歼击机座舱维修工效定量评价技术研究及应用

为提高维修工作效率、减少维修差错、基于"人-机-环"理论,分析维修工效影响因素,引入德尔菲法确定维修工效评价指标体系,提出了基于灰色聚类模型的维修工效评价方法,实现了维修工效定性评价的定量化。结合某型歼击机维修工效核查数据,实例验证了评价指标及方法的有效性。     

Test sequencing problem arising at the design stage for reducing life cycle cost

Previous test sequencing algorithms only consider the execution cost of a test at the application stage. Due to the fact that the placement cost of some tests at the design stage is considerably high compared with the execution cost, the sequential diagnosis strategy obtained by previous methods is actually not optimal from the view of life cycle. In this paper, the test sequencing problem based on life cycle cost is presented. It is formulated as an optimization problem, which is non-deterministic polynomial-time hard (NP-hard). An algorithm and a strategy to improve its computational efficiency are proposed. The formulation and algorithms are tested on various simulated systems and comparisons are made with the extant test sequencing methods. Application on a pump rotational speed control (PRSC) system of a spacecraft is studied in detail. Both the simulation results and the real-world case application results suggest that the solution proposed in this paper can significantly reduce the life cycle cost of a sequential fault diagnosis strategy.     

基于ICAO起降模型的中国机场飞机排污计算研究

结合ICAO机场排放计算方法,在考虑3种主要气体污染物HC、CO和NOx的情况下,提出了适合中国机场飞机排放污染物的计算方法。该方法基于国际民航组织（ICAO）规定的标准起飞着陆（LTO）循环的模型,采用ICAO发动机排放数据库（ICAO aircraft engine emissions databank）,通过搜集中国民航机队的飞机／发动机配置信息及所列机场航班计划表,计算出机场污染物年排放量。     

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.     

Numerical study on similarity of plume infrared radiation between reduced-scale solid rocket motors

This study seeks to determine the similarities in plume radiation between reduced and full-scale solid rocket models in ground test conditions through investigation of flow and radiation for a series of scale ratios ranging from 0.1 to 1. The radiative transfer equation(RTE) considering gas and particle radiation in a non-uniform plume has been adopted and solved by the finite volume method(FVM) to compute the three dimensional, spectral and directional radiation of a plume in the infrared waveband 2–6 μm. Conditions at wavelengths 2.7 μm and 4.3 μm are discussed in detail, and ratios of plume radiation for reduced-scale through full-scale models are examined. This work shows that, with increasing scale ratio of a computed rocket motor, area of the hightemperature core increases as a 2 power function of the scale ratio, and the radiation intensity of the plume increases with 2–2.5 power of the scale ratio. The infrared radiation of plume gases shows a strong spectral dependency, while that of Al_2O_3 particles shows spectral continuity of gray media.Spectral radiation intensity of a computed solid rocket plume's high temperature core increases significantly in peak radiation spectra of plume gases CO and CO_2. Al_2O_3 particles are the major radiation component in a rocket plume. There is good similarity between contours of plume spectral radiance from different scale models of computed rockets, and there are two peak spectra of radiation intensity at wavebands 2.7–3.0 μm and 4.2–4.6 μm. Directed radiation intensity of the entire plume volume will rise with increasing elevation angle.     

Investigation of MHD power generation with supersonic non-equilibrium RF discharge

Magnetohydrodynamic (MHD) power generation with supersonic non-equilibrium plasma is demonstrated. Capacitively coupled radio frequency (RF) discharge (6 MHz, maximum continual power output of 200 W) was adopted to ionize the Mach number 3.5 (650 m/s), 0.023 kg/m3 airflow. In a MHD channel of 16 mm × 10 mm × 20 mm, MHD open voltage of 10 V is realized in the magnetic field of 1.25 T, and power of 0.12 mW is extracted steadily and con-tinuously in the magnetic field of 1 T. The reasons for limited power generation are proposed as:low conductivity of RF discharge; large touch resistance between MHD electrode and plasma;strong current eddies due to flow boundary layer. In addition, the cathode voltage fall is too low to have obvious effects on MHD power generation.     

空间平行机器与平行制造

近年来,随着空间技术的发展迅速,在可以预见的未来,在太空中作业和制造的需求必将变得越来越强烈.在太空环境中,对于智能、自主的要求越来越高.本文提出将平行机器、平行制造等和空间技术相结合,采用平行系统理论和方法,为实际的机器或者制造系统建立人工系统,在人工系统中进行计算实验得到合理的解决方案,通过平行执行指导实践.通过该方法,能够更好地应对太空中的不确定性和意外情况,尤其是通过平行增材制造实现快速、智能的补给和维修.     

索式火箭回收着陆系统缓冲装置设计与分析

针对索式火箭回收着陆系统中摩擦缓冲装置的缓冲能力和调节能力有限的问题,提出了一种基于最小二乘法和系统动力学特性的液压缓冲装置反问题设计方法。该方法通过对液压缓冲装置中控制阀凸轮外形和储能器初始压强的设计来调节着陆火箭运动学特性,使火箭按照特定的运动学特性在有限的缓冲位移内减速至静止稳定且缓冲加速度最小。对索式火箭回收着陆系统建立精准高效的多体动力学模型,并针对不同的工况进行仿真校验。仿真结果表明根据所提反问题设计方法设计的索式火箭回收着陆系统能够按照特定的运动学特性减速缓冲着陆火箭,具有较强的减速缓冲能力;针对不同质量和着陆位置偏差的着陆火箭,具有自动调整液压阻力保持火箭相同的运动学特性的能力。     

多向混杂纤维复合材料拉伸行为的研究

本文采用工程上常用的铺层角，保持铺层角度序列不变，通过改变混杂方式对多向混杂复合材料在拉伸载荷作用下的力学行为进行了实验分析研究，并与单向混杂纤维复合材料力学行为进行了比较，为混杂纤维复合材料准确地进行选材和材料设计，为混杂复合材料更广泛运用提供了理论基础。     

单板ATAC分布式处理机

本文介绍了应用技术公司(Applied Tecknologe)在一个单插入模块上制造硬件最少的300 kop 处理机,bk存储器和1553兼容远程终端的方法。这种应用方法是航空电子设备类型的分布式处理。完成对处理机设计的详细情况是根据减少硬件而对其性能影响最小这一点来进行描述的,制造单板存储器和1553接口的详细情况也一并介绍。