涡轮平面叶栅非轴对称端壁优化设计

开发了一套造型灵活直观、网格生成速度快的涡轮平面叶栅非轴对称端壁优化设计工具,该工具的核心技术是非均匀有理B样条(NURBS)曲面造型和网格变形.在此基础上以商业软件Isight为优化驱动器,以CFX为求解器,搭建了非轴对称端壁优化设计流程.以Pack B涡轮平面叶栅为例,对其进行了非轴对称端壁优化设计.优化后涡轮平面叶栅总压损失系数减小了12.96%.结果表明:涡轮平面叶栅端部的静压分布改变削弱了涡轮平面叶栅通道中马蹄涡、通道涡的强度,提高了涡轮平面叶栅的气动性能.      

旅客机环境控制系统的发展

回顾了飞机环境控制系统在民用旅客机应用中的技术发展过程,介绍了现役各种民用飞机的不同技术方案的环境控制系统特点,比较讨论了３种不同中型民用旅客机的环境控制系统方案,展望了民用飞机的环境控制系统的发展趋势。     

热等静压法制备B/Al复合型材的研究

介绍了热等静压法制Ｂ／Ａｌ复合型材的工艺过程,对热等静压法制备Ｂ／Ａｌ复合型材的工艺进行了探索研究,获得了制备Ｂ／Ａｌ复合型材,可一次成型多根质量符合要求的常用形式的Ｂ／Ａｌ复合型材。     

A new deterministic VXI highway interconnect

Programs based upon the VXIbus modular instrumentation standard are playing a significant role in test systems for both defense and commercial applications. Typical single-chassis VXI systems include an embedded computer-based controller as the system host. Multi-chassis systems generally use a parallel bus or a local area network, such as Ethernet, to interconnect the chassis. An important class of multi-chassis test systems requires high I/O throughput, low latency and a highly deterministic I/O response. This paper describes a new highway interconnect system that includes host computer interface options for VMEbus, EISA and PCI bus. A typical system is configured with a host interface, a fiber-optic highway “loop” and slot-0 controllers in the VXI chassis. The system supports up to 126 VXI chassis, an aggregate I/O throughput of 10 megabytes per second, extremely low latency and a highly deterministic I/O response. Typical applications, including jet aircraft engine testing, missile test systems and high-performance wind tunnel data systems are discussed     

Achieving higher levels of electronic integration throughsystem-on-chip

All aerospace vehicles have the common constraint of limited space for the electronic systems. The challenge has always been how to pack effective electronic systems into the space available. Higher levels of electronic integration can give a competitive advantage; for example, by providing extra channels in a communications satellite thereby increasing revenue to the operator. Today's deep sub-micron manufacturing processes for integrated electronics offer an opportunity for a step change for electronic functionality that can be packaged in a given space. This technology makes possible, for the first time, a true system-on-chip approach to electronic systems, which is already being exploited by the commercial sector in products such as the mobile telephone     

Space Weather and the Ground-Level Solar Proton Events of the 23rd Solar Cycle

Solar proton events can adversely affect space and ground-based systems. Ground-level events are a subset of solar proton events that have a harder spectrum than average solar proton events and are detectable on Earth’s surface by cosmic radiation ionization chambers, muon detectors, and neutron monitors. This paper summarizes the space weather effects associated with ground-level solar proton events during the 23rd solar cycle. These effects include communication and navigation systems, spacecraft electronics and operations, space power systems, manned space missions, and commercial aircraft operations. The major effect of ground-level events that affect manned spacecraft operations is increased radiation exposure. The primary effect on commercial aircraft operations is the loss of high frequency communication and, at extreme polar latitudes, an increase in the radiation exposure above that experienced from the background galactic cosmic radiation. Calculations of the maximum potential aircraft polar route exposure for each ground-level event of the 23rd solar cycle are presented. The space weather effects in October and November 2003 are highlighted together with on-going efforts to utilize cosmic ray neutron monitors to predict high energy solar proton events, thus providing an alert so that system operators can possibly make adjustments to vulnerable spacecraft operations and polar aircraft routes.     

High Power Needs for Commercial Satellites

This overview paper presents estimates of the photovoltaic power systems needed on commercial communications spacecraft in the year 2000. These are developed in the form of power requirements based on extrapolation of the historical growth in communications traffic and are about 5 to 15 kW. The paper also addresses the key technology drivers in these photovoltaic systems. The importance of reducing mass in the power system is described in terms of the tradeoff with communications systems mass to maximize communications revenue. It surveys solar array components and subsystems to meet these future requirements and attempts to identify the development candidates with a large payoff potential and a high probability of successful development.     

飞行管理计算机系统双计算机主从结构的运行

本文先叙述了飞行管理计算机系统在我国目前民航飞机上的配备情况,说明了系统在飞机上的余度配置。装有两套飞行管理计算机系统的飞机上,为了协调工作,要区分为“主”和“从”系统。分析了“主”“从”系统在工作中的区别以及如何确定“主”或“从”系统的布局,最后说明在工作中如何进行故障检测,一旦某台设备失效,如何使系统重组以恢复正常工作。     

测控中心计算机系统的自主可控技术研究

测控中心计算机系统是测控中心的核心枢纽,通过自主可控技术加强其安全性,摆脱对国外软硬件的依赖,是当务之急。在分析测控中心计算机系统特点的基础上,对测控中心计算机系统自主可控技术的研究与实践进行了总结,列举了实践中遇到的基础部件国产化程度不高、开源软件问题多、自主可控产品商品化程度不高等问题。针对自主可控技术不甚成熟的情况,提出了国产软硬件产品的技术摸底、详尽测试、加强基础软件的版本管理和控制等发展建议,以推动自主可控技术在测控中心领域的应用和发展。     

Commilitary-another new world order

The use of commercial practices to achieve military functional designs that provide high performance in inexpensive systems, designated here commilitary, is examined. Commilitary designs call for a mix of military quality and technology with some basic restrictions and approaches that are common to the commercial world. Areas such as parts selection, environmental conditions, levels of inspection and test, and configuration control which must be tailored for high volume modules are explored. A forward looking predictive windsheer radar is presented as a successful application of this approach     

Space power-whats old is new again

The nation is presently seeking smaller and faster space missions that cost less. Furthermore, there is pressure to spin off technologies into the commercial sector as well as spin in technologies to the space program. In this environment, ideas that were dismissed in the past have come to the forefront again. This paper discusses high performance photovoltaic devices, solar dynamic systems, new batteries and power management and distribution schemes. Spin offs of power technologies are impacting aeronautical, terrestrial and naval applications as well. It is believed that interactions with terrestrial commercial industries will lead to deeper understanding of how to reduce space costs as well as increasing quality and reliability     

Airborne hyperspectral sensor systems

This paper presents brief profiles of 19 airborne hyperspectral sensor systems currently or nearly available for data acquisition. These systems represent various design concepts and innovations in hyperspectral information collection technology. A number of companies now have the ability to acquire data from these systems. As the scientific and commercial communities become aware of hyperspectral imaging data acquisition opportunities, more applications for this type of data will be investigated and implemented     

Integrated electro-hydraulic system modeling and analysis

The technical approach for the development of the computer model of an integrated electro-hydraulic system is presented. As an example, the development of the computer model of the Space Shuttle Electric Auxiliary Power Unit (EAPU) is discussed. The integrated model consists of power source, electric power distribution and control (EPD&C), and mechanical and hydraulic loads. The modeling and analysis results, model interface issues, EPD&C interactions with the power sources, and EPD&C interaction with the electro-hydraulic load are discussed . The selected computer tool facilitates the development of "submodel" corresponding to the subsystem in the integrated system. This modeling approach and the models developed for EAPU can be generalized and adapted for the detailed modeling, simulation, and analysis of other aerospace and commercial electro-mechanical systems     

Power anomaly effects and costs in low-voltage mobile power systems

Electric power anomalies or disturbances can disrupt the normal operation of equipment, accelerate aging, or even cause outright failures thus resulting in increased costs of maintenance and reduced system reliability. Past research on the effects caused by power anomalies has been mostly focused on industrial, commercial, or residential systems, or on power distribution equipment. A literature survey reveals that there is no comprehensive review related to low-voltage (LV) power systems and utilization equipment applicable to military combat vehicles, such as aircraft and ships. This paper summarizes the results of a new literature survey that focused on the causes, effects, and mitigation methods for power anomalies typical of LV mobile power systems. Electric power anomaly cost data collected from the literature are also presented, from which the costs of anomalies to the national defense are estimated using some simple rationales.     

A fault-tolerant air data/inertial reference unit

The fault-tolerant air data/inertial reference unit (ADIRU) described is a key part of a fault-tolerant air data/inertial reference system (ADIRS) designed to be the inertial and air data reference for the ARINC 651 Integrated Modular Avionics (IMA) distributed architecture. The ADIRU has been designed to meet the commercial aviation market demands for low life cycle cost and high integrity fault detection, fault isolation, and redundancy management. The ADIRU's internal redundant resources provide quad channel redundancy that is one level higher than conventional triple redundant systems, allowing it to provide deferred maintenance capability. Robust partitioning, simple serial internal interfaces, and simple voting planes ensure that internal redundant components are properly utilized to provide high integrity system outputs. This relieves systems using it from having to perform their own redundancy management of the air data and inertial outputs from multiple sources required by conventional systems     

薄壁异形树脂基复合材料近净尺寸成型研究

通过对成型工艺选择、模具结构设计及工艺参数的研究,探索了薄壁异形树脂基复合材料近净尺寸成型。研究结果表明,注料式模压克服了传统模压成型装料腔狭窄不易装料的问题,实现了薄壁异形树脂基复合材料的近净尺寸成型,极大地提高了材料利用率、降低了加工难度、缩短了成型周期。     

The future of military standards. A focus on electronics

The growing perception that with cutbacks in the military and the changing international economic environment, the military must rely on commercial industries in order to afford the next generation of high-performance and high-reliability military systems is discussed. One issue associated with the question of whether an industrial base for the military can be provided and maintained without major changes in the operation of both the government and commercial industry is examined, namely, whether commercial standards can effectively supplant military standards and still provide high performance and reliability for military missions     

Robotic technology integration for army ground vehicles

This paper discusses the US Army Tank Automotive Research, Development and Engineering Center's (TARDEC's) four (4) axis strategy for integration of robotics into the legacy, interim, and objective forces. At the cornerstone of this strategy is the R&D effort concentrating on autonomous perception and navigation, intelligent tactical behavior, command and control, and man-robot interface entailed in the Demo III and Robotic Follower programs. Smart Manned Systems focuses on a systems engineering approach for robotic solutions into the interim force (Vetronics Technology Testbed and Crew Integration & Automation Testbed). In the near-term, application of robotics to the legacy force will be achieved through adapting commercial automation technologies, which address military requirements. Finally, Intelligent Mobility will investigate improving intrinsic platform mobility to lessen the burden on robotic sensing performance. The ultimate goal of this strategy is to advance the robotics technology state-of-the-art to achieve off-road full autonomous operations for military systems in support of the objective force