有人月球基地构建方案设想

有人月球基地的建设能将人类的活动区域扩展到月球,实现月球资源的深度开发和利用,服务于人类社会发展。中国开展月球基地建设,在技术上是空间站工程和载人登月工程的有效结合,也有利于其载人航天工程的可持续发展。文章针对有人月球基地的构建,将有人月球基地构建的基本途径分为刚性舱组装、柔性舱组装和月面建筑式三大类,并指出在月球基地发展的不同阶段构建途径的选择原则,再结合中国国情,提出了中国在有人月球基地发展初期的构建方案,最后对有人月球基地构建中的一些关键问题进行了分析总结。     

国外SAR卫星电源系统分析与启示

介绍了国外合成孔径雷达(SAR)卫星电源系统的特点,从SAR卫星成像模式多、峰值功率大、较大的载荷平台功率比以及脉冲功率工作等方面分析了其对电源系统设计的需求;介绍了欧洲和加拿大研制的Cosmo-Skymed卫星、TerraSAR-X卫星、Radarsat-2卫星、Sentinel-1卫星、EarthCARE卫星等的电源系统设计概况,对其电源系统拓扑、母线体制、太阳电池阵功率调节方式、锂离子蓄电池组配置等技术方案的特点进行了归纳总结,在此基础上提出了我国SAR卫星电源系统技术发展的建议。     

Calibration of a γ-Re_θ transition model and its validation in low-speed flows with high-order numerical method

Based on the Reynolds-averaged Navier–Stokes(RANS)equations and structured grid technology,the calibration and validation of γ-Re_θ transition model is preformed with fifth-order weighted compact nonlinear scheme(WCNS),and the purpose of the present work is to improve the numerical accuracy for aerodynamic characteristics simulation of low-speed flow with transition model on the basis of high-order numerical method study.Firstly,the empirical correlation functions involved in the γ-Re_θ transition model are modified and calibrated with experimental data of turbulent flat plates.Then,the grid convergence is studied on NLR-7301 two-element airfoil with the modified empirical correlation.At last,the modified empirical correlation is validated with NLR-7301 two-element airfoil and high-lift trapezoidal wing from transition location,velocity profile in boundary layer,surface pressure coefficient and aerodynamic characteristics.The numerical results illustrate that the numerical accuracy of transition length and skin friction behind transition location are improved with modified empirical correlation function,and obviously increases the numerical accuracy of aerodynamic characteristics prediction for typical transport configurations in low-speed range.     

A330头等舱座椅作动筒钢索失效修复方案

A330头等舱座椅作动筒钢索在长期使用中不可避免的出现不同程度的损坏和失效,造成高维修成本浪费,影响航线维护效率.分析和总结该型座椅钢索损坏根源,研究简洁、高效的应急修复方案,提高航线复杂座椅维修效率,避免航班延误,为旅客提供更好更优质的服务.     

基于迎风格式的三角翼涡流场数值模拟研究

采用基于有限体积方法的高精度迎风格式对层流N-S方程进行了数值模拟,研究了普通三角翼和双三角翼亚音速绕流的流场特性,并对双三角翼的几何外形、网格分布及远场边界对数值模拟的影响等问题进行了初步探讨.     

高精度差分格式在机翼分离流计算中的应用

用一个模型方程分析了边界层方程的数值稳定性 ,指出稳定性问题会随计算雷诺数减小而变得严重 ,因而对较低的Re数 ,计算分离边界层流动采用高阶精度差分格式十分必要。本文同时给出用四阶精度差分格式求解在流动分离情况下边界层方程的技术方法 ;对一个大展弦比后掠翼在攻角等于 1 4°时计算了机翼上表面的分离线 ,并与文献上公布的用别的测算方法测出结果做了比较 ,两者总体上符合良好     

无陀螺捷联惯导系统捷联方案研究

提出了无陀螺捷联惯导系统的惯性测量单元沿单轴相对载体旋转的捷联方案,对该方案进行了理论分析和数值仿真。结果表明,合理安装９ 个加速度计并适当选取捷联矩阵,则捷联方案无需高精度测量惯性测量单元相对载体旋转角速度也能大大提高载体角速度的精度。为满足相同的导航精度要求,本方案可降低对加速度计精度的要求约１０００ 倍。     

A 3rd Order WENO GLM-MHD Scheme for Magnetic Reconnection

A new numerical scheme of 3rd order Weighted Essentially Non-Oscillatory (WENO)type for 2.5D mixed GLM-MHD in Cartesian coordinates is proposed. The MHD equations are modified by combining the arguments as by Dellar and Dedner et al to couple the divergence constraint with the evolution equations using a Generalized Lagrange Multiplier (GLM). Moreover, the magnetohydrodynamic part of the GLM-MHD system is still in conservation form. Meanwhile, this method is very easy to add to an existing code since the underlying MHD solver does not have to be modified. To show the validation and capacity of its application to MHD problem modelling,interaction between a magnetosonic shock and a denser cloud and magnetic reconnection problems are used to verify this new MHD code. The numerical tests for 2D Orszag and Tang's MHD vortex,interaction between a magnetosonic shock and a denser cloud and magnetic reconnection problems show that the third order WENO MHD solvers are robust and yield reliable results by the new mixed GLM or the mixed EGLM correction here even if it can not be shown that how the divergence errors are transported as well as damped as done for one dimensional ideal MHD by Dedner et al.      

中层及低热层大气对局地时变热源的响应

采用二维交替方向隐格式(ADI),数值模拟了中高层大气对一个位于对流层高度范围的局地时变热源的响应．分析了这一过程中大气响应的能量密度,水平波数,垂直波数以及频率．模拟结果表明:响应波动携带能量向上传播,集中在较为狭窄的水平区域,该区域关于源的水平位置对称;相对于动量源驱动,热源的水平尺度对响应的水平波长决定性作用更加明显;对于高频振荡的热源,其响应的频率和源一致;响应的垂直波长(41 km)比源的垂直尺度(6 km)大得多．     

一种MWENO谱体积(SVMWENO5)格式

构造一种新的谱体积(spectral volume)格式来求解双曲型守恒律,记为SVMWENO5(Spectral Volume method byMulti-Weighted Essentially Non-Oscillatory)格式。其主要思想是:第一步,将空间计算区域划分为一系列单元,称为谱体积,等分每个谱体积为一些子单元,称为控制体积(control volume)。第二步,在谱体积内部采用类似MWENO5(Multi-Weighted Essentially Non-Oscillatory)的格式进行重构,而在谱体积的边界处采用传统WENO5格式进行处理。第三步,利用Runge-Kutta TVD离散方法对半离散格式进行时间离散,得到时空一致高精度全离散格式。最后,在文中给出几个经典数值算例用以验证本格式的计算能力。