Layer-oriented Element Integration Algorithm of Conformal Perfectly Matched Layer

As an efficient artificial truncating boundary condition, conformal perfectly matched layer (CPML) is a kind of multilayer anisotropic absorbing media. To reduce computing effort of CPML, this article proposes a layer-oriented element integration algorithm. In this algorithm, the relative dielectric constant and permeability are considered as constants for each the very thin monolayer of CPML, and the element integration of multilayer along the normal direction is substituted by the element integration of monolayer. The CPML is divided into multilayer elements, whose element matrixes are evaluated by monolayer integration. Numerical examples show that the layer-oriented element integration algorithm is reliable and the CPML formed with this algorithm possesses high-efficient absorbing performance.     

临近空间飞行器信息一体化初步设计

临近空间信息一体化体系的建设,是完备和闭合天地信息一体化网络的重要课题。简单介绍临近空间飞行器作为构建信息网络载体的优势,并简述课题研究的必要性以及国内外在该领域的发展现状与趋势。重点介绍临近空间信息一体化的基本体系与构成设想,分析构建临近空间信息一体化网络所面临的技术挑战。     

基于支板燃烧室的喷管化学非平衡效应

采用有限体积法全隐式格式和代用燃料C₁₂H₂₃的10组元13步化学反应Arrhenius有限速率模型研究煤油燃料超燃冲压发动机单边膨胀喷管(SERN, Single Expansion Ramp Nozzle)内的化学非平衡流动,通过建立支板燃烧室——喷管模型有效解决了单边膨胀喷管模型的"入口薄层"问题.计算结果表明,整个单边膨胀喷管内,流动呈现化学非平衡效应,喷管入口附近区域尤其显著;非平衡流动喷管性能明显高于冻结流动,随发动机当量混合比 ε增加,非平衡流动的喷管推力系数和升力系数相对冻结流动的百分比增量 δ不断升高,当 ε=0.8时,推力系数百分比增量 δ_CF达到9.41%,升力系数百分比增量 δ_CY达到16.39%,化学非平衡效应对煤油燃料超燃冲压发动机尾喷管性能的影响不可忽略.     

Development of a CELSS Experimental Facility

A CELSS Experimental Facility was developed two years ago. It contains a volume of about 40.0 m³ and a cultivating area of about 8.4 m²; its interior atmospheric parameters such as temperature, relative humidity, oxygen concentration, carbon dioxide concentration, total pressure, lighting intensity, photoperiod, water content in the growing-matrix, CO₂-added accumulative amount, O₂-released accumulative amount and ethylene concentration are all controlled and logged automatically and effectively; its growing system consists of two rows of racks along its left-and-right sides separately, each side holds two upper-and-lower layers, and the vertical distance of each growing bed can be adjusted automatically and independently; lighting sources consist of both red (95%) and blue (5%) light-emitting diodes (LED), and the average lighting intensity of each lamp bank at 20-cm distance position under it, reaches to 255.0 μmol m⁻² s⁻¹. After that, demonstrating tests were carried out and were finally followed by growing lettuce in the facility. The results showed that all subsystems operated well and all parameters were controlled automatically and efficiently. The lettuce plants in the system could grow much well. Successful development of this system laid a necessary foundation for future larger-scale studies on CELSS integration technique.     

直升机滑橇式起落架非线性有限元分析

本文采用MSC／NASTRAN分析软件对某直升机滑橇式起落架进行了弹塑性，大变形非线性分析，并与静力试验进行对比，理论计算与产测结果相当吻合，验证了理论分析的可靠性。     

树脂砂铸造镁合金阻燃技术研究

针对树脂砂铸造镁合金的燃烧问题,通过试验研究找出了采用树脂砂铸造镁合金过程中防止燃烧的途径,确定了阻燃涂料的成分配比,并采用该技术生产出了合格的舱体铸件。     

两种高精度高效率静气弹数据传递函数

遵循静气弹问题中气动/结构网格之间的数据传递要求,引入了基于径向基函数的流固耦合界面数据传递方法,确定了紧支半径的选取原则,并编制相应的计算程序。以M6机翼为例,将不同径向基函数的插值精度及计算效率进行比较,结果表明体样条（Volume Spline）函数和C2函数具有良好的插值精度和计算效率。这两种流固耦合界面数据传递方法非常适用于工程应用。     

基于分区簇头选择簇间多跳的路由协议

针对LEACH协议在能耗方面存在的不足,提出了一种分区簇头选择和簇间多跳的新协议。该协议分区域进行簇头选举、考虑了节点剩余能量、簇间采用多跳的方式传输数据。仿真结果表明,与LEACH协议相比,新协议有效的均衡了节点能耗,提高了能量利用率,延长了网络寿命。     

做好材料标准化工作保证产品降耗节支

分析111厂标准化工作中存在的问题,研究做好材料标准化工作的原则和主要内容,并对其工作提出改进措施。     

高精度喷嘴环斜锥孔加工专用铰刀的研究与应用

通过对某型号发动机喷嘴环斜锥孔加工铰刀的工艺研究与试验,确定了该刀具的基体材料、涂层材料(TiN)、涂层工艺(PVD)及设计参数,实现了该零件的批次性加工的实际状态与设计要求相一致的目标。进一步探寻了不锈钢斜锥孔高精度加工的特殊规律。