Numerical studies on supersonic spray combustion in high-temperature shear flows in a scramjet combustor

Numerical simulation is applied to detail the combustion characteristics of n-decane sprays in highly compressible vortices formed in a supersonic mixing layer. The multi-phase reacting flow is modeled, in which the shear flow is solved Eulerianly by means of direct numerical simulation, and the motions of individual sub-grid point-mass fuel droplets are tracked Lagrangianly. Spray combustion behaviors are studied under different ambient pressures. Results indicate that ignition kernels are formed at high-strain vortex braids, where the scalar dissipation rates are high. The flame kernels are then strongly strained, associated with the rotation of the shearing vortex, and propagate to envelop the local vortex. It is observed that the flammable mixtures entrained in the vortex are burned from the edge to the core of the vortex until the reactants are completely consumed. As the ambient pressure increases, the high-temperature region expands so that the behaviors of spray flames are strongly changed. An overall analysis of the combustion field indicates that the time-averaged temperature increases, and the fluctuating pressure decreases, resulting in a more stable spray combustion under higher pressures, primarily due to the acceleration of the chemical reaction.     

BTT导弹三维制导控制一体化建模与仿真

针对带有一定机动能力的飞行目标,结合弹目运动关系与导弹自身的动力学特性,给出了倾斜转弯(BTT)拦截导弹的俯仰、滚转、航向三通道独立制导控制一体化(IGC)设计。首先分别建立三通道数学模型,并给出了指令信号的计算形式,随后设计了基于动态面的IGC反步控制算法,最后在三维空间下进行目标拦截仿真验证。仿真结果表明,所建立的三通道模型能够充分描述目标与导弹之间的运动关系,设计的算法能够实现导弹对目标的精确拦截,且具有一定的抗机动能力。     

基于OpenGL的球形五杆并联机器人运动学仿真

在VC++环境下利用OpenGL实现了球形五杆并联机器人的实时运动仿真.利用键盘响应函数对并联机器人的运动进行实时控制,并可从不同视角和方位对运动情况进行观察.为原型样机的设计奠定了基础.     

知识基容错姿态控制系统

本文对知识基故障容错姿态控制系统加以简单的介绍。并对一类运载器提出实现它的方案设想。     

网格生成软件GRGES的设计与实现

首先,本文说明了研制网格生成软件对于促进计算流体力学研究和应用的重要意义。其次,本文论述了数值网格生成的基本概念和基本步骤,提出了网格生成软件GRGES的设计思想,简单介绍了GRGES的总体结构和五种网格生成方法。最后给出了三个网格生成算例,它们均可用于计算实际流场。     

管制员应该学会说“不”

在我们的生活中，大家都会遇到面对拒绝别人或被人拒绝的局面，对此你有什么感受呢？     

Preliminary observing achievements of supersoft X-ray detector and γ-ray detector onboard Shenzhou2

Preliminary observing achievements by the Super Soft X-ray Detector and the γ-ray Detector in the fields of cosmic gamma-ray bursts, solar X-ray, bursts and cosmic X-ray/γ-ray background radiation are summarized. The detectors are aboard the spacecraft Shenzhou-2 that was launched on 2001 January 10. The scientific mission and general situation of the instruments are briefly described.     

EKF和UKF在INS/GPS组合导航中的应用分析

扩展卡尔曼滤波(EKF)是在非线性系统中常用的一种滤波方法,Un-scented卡尔曼滤波(UKF)是一种新的非线性滤波算法,其主要特点是与EKF一样传递状态的前两阶矩,但不用计算Jacobian矩阵。将EKF和UKF分别应用到INS/GPS系统的滤波中,仿真结果表明UKF比EKF更适合于在INS/GPS系统中使用。     

用于连接与分离的非火工装置

文章主要介绍了几类航天上可用于连接与分离的非火工装置，如基于形状记忆合金（SMA）的连接释放装置，石蜡驱动器，低熔点材料释放装置。非火工装置具有冲击力小、无污染以及可重复使用等优点，非火工装置的这些优点正好是火工装置的不足之处，所以在不能使用火工装置的条件下可以考虑使用非火工装置。文章对接分离装置有一定的参考价值。