基于DEAHP的管制运行效率评价模型

管制运行效率是综合衡量空管系统总体运行状态的重要指标。针对我国空中交通拥堵状况,为了减少航班延误,必须从提高管制运行效率入手,分析管制间隔运用现状及其与其他影响空管运行效率的关键指标的关系,基于管制间隔运用现状建立了管制运行效率的评估指标体系及模型。首次将含约束锥的DEA模型（ DEAHP）引入到管制运行效率评价中,克服了传统DEA模型的缺点。并以北京区管中心为例,验证了模型的有效性。     

风挡防冰热性能分析工程模型的建立和验证

为表明飞行条件和结冰条件所有组合下防冰能力是足够的,分析了风挡的设计需求和流场特性,建立了理论上保守的工程模型,确定了模型的关键系数;通过飞行试验数据修正了关键系数并验证了模型;该模型能够便捷地使用常用的编程语言甚至EXCEL内置函数实现对所有组合状态的性能分析,其结果能够支持适航取证及CFD计算状态筛选。     

基于GPM的高超声速飞行器再入轨迹优化

为保证高超声速飞行器具有最大再入距离,应用高斯伪谱方法求取了存在路径约束及终端约束的飞行器最优再入轨迹。首先选取迎角及倾斜角作为最优控制量,并分析再入轨迹的最优控制模型;然后应用高斯伪谱方法将最优控制问题离散成非线性规划问题,并采用SNOPT软件包对非线性问题进行求解,得到最优轨迹。通过仿真证明了该方法求得的最优轨迹对初始值不敏感,且具有良好的实时性。     

民用飞机风挡表面对流换热系数的校核

适航条款要求在结冰条件下,应确保风挡表面不能结冰,防止影响飞行员视界。因此应确定结冰条件下具有足够的电加热功率使风挡表面温度高于冰点(零度),而影响加热功率的关键因素是外表面的对流换热系数。为了获得准确的对流换热系数,在低速风洞中测量了不同工况下风挡表面对流换热系数,并利用CFD方法建立了一个仿真风洞模型,计算试验工况下的风挡表面对流换热系数,通过测量值来校核CFD的计算值,获得一个修正方法,最终使用这个修正方法计算获得其他工况下的对流换热系数。     

70kN载荷应变天平校准系统研制进展

研制了70kN量级的应变天平校准系统,以满足2m量级高速风洞测力试验天平的静态校准需求。70kN载荷应变天平校准系统基于传统的单元校准方法,采用四自由度复位式体轴系自动校准方案,加载力源为标准砝码,采用砝码独立控制技术的自动加载装置实现天平校准载荷的自动加载。砝码产生的重力通过双十字铰链施力定位装置和刚性加载头准确地传递到天平上,无间隙复位传动机构可以保证天平的精确复位。建成后的校准系统可满足20~70kN量程范围的杆式天平和环式天平等不同类型天平的校准需求。     

孕育铸铁链轮激光表面强化

应用激光束对孕育铸铁(HT300)链轮表面进行激光淬火处理,可增强链轮的抗磨损性能,提高链轮表面硬度,从而达到延长寿命的目的。试验结果表明,对孕育铸铁链轮进行激光淬火强化处理较一般淬火工艺简单,耐磨性能及硬度均可完全满足零件的工作条件及要求。     

激光深熔焊熔池动力学特性研究

分析了激光深熔焊熔池流体流动的热边界层和固-液界面边界层的特点,研究了小孔内壁金属蒸发以及小孔上方等离子焰对熔池流体流动的作用,在考虑入射激光功率密度以及流体粘度变化对激光焊接熔池影响的基础上,建立了具有激光深熔焊熔池特点的熔池动力学数学模型的框架,指明了激光小孔焊熔池流动模拟的发展方向。     

RTM酚醛树脂研究进展

根据国内外酚醛树脂的研究现状，从树脂的合成、主要特征、工艺和性能等方面介绍了几种RTM酚醛树脂——酚三嗪树脂、苯并噁嗪树脂、双马改性酚醛树脂和PAA树脂，同时指出了各种树脂的优缺点。     

验前大容量仿真信息“淹没”现场小子样试验信息问题

在运用Bayes方法对武器系统进行鉴定的过程中，仿真信息作为验前信息使用一直是一个有争议的问题。本文给出了验前子样可信度的定义及相应的计算方法，在分析了大量仿真信息“淹没”小子样现场试验信息这一现象的基础上，将验前信息的可信度引入统计推断，较好地解决了仿真信息在试验鉴定中的应用问题。     

Optimal assimilation for ionospheric weather – Theoretical aspect

Observation, specification and prediction of ionospheric weather are the key scientific pursuits of space physicists, which largely based on an optimal assimilation system. The optimal assimilation system, or commonly called data assimilation system, consists of dynamic process, observation system and optimal estimation procedure. We attempt to give a complete framework in this paper under which the data assimilation procedure carries through. We discuss some crucial issues of data assimilation as follows: modeling a dynamic system for ionospheric weather; state estimation for static or steady system in sense of optimization and likelihood; state and its uncertainty estimation for dynamic process. Meanwhile we also discuss briefly the observability of an observation system; system parameter identification. Some data assimilation procedures existed at present are reviewed in the framework of this paper. As an example, a second order dynamic system is discussed in more detail to illustrate the specific optimal assimilation procedure, ranging from modeling the system, state and its uncertainty calculation, to the quantitatively integration of dynamic law, measurement to significantly reduce the estimation error. The analysis shows that the optimal assimilation model, with mathematical core of optimal estimation, differs from the theoretical, empirical and semi-empirical models in assimilating measured data, being constrained by physical law and being optimized respectively. The data assimilation technique, due to its optimization and integration feature, could obtain better accurate results than those obtained by dynamic process, measurement or their statistical analysis alone. The model based on optimal assimilation meets well with the criterion of the model or algorithm assessment by ‘space weather metrics’. More attention for optimal assimilation procedure creation should be paid to transition matrix finding, which is usually not easy for practical space weather system. High performance computing hardware and software studies should be promoted further so as to meet the requirement of large storage and extensive computation in the optimal estimation. The discussion in this paper is appropriate for the static or steady state or transition process of dynamic system. Many phenomena in space environment are unstable and chaos. So space environment study should include and integrate these two branches of learning. This revised version was published online in August 2006 with corrections to the Cover Date.