部速度.      

低雷诺数下翼面局部振动增升机理研究

采用计算流体力学(CFD)方法研究低雷诺数下翼面局部振动对翼型气动特性及其流动特征的影响规律。建立局部振动激励的力学模型,并采用任意拉格朗日-欧拉坐标系下的特征线有限元(ALE-CBS)方法对局部振动激励下翼型绕流问题进行模拟,分析局部振动对非定常流动演化的影响规律,揭示其增升机理。研究结果表明:翼面局部变形的增加会有效降低翼型上表面的前缘压力;非定常流动分离中旋涡之间的距离及其演化频率与振动频率的关系是影响翼型翼面局部振动增升效果的重要因素。当流场主频率与振动频率相同,次要频率为主频率的2倍,即发生锁频时,翼面振动产生的移动分离泡能够使分离区从主流获取更多的能量,使翼型上表面保持较低的压力,有效提高翼型升力。