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Research Report

Unsettled Issues Concerning Integrated Vehicle Health Management Systems and Maintenance Credits

2020-05-27
EPR2020006
The “holy grail” for prognostics and health management (PHM) professionals in the aviation sector is to have integrated vehicle health management (IVHM) systems incorporated into standard aircraft maintenance policies. Such a change from current aerospace industry practices would lend credibility to this field by validating its claims of reducing repair and maintenance costs and, hence, the overall cost of ownership of the asset. Ultimately, more widespread use of advanced PHM techniques will have a positive impact on safety and, for some cases, might even allow aircraft designers to reduce the weight of components because the uncertainty associated with estimating their predicted useful life can be reduced. We will discuss how standard maintenance procedures are developed, who the various stakeholders are, and – based on this understanding - outline how new PHM systems can gain the required approval to be included in these standard practices.
Magazine

Tech Briefs: September 2018

2018-09-01
Enhanced SATCOMs for Unmanned Aerial Systems The Bus Too Tough to Die Combating Infrared Threats on the Battlefield Optical Interconnect Design Challenges in Space High-Performance Computing for the Next-Generation Combat Vehicle Merging Antenna and Electronics Boosts Energy and Spectrum Efficiency Integrated Magneto-Optical Devices for On-Chip Photonic Systems Development of magneto-optical (MO) materials could lead to a range of nonreciprocal optical devices for emerging standardized photonic integrated circuit (PIC) fabrication processes. Low Power Optical Phase Array Using Graphene on Silicon Photonics Electrostatic doping of 2D materials embedded in waveguides could enable ultrafast devices with unprecedented power. Spatial Resolution and Contrast of a Focused Diffractive Plenoptic Camera New technology captures spectral and spatial information of a scene in one snapshot while raising pixel counts and improving image quality.
Magazine

Tech Briefs: June 2018

2018-06-01
Beyond VMEbus - A New Concept Taming the Thermal Behavior of Solid-State Military Lasers Solving the Challenge of Thermal Design in Aerospace Electronics Improving Component Life in Abrasive, Corrosive Aerospace Environments New Pulse Analysis Techniques for Radar and EW Validation of Ubiquitous 2D Radar Converting Existing Copper Wire Firing System to a Fiber-Optically Controlled Firing System for Electromagnetic Pulsed Power Experiments Technological improvements make pulsed-power experiments with gunpowder- or air-driven guns safer. Low-Cost Ground Sensor Network for Intrusion Detection COTS-based system could provide increased level of security with less manpower. In-Network Processing on Low-Cost IoT Nodes for Maritime Surveillance Commercially available system of distributed wireless sensors could increase the Navy's intelligence collection footprint.
Journal Article

TOC

2024-02-12
Abstract TOC
Technical Paper

System Concept Effectiveness

1966-02-01
660728
Frequently, a choice between system concepts must be made on the basis of something other than a detailed evaluation of the design effectiveness of these systems. This paper develops a rudimentary analysis process for use in addressing this problem.
Article

SAE International extends call for abstracts, seeks submissions for AeroTech conference

2022-08-11
Engineering Events staff at SAE International in Warrendale, Pennsylvania, have extended the call for abstracts through September 21 for the organization’s AeroTech aerospace and defense technology conference, which will take place at the Fort Worth Convention Center in Fort Worth, Texas, March 14-16, 2023. Visit the AeroTech call for abstracts page for more information and to get started.
Research Report

Process Control for Defect Mitigation in Laser Powder Bed Fusion Additive Manufacturing

2023-05-15
EPR2023011
Success in metal additive manufacturing (AM) relies on the optimization of a large set of process parameters to achieve materials whose properties and performance meet design and safety requirements. Despite continuous improvements in the process over the years, the quality of AM parts remains a major concern for manufacturers. Today, researchers are starting to move from discrete geometry-dependent build parameters to continuously variable or dynamically changing parameters that are geometry- and scan-path aware. This approach has become known as “feedforward control.” Process Control for Defect Mitigation in Laser Powder Bed Fusion Additive Manufacturing discusses the origins of feedforward control, its early implementations in AM, the current state of the art, and a path forward to its broader adoption. Click here to access the full SAE EDGETM Research Report portfolio.
Journal Article

Predictive Modeling of Aircraft Dynamics Using Neural Networks

2022-05-25
Abstract Fighter pilots must study models of aircraft dynamics before learning complex maneuvers and tactics. Similarly, autonomous fighter aircraft applications may benefit from a model-based learning approach. Instead of using a preexisting physics model of a given aircraft, a machine learning system can learn a predictive model of the aircraft physics from training data. Furthermore, it can model interactions between multiple friendly aircraft, enemy aircraft, and the environment. Such a system can also learn to represent state variables that are not directly observable, as well as dynamics that are not hard coded. Existing model-based methods use a deep neural network that takes observable state information and agent actions as input and provides predictions of future observations as output. The proposed method builds upon this approach by adding a residual feedforward skip connection from some of the inputs to all of the outputs of the deep neural network.
Standard

Perspectives on Integrating Structural Health Monitoring Systems into Fixed-Wing Military Aircraft

2019-09-18
CURRENT
AIR6245
This SAE Aerospace Information Report (AIR) is prepared for stakeholders seeking information about the evolution, integration, and approval of SHM technologies for military aircraft systems. The report provides this information in the form of (a) two military organizations’ perspectives on requirements, and (b) general SHM challenges and industry perspectives. The report only provides information to generate awarness of prespectives for military aircraft and, hence, assists those who are involved in developing SHM systems understanding the broad range of regulations, requirements, and standards published by military organizations that are available in the public domain from the military organizations.
Standard

NATIONAL AEROSPACE AND DEFENSE CONTRACTORS ACCREDITATION PROGRAM REQUIREMENTS FOR NONCONVENTIONAL MACHINING

2002-02-01
HISTORICAL
AS7116
This Aerospace Standard (AS) establishes the requirements for suppliers of Nonconventional Machining Services to be accredited by the National Aerospace and Defense Contractors Accreditation Program (NADCAP). NADCAP accreditation is granted in accordance with SAE AS7003 after demonstration of compliance with the requirements herein. The requirements may be supplemented by additional requirements specified by the NADCAP Nonconventional Machining and Surface Enhancement (NMSE) Task Group. Using the corresponding Audit Criteria (PRI AC7116) will ensure that accredited Nonconventional Machining suppliers meet all of the requirements in this standard and all applicable supplementary standards. The purpose of this audit program is to assess a supplier's ability to consistently provide a product or service that conforms to the technical specifications and customer requirements.
Technical Paper

Methodology and Results of Testing an Impact of F-34 Fuel on the Engine Reliability

2020-09-15
2020-01-2133
An application of the new kind of the fuel for the diesel engine requires to conduct the qualification tests of the engines powered by this his fuel which allow assessing an impact of fuel on the engine reliability. Such a qualification test of the piston and turbine engines of the aircraft stationed on the ground and land vehicles is described in the NATO standardisation agreement (STANAG) 4195 as the AEP-5 test. The methodology and selected results of the qualification tests of the SW-680 turbocharged multi-purpose diesel engine fuelled with F-34 fuel have been presented in this paper. A dynamometric stand with the SW-680 engine has been described. Based on the preliminary results of the investigation it has been found that a change in a type of the fuel from IZ-40 diesel fuel into F-34 kerosene-type one has reduced a maximum engine torque by about 4%. This has been primarily due to a lower fuel density of F-34 by about 3%.
Journal Article

Infrared Signature of Fixed and Variable Area C-D Nozzle of Aircraft Engine

2023-01-02
Abstract The use of converging-diverging (C-D) variable area nozzle (VAN) in military aeroengines is now common, as it can give optimal expansion and control over engine back pressure, for a wide range of engine operations. At higher main combustion temperatures (desired for supercruise), an increase in the nozzle expansion ratio is needed for optimum performance. But changes in the nozzle throat and exit areas affect the visibility of engine hot parts as the diverging section of the nozzle is visible for a full range of view angle from the rear aspect. The solid angle subtended by engine hot parts varies with change in visibility, which affects the aircraft infrared (IR) signature from the rear aspect. This study compares the performances of fixed and variable area nozzles (FAN and VAN) in terms of engine thrust and IR signature of the engine exhaust system in the boresight for the same increase in combustion temperature.
Standard

IEEE-1394b for Military and Aerospace Vehicles - Applications Handbook

2019-08-12
CURRENT
AIR5654A
This Handbook is intended to accompany or incorporate AS5643, AS5643/1, AS5657, AS5706, and ARD5708. In addition, full understanding of this Handbook also requires knowledge of IEEE-1394-1995, IEEE-1394a, and IEEE-1394b standards. This Handbook contains detailed explanations and architecture analysis on AS5643, bus timing and scheduling considerations, system redundancy design considerations, suggestions on AS5643-based system configurations, cable selection guidance, and lessons learned on failure modes.
Book

Hall-Scott: The Untold Story of a Great American Engine Maker

2007-01-25
Author Francis Bradford, a former Hall-Scott engineer, provides valuable resources and insight not available to any other Hall-Scott researcher. Well-illustrated with numerous photos, drawings, and memos, this fascinating book will be of interest to history buffs in the areas of aviation, rail, marine, trucks, buses, fire equipment, and industrial engines, and to World War and military historians.
Technical Paper

Guiding Framework for Feasibility Evaluation of Localised Production and Drop in Blending of Aviation Turbine Fuel with Bio Derivatives for Non-civilian Air Bases

2011-10-18
2011-01-2792
The potential for small scale local production of Bio fuel derivatives and their partial blending with aviation turbine fuel in non-civilian bases has been investigated. A feasibility study on technical readiness levels for process viability is presented in the paper. Demand side analysis for various blend mixes and corresponding requirement for production facilities and land area requirements are performed. Sustainable production and blending operations are the basis for selection of key performance indicators for the air base. Guiding framework and readiness evaluation processes are delineated for the base. Qualitative inference is combined with quantitative scoring system within the framework.
Technical Paper

Future Military APU Requirements

1991-09-01
912176
Future tactical aircraft will have increased capabilities that will place greater demands on their secondary power systems. Added capabilities such as low observability or internal weapons storage are being planned for without significantly increasing the aircraft's size and weight. The power system must therefore have reduced volume, weight, and complexity, while also being more reliable and maintainable. The auxiliary power unit (APU) is a critical component that must be improved to upgrade the capabilities of the power system. Increasing the APU's power density is one important way for reducing the power system's size and weight. Increased power density, however, will require a power unit operating with higher gas generator temperatures, so this condition will be the major challenge for new APU designs.
Journal Article

Framework for Initializing the Conceptual Design of Hypersonic Aircraft

2023-01-18
Abstract To assist in initializing the conceptual design of hypersonic aircraft, we outline a new, systematic framework based on historical aircraft data and primarily composed of design data and regression models. It is a rapid, low-fidelity analysis to provide a starting point for the conceptual design process by (1) assessing the performance capabilities of four types of high-speed aircraft, (2) providing initial estimates for weights and geometry with uncertainty, and (3) exploring how changes in these affect performance within design spaces. Using this framework, an initial set of reasonable aircraft configurations is obtained based on speed, altitude, and payload requirements, which can serve to accelerate the design process and avoid unforeseen problems later in the design cycle. An example is provided to demonstrate the application of the framework to launch the conceptual design of a new hypersonic aircraft with a given set of mission requirements.
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