航天分散热源控温用环路热管设计及飞行应用

为满足国家高分专项遥感卫星焦面电路的力热稳定性要求,提出并设计了一种用于分散式热源精密控温的改进型环路热管(LHP),既实现了狭小空间内对多片焦面CCD器件的统一恒温控制,又兼顾了焦面结构与卫星舱板间的力学解耦功能。地面测试结果表明:该LHP的热负载携带能力及对分散式热源的精确控温效果良好。2015年9月份,将该控温用LHP成功应用于GF-9卫星遥感器CCD器件的飞行控温,截止目前已在轨运行超60个月,受控的4片CCD器件温度稳定性达±0.7℃/年,证明了该控温用LHP设计方法的正确性及工程可实现性,同时实现了我国自研控温用LHP在航天微重力环境下的首次长寿命应用。本文LHP的设计方法和在轨飞行数据,对后续LHP在航天热控领域的应用具有一定的参考价值。

结构状态监测技术飞行应用的若干问题与关键技术

在民机结构设计、制造、飞行及地面维护的全生命周期,特别是在地面试验与飞行测试中,越来越需要通过采集与处理能反映结构状态的数据,对结构状态进行实时监测与分析。为了推进结构状态监测技术的应用,本文对传感器、黏结剂、线缆、接头和设备的设计及安装等方面进行了研究,分析了系统的性能、环境、安全性、可靠性和维修性要求,提出了实现飞行应用所需要完成的工作及部分应对策略,以期解决结构状态监测系统在民机应用方面的问题,推动其在飞行测试及型号中的应用。

路桥工程的北斗导航系统的飞行器应用研究

无人机是一种无人驾驶,依靠无线电遥控或飞行程序操作的飞行器,能够从事一些不方便载人的复杂任务。近些年,无人机被广泛应用于军事和民用领域,给人们的生活带来了意想不到的作用。在城市交通中,道路和桥梁一直起到维持交通运输的作用,为城市经济的发展做出了不可替代的贡献。但进行道桥工程时,维修和养护等问题的排查还在使用人工手段,不仅没有实时性,而且工作效率低,投入成本高。如果将无人机飞行器运用到路桥工程中,可以作为技术上的强大助力。本文分析了北斗导航系统飞行器的相关设计,阐述了飞行器在路桥应用中存在的问题和解决方案,希望能够为无人机飞行器在路桥工程中的应用提供参考。

四旋翼飞行器综述

随着无人机技术的发展,四旋翼飞行器逐渐受到人们的关注,成为了研究的热点问题。本文以四旋翼飞行器为对象介绍了其特点、飞行器的结构、应用领域以及其研究领域和主要研究方向,为后续工作的展开打下了基础。

离子推力器非预期电击穿特性及其主要影响因素对比研究

采用对比分析方法研究空间与地面、不同工况、不同累计工作时间段的离子推力器非预期电击穿特性变化,获得了离子推力器击穿频次与其主要影响因素之间的关联性。研究结果表明:在地面试验和空间飞行的全任务周期中,推力器击穿频次都呈现出早期较高、然后快速降低并保持长期稳定的基本特点;空间飞行应用中的平均击穿频次普遍比地面试验中的低1~2个数量级,其根本原因在于地面试验中不可避免地存在推力器暴露于大气、试验舱背溅射污染等诱发因素;栅极材料、电场强度、束流密度、溅射沉积物是决定推力器非预期电击穿本质特性的主要因素;击穿引发的阴极或放电室熄弧现象值得特别关注并应避免其发生。

Progress of Chinese“Dove”and Future Studies on Flight Mechanism of Birds and Application System

This paper introduces the Chinese"Dove"——A practical application system of bird-mimetic air vehicles developed for more than a decade by the Institute of Flight Vehicle Innovation of Northwest Polytechnic University(NWPU)in China.Firstly,the main components,flight capability and flight verification of the Chinese"Dove"are presented.Then,the methods for the aerodynamic simulation and wind tunnel experiments are put forward.Secondly,the design of high-lift and high-thrust flexible flapping wings,a series of flapping mechanisms,gust-resistance layout and micro flight control/navigation system are presented.Some future studies on the application system of bionic micro air vehicles are given,including observation of natural flight creatures,aerodynamics in flight,mechanical and new material driving systems,structural mechanics,flight mechanics,and the information perception and intelligent decision-making control,which are related to research of flight bioinformatic perception and brain science.Finally,some application examples of complex flapping movements,active/passive deformation of bird wings,new low-energy motion-driven system,bionic intelligent decision-making and control/navigation are discussed.

Development and Missions of Unmanned Surface Vehicle

The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.

Designing similarity measurement with distance measure and application on laterally directional mode flight test

Similarity measure construction has been proposed as fault detection of flight test method in order to obtain the primary control surface stuck and the combination stuck of primary control.Similarity measures were obtained through analyzing the certainty and uncertainty of fuzzy membership functions,which were designed based on well-known Hamming distance.It was applied to the fault detection of primary control surface stuck of uninhabited aerial vehicle(UAV).At post-failure control surface,if the UAV is controllable and trimmable using other control surfaces,the UAV is able to fly or return to the safety region through reconfiguration of flight control system.To detect the fault,similarity measure computations were carried out.This result could be applicable with the real-time parameter estimation method.By monitoring the value of coefficients due to the control surface deviation,it becomes aware that the control surface fault occurs or not.The control surface stuck position and value were separated by comparing the trim value with the reference value.This is the advantage of increasing in reliability without adding sensors or with additional low cost.

Establishment and application of a multiplex genetic mutation-detection method of lung cancer based on MassARRAY platform

Objective: This study aims to establish a method for highly parallel multiplexed detection of genetic mutations in Chinese lung cancer samples through Agena i PLEX chemistry and matrix-assisted laser desorption ionization time-of-flight analysis on Mass ARRAY mass spectrometry platform.Methods: We reviewed the related literature and data on lung cancer treatments. We also identified 99 mutation hot spots in 13 target genes closely related to the pathogenesis, drug resistance, and metastasis of lung cancer. A total of 297 primers, composed of99 paired forward and reverse amplification primers and 99 matched extension primers, were designed using Assay Design software. The detection method was established by analyzing eight cell lines and six lung cancer specimens. The proposed method was then validated through comparisons by using a Lung Carta^(TM) kit. The sensitivity and specificity of the proposed method were evaluated by directly sequencing EGFR and KRAS genes in 100 lung cancer cases.Results: The proposed method was able to detect multiplex genetic mutations in lung cancer cell lines. This finding was consistent with the observations on previously reported mutations. The proposed method can also detect such mutations in clinical lung cancer specimens. This result was consistent with the observations with Lung Carta^(TM) kit. However, an FGFR2 mutation was detected only through the proposed method. The measured sensitivity and specificity were 100% and 96.3%, respectively.Conclusions: The proposed Mass ARRAY technology-based multiplex method can detect genetic mutations in Chinese lung cancer patients. Therefore, the proposed method can be applied to detect mutations in other cancer tissues.

Application of high temperature heat pipe in hypersonic vehicles thermal protection

In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal protection were introduced. The methods of numerical simulation, theory analysis and experiment research were utilized to analyze the frozen start-up and steady state characteristic of the heat pipe as well as the machining improvement for fabricating irregularly shaped heat pipe which is suitable for leading edge of hypersonic vehicles. The results indicate that the frozen start-up time of heat pipe is long （10 min） and there exists large temperature difference along the heat pipe （47 ℃/cm）, but the heat pipe can reduce the temperature in stagnation area of hypersonic vehicles from 1 926 to 982 ℃ and work normally during 1 000-1 200℃. How to improve the maximum heat transfer capability and reduce the time needed for start-up from frozen state of the heat pipe by optimizing thermostructure such as designing of a novel wick with high performance is the key point in hypersonic vehicles thermal protection of heat pipe.

Reconfigurable-System-on-Chip Implementation of Data Processing Units for Space Applications

Application-specific data processing units (DPUs) are commonly adopted for operational control and data processing in space missions. To overcome the limitations of traditional radiation-hardened or fully commercial design approaches, a reconfigurable-system-on-chip (RSoC) solution based on state-of-the-art FPGA is introduced. The flexibility and reliability of this approach are outlined, and the requirements for an enhanced RSoC design with in-flight reconfigurability for space applications are presented. This design has been demonstrated as an on-board computer prototype, providing an in-flight reconfigurable DPU design approach using integrated hardwired processors.

Recent Advances in the Theoretical and Applied Study on Compressible Turbulent Flow over Aerospace Vehicles

This paper focused on the fundamental and applied research of turbulent flows encountered in the hypersonic flight of aerospace vehicles,which take place in the boundary layer and mixing layer.As to the plate boundary layer,LES approach has been used to simulate the flows over compression corners and incident shock waves,revealing that turbulent flows would significantly inhibit the boundary layer separation caused by shock wave-boundary layer interaction(SWBLI).The boundary layer transition over a circular cone has been analyzed through stability analysis and wind-tunnel test,by which the angle-of-attack effect in case of small angle of attack has been studied.Non-linear evolution process and secondary instability structure in the supersonic mixing layer(Mc=0.5) were initially figured out through the study of mixing layer,and knowledge of the flow control mechanism of the boundary layer and mixing enhancement mechanism of the mixing layer has been obtained through this research.Artificial boundary-layer transition technique based on subharmonic resonance has been proposed and applied to the flow control in a scramjet inlet,inhibiting the flow separation of the boundary layer while improving the inlet performance.To guarantee the mixing of kerosene and supersonic airflow in the scramjet combustor,the mixing enhancement method based on subharmonic resonance has been adopted and a concept of combustor with smooth wall and low internal drag has been proposed for ignition and stable combustion.Finally,future turbulence research and technological development of aerospace vehicles is predicted.

Application of piezoelectric fiber composite actuator to aircraft wing for aerodynamic performance improvement

The application of actuator made of piezoelectric material,particularly the advanced piezoelectric fiber composite due to the rapid development of smart materials and structures and active control technology in aviation and aerospace industry,to aircraft for performance enhancements such as flight control,aerodynamic force optimization,structure weight reduction,and overall aircraft design represents a new challenge to researches.It is considered as one of the key technologies for developing future flight vehicle.An approach with virtual control surface instead of conventional control surface to control aerodynamic force distribution and flight performance by use of piezoelectric fiber composite actuators distributed on wing surface is presented here.Particularly,the design and implementation of increasing lift force,providing roll maneuver,decreasing induced drag and wing root moment in different flight environments by the same structure control platform are studied.The control effect and sensitivity are examined quantitatively.Generally speaking,better control effect can be obtained by making better use of aeroelastic character to enlarge the actuation strain produced by piezoelectric material.

THE FEASIBILITY OF USING VERTICAL-LOOKING RADAR TO MONITOR THE MIGRATION OF BROWN PLANTHOPPER AND OTHER INSECT PESTS OF RICE IN CHINA

The recent development of automatically operating, inexpensive vertical-looking radar (VLR) for entomological purposes has made it practical to carry out routine, automated monitoring of insect aerial migration throughout the year. In this paper we investigate whether such radars might have a role in monitoring and forecasting schemes designed to improve the management of the Brown Planthopper (BPH), Nilaparvata lugens, and of associated rice pest species in China. A survey of the literature revealed that these insects typically migrate at altitudes between 300 to 2 000 m above ground level, but calculations based on BPH radar scattering cross-sections indicated that the maximum altitude at which they individually produce signals analysable by current VLRs is only～240 m. We also show that coverage over most of the flight altitudes of BPH could be achieved by building a VLR using a wavelength of 8.8 mm instead of the 3.2 cm of existing VLR, but that such a radar would be expensive to build and to operate. We suggest that a more practical solution would be to use a 3.2 cm VLR as a monitor of the aerial movement of the larger species, from which the migration of rice pests in general might be inferred.