Search Results

The presentation provides an overview about the activities of Eurocae Working Group 72 (WG-72) starting with a brief synopsis of the context which suggested why such a committee should be established in 2006. It then goes into further detail about the drivers for the work of the committee, which call for the products to be delivered. It addresses some of the challenges with respect to its users. It points out that one of the lessons the committee learned was importance of the focus on the users, such that the products provide their maximum utility. Hence, the users should better be among the participants to achieve this objective. Other industries have dealt with the subject of Information System (or Cyber-Physical) Security long before this industry was forced to consider it. Consequently there are many industry standards and national or international norms, which may help to develop what is deemed needed for Civil Aviation.

“Spotlight on Design: Insight” features an in-depth look at the latest technology breakthroughs impacting mobility. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. As global concerns about the negative consequences of greenhouse gases on the environment increase, regulatory agencies around the world are taking serious steps to address the issue of tailpipe emissions In the episode “Fuel Efficiency: Fuel Economy Testing” (12:05), engineers at the EPA’s National Vehicle and Fuel Emissions Laboratory demonstrate how different vehicles are tested for emissions, and AVL’s technical team shows how accurate tailpipe emissions can be measured and reported.

Simulation-based tolerance analysis is the accepted standard for dimensional engineering in aerospace today. Sophisticated 3D model-based tolerance analysis processes enable engineers to measure variation in complex, often large, assembled products quickly and accurately. Best-in-class manufacturers have adopted Quality Intelligence Management tools for collecting and consolidating this measurement data. Their goal is to completely understand dimensional fit characteristics and quality status before commencing the build process. This results in shorter launch cycles, improved process capabilities, reduced scrap and less production downtime. This paper describes how to use simulation-based approaches to correlate the theoretical tolerance analysis results produced during engineering simulations to actual as-built results. This allows engineers to validate or adjust as-designed simulation parameters to more closely align to production process capabilities.

Abstract It is reasonable to use a two-phase heat transfer loop (TPL) in a thermal control system (TCS) of spacecraft with large heat dissipation. One of the key elements of TPL is a heat-controlled accumulator (HCA). The HCA represents a volume which is filled with vapor and liquid of a single working fluid without bellows. The pressure in a HCA is controlled by the heater. The heat and mass transfer processes in the HCA can proceed with a significant nonequilibrium. This has implications on the regulation of TPL. This article presents a mathematical model of nonequilibrium heat and mass transfer processes in an HCA for microgravity conditions. The model uses the equations of mass and energy conservation separately for the vapor and liquid phases. Interfacial heat and mass transfer is also taken into account. It proposes to use the convective component k for the level of nonequilibrium evaluation.

This document contains guidance for designers, specifiers, regulatory personnel, purchasers, managers, and others who specify or use optical simulations of aircraft lights. All aircraft lighting will be considered interior, flight deck, and exterior lighting. Guidance on standard methods of analysis and presentation of data will be provided. Although this document concentrates on lighting, many of the principles covered will be helpful in other types of optical simulation, such as for displays, non-visible radiation, etc.

This SAE Aerospace Standard describes the system used by passenger boarding stairs (PBS) mobile passenger boarding ramps (PBS) and boarding bridges (PBB) to inform on-board cabin crew about the docking status of the PBS/PBR/PBB and whether it is positioned such that it is safe to open the aircraft door. Current practice calls for the PBS/PBR/PBB operator to knock on the aircraft door to inform the cabin crew that it is safe to open the aircraft door. New technologies being incorporated into PBS/PBR/PBB such as remote control systems and autonomous driving vehicles are entering the market. As such, new/updated controls and/or procedures are necessary to ensure continuing safe operations.

The purpose of this document is to establish the requirements for Real-Time Communication Protocols (RTCP). Systems for real-time applications are characterized by the presence of hard deadlines where failure to meet a deadline must be considered a system fault. These requirements have been driven predominantly, but not exclusively, by aerospace type military platforms and commercial aircraft, but are generally applicable to any distributed, real-time, control systems. These requirements are primarily targeted for the Transport and Network Layers of peer to peer protocols, as referenced in the Open System Interconnect Reference Model (2.2.1 and 2.2.2), developed by the International Standards Organization (ISO). These requirements are intended to complement SAE AS4074 (2.1.1) and AS4075 (2.1.2), and future SAE communications standards.

The purpose of this document is to establish the requirements for Real-Time Communication Protocols (RTCP). Systems for real-time applications are characterized by the presence of hard deadlines where failure to meet a deadline must be considered a system fault. These requirements have been driven predominantly, but not exclusively, by aerospace type military platforms and commercial aircraft, but are generally applicable to any distributed, real-time, control systems. These requirements are primarily targeted for the Transport and Network Layers of peer to peer protocols, as referenced in the Open System Interconnect Reference Model (2.2.1 and 2.2.2), developed by the International Standards Organization (ISO). These requirements are intended to complement SAE AS4074 (2.1.1) and AS4075 (2.1.2), and future SAE communications standards.

This Aerospace Standard (AS) provides a means for establishing a uniform method for specifying ultrasonic transducer performance, standardizing the measurement of transducer performance, and controlling allowable tolerances of transducer performance for the level specified on a purchase order or in a procurement specification. This standard identifies and defines transducer performance parameters and the method for measuring each parameter.

This Standard is intended to serve as a guide in the coordination of system design to promote uniformity of the nomenclature and description of the operator devices.

This standard applies to the interconnection of data terminal equipment and numerical control equipment at the tape reader interface. The data terminal would typically be connected to a remote data source/sink such as a computer. This standard defines: This standard is applicable for the interchange of signals when used in conjunction with electronic equipment, each interchange circuit of which has a single return (signal ground) that can be interconnected at the interface point. Figure 1.1, typical installation, shows how this standard should be applied to a typical tape reader interface of numerical control equipment.

This guide provides implementation consideration guidance for the normative clauses of IEEE/EIA 12207.0. The guidance is based on software industry experience with the life cycle processes presented in IEEE/EIA 12207.0.

Herschel and Planck satellites have recently undergone the thermal vacuum and thermal balance (TVTB) test which was performed in the ESA-ESTEC Large Space Simulator for Herschel and in Centre Spatial de Liège (CSL) for Planck. One of the specific targets of the Herschel test was the verification of the thermal stability of two HIFI units (required to be better than 3.10−4 °C/s) and of the Star Tracker mounting plate (required to be better than 2.5.10−3 °C/s), with particular attention on the performance of the relevant feedback control loops. Control system design and model predictions are presented and compared against the test results. Further discussion on the requirement verification is provided.

The Soft X-Ray Telescope (SXT) is an instrument on the International X-Ray Observatory (IXO). Its flight mirror assembly (FMA) has a single mirror configuration that includes a 3.3 m diameter and 0.93 m tall mirror assembly. It consists of 24 outer modules, 24 middle modules and 12 inner modules. Each module includes more than 200 mirror segments. There are a total of nearly 14, 000 mirror segments. The operating temperature requirement of the SXT FMA is 20°C. The spatial temperature gradient requirement between the FMA modules is ±1°C or smaller. The spatial temperature gradient requirement within a module is ±0.5°C. This paper presents thermal design considerations to meet these stringent thermal requirements.

Humidity control within confined spaces is of great importance for current NASA environmental control systems and future exploration applications. The engineered multifunction surfaces (MFS) developed by ORBITEC is a technology that produces hydrophilic and antimicrobial surface properties on a variety of substrate materials. These properties combined with capillary geometry create the basis for a passive condensing heat exchanger (CHX) for applications in reduced gravity environments, eliminating the need for mechanical separators and particulate-based coatings. The technology may also be used to produce hydrophilic and biocidal surface properties on a range of materials for a variety of applications where bacteria and biofilms proliferate, and surface wetting is beneficial.

An aircraft environmental control system (ECS) is commonly designed for a cabin that has been divided into several thermal control zones; each zone has an air flow network that pulls cabin air over an isolated thermocouple. This single point measurement is used by the ECS to control the air temperature and hence the thermal environment for each zone. The thermal environment of a confined space subjected to asymmetric thermal loads can be more fully characterized, and subsequently better controlled, by determining its “equivalent temperature.” This paper describes methodology for measuring and controlling cabin equivalent temperature. The merits of controlling a cabin thermal zone based on its equivalent temperature are demonstrated by comparing thermal comfort, as predicted by a “virtual thermal manikin,” for both air-temperature and equivalent-temperature control strategies.

In several industrial fields, the integration of functions is a key technology to enhance the efficiency of components in terms of performance to mass/volume/cost ratio. Concerning the space industry, in the last few years the trend in spacecraft design has been towards smaller, light-weight and higher performance satellites with sophisticated payloads and instrumentation. Increasing power density figures are the common feature of such systems, constituting a challenging task for the Thermal Control System. The traditional mechanical and thermal design concepts are evidencing their limits with reference to such an emerging scenario.

Direct injection spark-ignition (DISI) gasoline engines can offer better fuel economy and higher performance over their port fuel-injected counterparts, and are now appearing increasingly in more U.S. vehicles. Small displacement, turbocharged DISI engines are likely to be used in lieu of large displacement engines, particularly in light-duty trucks and sport utility vehicles, to meet fuel economy standards for 2016. In addition to changes in gasoline engine technology, fuel composition may increase in ethanol content beyond the 10% allowed by current law due to the Renewable Fuels Standard passed as part of the 2007 Energy Independence and Security Act (EISA). In this study, we present the results of an emissions analysis of a U.S.-legal stoichiometric, turbocharged DISI vehicle, operating on ethanol blends, with an emphasis on detailed particulate matter (PM) characterization.