基于阻力分解策略的翼型阻力计算方法研究

研究并应用了基于翼型阻力分解策略的中场积分计算阻力的方法。中场积分方法是近年来提出的一种新的计算阻力的方法,方法将流场分为三个不同的区域：波阻区、型阻区、数值耗散区,通过对不同区域进行积分将阻力分解为波阻、型阻、数值耗散阻力。计算结果表明中场积分方法与传统的表面积分方法和远场积分方法相比,不仅可以将阻力分解成不同部分以便于进一步分析阻力产生机理,而且在计算中对网格量的要求较低,即使在网格量较小的情况下也能得到较精确的结果。     

基于数据库的新型航空发动机试验测控系统

简述了基于数据库的新型航空发动机试验测控系统的特点,介绍了一体化、信息化、网络化、智能化、标准化的航空发动机整机试验测控系统的设计思想、组成、结构和功能,为先进的新型航空发动机测控系统的应用进行了有意义地探索。     

一种新型垂直起降升力装置的气动特性分析与数值仿真

飞行器的垂直起降性能具有很高的军事价值和商业价值。但是目前垂直起降升力装置存在结构复杂,耗油量大,对地面热蚀严重等诸多问题,并且还限制了飞行器原有的性能,因此研究新型高效、简单实用的垂直起降升力装置迫在眉睫。本文基于二维N-S方程组和Spalart-Allmaras湍流模型,利用Fluent流场仿真软件,研究论证了一种...     

飞行器管理系统需求

飞行器管理系统(VMS)将飞行、推进控制与相关的公管系统综合.飞行器管理系统的概念为性能改善带来了巨大的好处,同时对可靠性、维修性和保障性有重大改善.未来高性能的飞机将具有多操纵面/效应器以保证机动性,利用飞行/推进综合控制实现性能收益.随着更多系统的参与,综合设计的难度会增加.为确保VMS的实际应用,需要明确其计算和...     

在轨服务的相对运动耦合动力学建模与分析

研究在轨服务航天器逼近与捕获目标航天器的相对轨道姿态耦合动力学建模问题。考虑航天器姿态与对接位置的运动耦合,建立目标运行在任意轨道下的相对轨道姿态耦合动力学模型,并对模型中的运动耦合进行深入分析。设计一种非线性的输出反馈姿态控制律,将建立耦合动力学模型与CW方程进行仿真比较,验证轨道与姿态的运动耦合对两航天器对接点之间相对位置的运动影响。     

基于单目视觉的三点测量滚转角方法

确定轴对称物体的滚转角是光学测量的重要内容,具有十分广泛的工程应用背景。本文提出一种单像机测量滚转角的新方法,通过3个控制点即可完全确定物体滚转角。仿真数据计算证明了该方法的正确性和可行性。     

SNMP协议在测控网远程监控中的应用研究

简要介绍了SNMP（简单网络管理协议）管理模型,基于测控设备C/S（客户/服务器）监控模式现状,分析了测控设备监控信息传输的特点,对现有监控信息传输协议与SNMP协议进行了研究,从传输可靠性、传输效率与协议操作应用等方面进行了比较,并开展了基于SNMP协议的远程监控信息传输试验。试验结果表明,基于SNMP协议可实现测控设备参数与状态监视信息的传输。     

Inversion of satellite gradiometry data using statistically modified integral formulas for local gravity field recovery

The satellite gravity gradiometric data can be used directly to recover the gravity anomaly at sea level using inversion of integral formulas. This approach suffers by the spatial truncation errors of the integrals, but these errors can be reduced by modifying the formulas. It allows us to consider smaller coverage of the satellite data over the region of recovery. In this study, we consider the second-order radial derivative (SORD) of disturbing potential (T_rr) and determine the gravity anomaly with a resolution of 1° × 1° at sea level by inverting the statistically modified version of SORD of extended Stokes’ formula. Also we investigate the effect of the spatial truncation error on the quality of inversion considering noise of T_rr. The numerical investigations show satisfactory results when the area of T_rr coverage is the same with that of the gravity anomaly and the integral formula is modified by the biased least-squares modification. The error of recovery will be about 6 mGal after removing the regularization bias in the presence of 1 mE noise in T_rr measured on the orbit.     

Characteristics of field line resonance type geomagnetic pulsations and variations of plasmaspheric plasma density distribution

The period of field line resonance (FLR) type geomagnetic pulsations depends on the length of the field line and on the plasma density in the inner magnetosphere (plasmasphere), where field lines are closed. Here as FLR period, the period belonging to the maximum occurrence frequency of the occurrence frequency spectrum (equivalent resonance curve) of pulsations has been considered. The resonance system may be replaced by an equivalent resonant circuit. The plasma density would correspond to the ohmic load. The plasma in the plasmasphere originates from the ionosphere, thus FLR period, occurrence frequency are also affected by the maximum electron density in the ionosphere. The FLR period has shown an enhancement with increasing F region electron density, while the occurrence frequency indicated diminishing trend (possible damping effect). Thus, the increased plasma density may be the cause of the decreased occurrence of FLR type pulsations in the winter months of solar activity maximum years (winter anomaly).     

CubeSail: A low cost CubeSat based solar sail demonstration mission

CubeSail is a nano-solar sail mission based on the 3U CubeSat standard, which is currently being designed and built at the Surrey Space Centre, University of Surrey. CubeSail will have a total mass of around 3 kg and will deploy a 5 × 5 m sail in low Earth orbit. The primary aim of the mission is to demonstrate the concept of solar sailing and end-of-life de-orbiting using the sail membrane as a drag-sail. The spacecraft will have a compact 3-axis stabilised attitude control system, which uses three magnetic torquers aligned with the spacecraft principle axis as well as a novel two-dimensional translation stage separating the spacecraft bus from the sail. CubeSail’s deployment mechanism consists of four novel booms and four-quadrant sail membranes. The proposed booms are made from tape-spring blades and will deploy the sail membrane from a 2U CubeSat standard structure. This paper presents a systems level overview of the CubeSat mission, focusing on the mission orbit and de-orbiting, in addition to the deployment, attitude control and the satellite bus.