Refine Your Search




Search Results


Gas Nitriding of Low-Alloy Steel Parts

This document specifies the procedure and requirements for gas nitriding low-alloy and tool steels by the use of raw or dissociated ammonia. Additional alloys and steel families (e.g., stainless steels) can also be nitrided using parameters acceptable to the cognizant engineering organization.

Pyrometer for Nonmetallic Processing

This specification, in conjunction with AMS2750, covers pyrometric requirements for equipment used for the thermal processing of nonmetallic products. Specifically, it covers temperature sensors, instrumentation, thermal processing equipment, correction factors and instrument offsets, system accuracy tests, and temperature uniformity surveys. These are necessary to ensure that products are cured or formed in accordance with the applicable specification(s). This specification also covers pressure or vacuum requirements for thermal processing equipment.

Lighting for Camera Video Systems

The scope of this ARP is area lighting requirements for commercial airplane camera video systems. Specifically, lighting recommendations are given for the GMCS (ground maneuver camera system) and FDEVSS (flight deck entry video surveillance system). This ARP affects all three A-20 Aircraft Lighting Committees: crew station flight deck, exterior, and interior. Future updates could include military applications.

Assessment of Evaluation Method Types to Determine Energy Efficiency of Multi-Vehicle Systems

This document provides an assessment of current engineering test and simulation standards and methods used to determine the fuel efficiency, freight efficiency and emissions of single-vehicle systems comprised primarily of on-road trucks and buses with GVWR of more than 10000 pounds (4535 kg). This document provides guidance on the applicability and use of each test and simulation standard, method and technology discussed for multi-vehicle systems.
Technical Paper

Integrating Body-In-White Influences on Vehicle Dynamics into Real-Time Models

Elastokinematic parameters of the axle stiffness are one of the important effects for vehicle dynamics, which are usually considered in full-vehicle real-time models. In order to integrate such effects into real-time models, a multibody axle model is placed on the suspension test rig and is clamped at mounting points. Statically defined load cases are applied on the wheel, and finally, lookup tables are generated, which represent the elastokinematics for the real-time environment. In this case, the Body-In-White (BIW) is considered to be ideally stiff. However, the elasticity of BIW significantly influences the elastokinematics behavior as well and should be integrated into real-time models. The present paper introduces an efficient approach to integrate the BIW compliance effects into lookup tables in addition to the suspension stiffness under consideration of the Elastokinematics By Inertia Force method (EBIF method).
Journal Article

Synthesis of a Vehicle Suspension with Constrained Lateral Space using a Roll-plane Kineto-dynamic Model

The larger chassis space requirements of hybrid vehicles necessitates considerations of the suspension synthesis with limited lateral space, which may involve complex compromises among performance measures related to vehicle ride and handling. This study investigates the influences of suspension linkage geometry on the kinematic and dynamic responses of the vehicle including the wheel load in order to facilitate synthesis of suspension with constrained lateral space. A kineto-dynamic half-car model is formulated incorporating double wishbone suspensions with tire compliance, although the results are limited to kinematic responses alone. An optimal synthesis of the suspension is presented to attain a compromise among the different kinematic performance measures with considerations of lateral space constraints. In the kineto-dynamic model, the struts comprising linear springs and viscous dampers are introduced as force elements.
Journal Article

Energy Finite Element Analysis Developments for Vibration Analysis of Composite Aircraft Structures

The Energy Finite Element Analysis (EFEA) has been utilized successfully for modeling complex structural-acoustic systems with isotropic structural material properties. In this paper, a formulation for modeling structures made out of composite materials is presented. An approach based on spectral finite element analysis is utilized first for developing the equivalent material properties for the composite material. These equivalent properties are employed in the EFEA governing differential equations for representing the composite materials and deriving the element level matrices. The power transmission characteristics at connections between members made out of non-isotropic composite material are considered for deriving suitable power transmission coefficients at junctions of interconnected members. These coefficients are utilized for computing the joint matrix that is needed to assemble the global system of EFEA equations.
Journal Article

Energetic Design and Optimization of a Large Photovoltaic Stratospheric Unconventional Feeder Airship

This paper presents a model of energetic consumption and photovoltaic production for a large airship which acts as feeder connecting the ground with a large cruiser. The analysis of energy needs and productivity allows defining both an ideal sizing and operative mission profiles. The specialised mission of this airship is to ascent and descent. It includes also the connection with the airport buildings on the ground and with the cruiser at high altitude. Photovoltaic production has evaluated in terms of hydrogen and electric propulsion. They have estimated both and a calculation methodology has proposed. The evaluation has supported by CFD evaluations on aerodynamic behaviour of the system at various altitudes.
Journal Article

Composite AC-to-DC Power Converters for More Electric Architectures

This paper presents a novel method and system for an electric power alternating-current (AC)-to-direct-current (DC) converter employing composite technology. The term composite entails utilization of more than one type of conversion operating in parallel. In addition, background information for the prior art, based on conventional autotransformer rectifier units (ATRUs), and active converters are discussed. The major requirements of AC-to-DC converters from both functional and protection perspectives are provided. The concept of the new approach is defined. Comparative analysis between the new and old methods is documented. The performance features and technical details of the system parameters with respect to AC-to-DC converter system requirements are presented and discussed. Analysis, simulation results, and test data are included. Finally, the advantages of this technology, which nearly doubles power density compared to the state-of-the-art, are summarized and a conclusion included.

Assessment of Electric Engine Failures Leading to LOPC

This Aerospace Information Report provides guidance to assess the tolerance of an aircraft electric engine design to electrical and electronic failures leading to Loss of Power Control (LOPC) or Loss of Thrust Control (LOTC) events. Its intent is to provide a means to demonstrate compliance to certification requirements. At issue 1, this document only addresses fully electric engine configurations targeting single engine aircraft applications with conventional engine installation. It may also be suitable for multi-engine general aviation applications with conventional engine installation.
Journal Article

A New Catalyzed HC Trap Technology that Enhances the Conversion of Gasoline Fuel Cold-Start Emissions

Passive in-line catalyzed hydrocarbon (HC) traps have been used by some manufacturers in the automotive industry to reduce regulated tailpipe (TP) emissions of non-methane organic gas (NMOG) during engine cold-start conditions. However, most NMOG molecules produced during gasoline combustion are only weakly adsorbed via physisorption onto the zeolites typically used in a HC trap. As a consequence, NMOG desorption occurs at low temperatures resulting in the use of very high platinum group metal (PGM) loadings in an effort to combust NMOG before it escapes from a HC trap. In the current study, a 2.0 L direct-injection (DI) Ford Focus running on gasoline fuel was evaluated with full useful life aftertreatment where the underbody converter was either a three-way catalyst (TWC) or a HC trap. A new HC trap technology developed by Ford and Umicore demonstrated reduced TP NMOG emissions of 50% over the TWC-only system without any increase in oxides of oxygen (NOx) emissions.

Powder Coating Application

This specification provides the minimum requirements for the application of AMS3143 powder coatings to aerospace components.