飞机激光雷达散射截面测量与分析

飞机激光雷达散射截面的测量,对于研究飞机激光散射特性以及评估探测系统至关重要.本文介绍了飞机激光雷达散射截面测量理论,设计了飞机激光雷达散射截面测量装置和测量方法,并通过实验验证了该装置与测量方法.在全尺寸真实飞机试验与测量过程中,通过对原始数据高斯补偿与背景修正,获得了误差小于7%的飞机激光雷达散射截面数据.实验结果表明,本文提出的飞机激光雷达散射截面测量与分析方法是正确的和有效的.     

基于战役的多机种战伤备件需求模型

为了合理储备战时航材备件,通过分析战时故障备件的需求特点,改进了传统的单机故障备件需求模型.根据多机种协同作战任务的不同,引入备件工作运行比的概念,建立了基于作战任务的多机种故障备件需求模型.为解决多机种协同作战时的保障资源配置问题提供了思路和方法.     

飞机发动机进口流场综合压力畸变指数W的实时采集处理软件实现技术

简要介绍了一个改进的飞机发动机进口流场压力畸变指数测量系统的硬件体系,重点讨论了系统的软件实现方法及其部分关键技术,其中用扩展内存技术解决了实时大容量稳态数据的长时间存储问题,使用此系统对飞机发动机进口流场综合压力畸变指数Ｗ进行了测量和处理     

Verteilungsmessungen zur Prüfung von Pflanzenschutzgeräten

Zur Prüfung der verteilungsqualität der von Bodengeräten und Flugzeugen ausgebrachten Ölspriäh- und Stäubenmittel wurden Markierungsverfahren mit₁₉₈ Au entwickelt. Gemessen werden Blätter aus dem Pflanzenbestand oder Blankfilm, der auf der Fläche aufgespannt wurde, mit Hilfe einer Automatik. Die Methode ist Bestandteil der Prüfung von Pflanzenschutzgeräten.     

利用荧光法检测磷酸酯液压油的泄漏

提出了一种检测飞机液压油泄漏的方法--荧光法,以美孚磷酸酯液压油为例,实验验证了荧光法检测磷酸酯液压油泄漏的可行性。采用LS-55型荧光分光光度计以及实验室搭建系统对HyJet Ⅴ磷酸酯液压油以及Jet Oil Ⅱ、2197润滑油的荧光特性进行了分析。研究结果表明,可以用不同荧光发射光谱峰值来区分三种油,荧光法检测磷酸酯液压油泄漏是可行的。该技术可实现对飞机液压油泄漏的实时、在线、现场测量。     

Minimum-time 180° turns of aircraft

Three-dimensional minimum-time 180° turns of a fighter aircraft are computed for several initial velocitiesV ₀ and altitudesh ₀. It is shown that the optimum turns consist of split -S maneuvers forV ₀≦V ₁₀, three-dimensional maneuvers forV ₁₀<V ₀<V ₂₀, and half-loops forV ₀≧V ₂₀, withV ₁₀,V ₂₀ being functions of altitude or thrust/weight ratio.     

Optimization of an Active Noise Control System Inside an Aircraft, Based on the Simultaneous Optimal Positioning of Microphones and Speakers, with the Use of a Genetic Algorithm

In the last decade, Active Noise Control (ANC) has become a very popular technique for controlling low-frequency noise. The increase in its popularity is a consequence of the rapid development in the fields of computers in general, and more specifically in digital signal processing boards. ANC systems are application specific and therefore they should be optimally designed for each application. Even though the physical background of the ANC systems is well known and understood, efficient tools for the optimization of the sensor and actuator configurations of the ANC system, based on classical optimization methods, do not exist. This is due to the nature of the problem that allows the calculation of the effect of the ANC system only when the sensor and actuator configurations are specified. An additional difficulty in this problem is that the sensor and the actuator configurations cannot be optimized independently, since the effect of the ANC system directly depends on the combined sensor and actuator configuration. For the solution of this problem several other optimization techniques were applied, such as simulated annealing for example. In this paper the successful application of a Genetic Algorithm, an optimization technique that belongs to the broad class of evolutionary algorithms, is presented. The results obtained from the application of the GA are very promising. The GA was able to identify various configurations that achieved a reduction of 6.3 dBs to 6.5 dBs, which corresponds to an actual reduction of 50% of the initial acoustic pressure.     

某军用机场飞机噪声暴露的模化研究

针对军用机场飞机飞行训练方式复杂多变,飞机噪声影响存在范围大、不均匀及单次事件噪声突出的特点,本文结合某军用机场实地调研测试资料,综合考察了现行评价指标对该机场飞机噪声暴露的模化效果,指出了现行指标在反映军用飞机瞬时噪声和高峰时段噪声对人的冲击影响方面的不足,提出了相应的改进措施建议,给出了高峰时段LWECPN和最大A声级LAmax两个改进指标,并分析确立了各评价指标的标准限值。最后结合调研机场的数据资料对评价指标的有效性进行了验证。论文的研究成果对军用机场飞机噪声暴露的拓展研究和通用评价指标体系的构建具有很好的参考作用。     

微小型球形飞行器飞行控制系统设计

根据微小型球形飞行器的结构特点和工作原理,设计了一套基于ARM Cortex-M3 STM32F103RBT6微控制器的飞行控制系统,进行了主要模块的功能设计与性能分析,给出了研究结论与选型依据,还设计并完成了姿态传感器两轴转台实验和飞行器室内飞行试验。测试结果表明,该控制系统的姿态传感器姿态测量精度高,能够为飞行控制提供姿态参考信息;飞行器能够圆满实现空中悬停、低空机动等飞行动作,且空中飞行姿态稳定、实时、可靠。该飞行控制系统功能可靠、性能稳定,能够较好地满足微小型球形飞行器的飞行控制要求,具有一定的实用性与扩展性。     

Study on Heat Transfer Performance of Skin Heat Exchanger

Cooling technology is facing new challenges with the increase of electronic equipment power onboard aircraft. The traditional heat sink based on high-altitude bleed air does not satisfy this increase of cooling demands. In this article, an air/air-type skin heat exchanger is studied for cooling aircraft electronic equipment. It uses outside high-altitude cold air rather than bleed air as a heat sink. This cooling technology can effectively remove the heat load of high-power electronic devices without greatly increasing aircraft performance penalty. To assess its high-altitude heat transfer performance, an experimental prototype was designed and made. Some experiments were conducted on a ground experimental test. The heat transfer criteria formulas were obtained for both the side air in the skin heat exchanger and its convective heat transfer coefficients. Based on these experimental analyses, the heat transfer performances of the skin heat exchanger in a high-altitude cruise condition are deduced when it is assumed to be installed at an unfavorable position and a favorable position, separately. This work tries to provide a technical support for its future onboard application.