Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Using a Specific Environmental Tool to Assess the Impacts of Biofuels Transport Policies

2013-09-17
2013-01-2167
Over the past few years the aviation industry has worked hard on how to replace fossil fuels by biofuels that would meet specific aviation criteria. But before implementing expensive biojet fuel manufacturing it seems legitimate to study global environmental impacts of a significant share of biofuels in transports by 2020. For that purpose, a method has been developed to study biofuels policies based on the life cycle methodology and adapted to the macro level to study indirect large scale effects on economic sectors. In this study, an economic general equilibrium model, has been coupled with an environmental Input/Output table in order to provide the amount of substances emitted in the environment by each economic sector in each region of the world when a biofuel policy is implemented. The economic model is also able to provide data for land use change that are then coupled with environmental factors, to obtain greenhouse gas emissions.
Technical Paper

Using Neural Networks to Compensate Altitude Effects on the Air Flow Rate in Variable Valve Timing Engines

2005-04-11
2005-01-0066
An accurate air flow rate model is critical for high-quality air-fuel ratio control in Spark-Ignition engines using a Three-Way-Catalyst. Emerging Variable Valve Timing technology complicates cylinder air charge estimation by increasing the number of independent variables. In our previous study (SAE 2004-01-3054), an Artificial Neural Network (ANN) has been used successfully to represent the air flow rate as a function of four independent variables: intake camshaft position, exhaust camshaft position, engine speed and intake manifold pressure. However, in more general terms the air flow rate also depends on ambient temperature and pressure, the latter being largely a function of altitude. With arbitrary cam phasing combinations, the ambient pressure effects in particular can be very complex. In this study, we propose using a separate neural network to compensate the effects of altitude on the air flow rate.
Technical Paper

Use of Vibration Signal for Diagnosis and Control of a Four-Cylinder Diesel Engine

2011-09-11
2011-24-0169
In order to meet the stricter and stricter emission regulations, cleaner combustion concepts for Diesel engines are being progressively introduced. These new combustion approaches often requires closed loop control systems with real time information about combustion quality. The most important parameter for the evaluation of combustion quality in internal combustion engines is the in-cylinder pressure, but its direct measurement is very expensive and involves an intrusive approach to the cylinder. Previous researches demonstrated the direct relationship existing between in-cylinder pressure and engine block vibration signal and several authors tried to reconstruct the pressure cycle on the basis of information coming from accelerometers mounted on engine block. This paper proposes a method, based on the analysis of the engine vibration signal, for the diagnosis of combustion process in a Diesel engine.
Technical Paper

Use of Portable Gas Analyzers in an Environment with High Background Hydrogen Levels

2004-07-19
2004-01-2338
The US Navy monitors atmospheric constituents aboard nuclear submarines with a ruggedized mass spectrometer called the Central Atmosphere Monitoring System (CAMS). The CAMS aboard each submarine is capable of sensing oxygen, nitrogen, carbon dioxide, carbon monoxide, water vapor and refrigerants in all regularly occupied spaces. This setup fulfills the majority of the Navy’s needs, however, the CAMS is not capable of “sniffing” enclosed spaces nor providing data after certain casualty situations. To meet these two critical needs and provide backup monitoring capability for the CAMS, the US Navy currently uses various gas-sensing colorimetric tubes. Aside from the traditional unpopularity of these tubes with the fleet, recent investigations have shown them to be inefficient, expensive and difficult to obtain. With that background, testing was funded to determine if the colorimetric tubes could be replaced with modern portable atmosphere monitoring equipment.
Standard

Use of HVOF Thermal Spray Coatings for Hard Chrome Replacement in Landing Gear Applications

2007-02-22
CURRENT
ARP5935
Electrolytically deposited chrome plate is the current standard surface treatment for landing gear component interface surfaces that require good wear resistance and corrosion protection. Chrome plated components are typically plagued by a slight debit in fatigue performance, detrimental mud cracking surface pattern, susceptibility to scoring, wear, and seal leakage. In addition, recent changes in environmental compliance standards place further restrictions on the use of electrolytically deposited chromium. Some commercial applications have already eliminated the use of chrome plate on current and future products. As a result, a substitute for electrolytically deposited chrome plate has been sought for several years. High Velocity Oxygenated Fuel (HVOF) thermal spray coatings have been developed to the point where they are being implemented as an alternative to hard chrome plate on high strength low alloy steels for external surfaces on landing gear applications.
Technical Paper

Use of Alternate Fuels in Light Aircraft

2002-04-16
2002-01-1539
Light aircraft are older, simpler technologies than modern cars, and thus easier to convert to utilize alternative liquid fuels. The specific differences between aircraft and automotive technologies impacts the choice of conversion approach. Fuels of technological interest include alcohols, ethers, and blends of these with gasolines or each other, but ethanol appears to be the preferred choice. Conversion must address metering, compatibility, timing, cold start, intake icing, and the delivery of increased fuel flow rates. Routine alternate fuels use implies that blends will be flown during the transition period from aviation gasoline to the new fuel. The two most important issues that must be addressed for safety of flight with gasoline-ethanol blends are moisture-induced phase separation and vapor lock behavior. Fuel density and handling characteristics appear not to be a problem.
Article

United ups commitment to sustainable aviation biofuel, extends contract with World Energy

2019-05-23
United Airlines officials in Chicago have strengthened their commitment to ensuring United is an environmentally conscious carrier by expanding its contract with Boston-based World Energy and agreeing to purchase up to 10 million gallons of commercial-scale, sustainable aviation biofuel over the next two years. United currently uses the biofuel to help sustainably power every flight departing out of its Los Angeles Airport (LAX) hub and achieve more than a 60 percent reduction in greenhouse gas emissions on a lifecycle basis, officials say.
Technical Paper

Unfurlable Space Based Heat Pipe Radiator

1996-07-01
961456
Current state-of-the-art space radiators are too heavy (5-7 kg/m2) and voluminous to be feasible for some future space missions. Accordingly, there is a need for a revolutionary advanced space radiator system. This paper describes an effort to satisfy that need through the development of an unfurlable heat pipe radiating system. The innovative portion of the unfurlable radiator is the pressure envelope: it is a thin, flexible, heat sealable polymer/metal laminate that is vacuum tight. The laminate allows the radiator to be compactly rolled or folded, easily stowed for transit to space and then unfurled to present a large radiating surface. Condensate return to the evaporator is achieved by a combination of capillary pumping via a flexible porous cable wick and the advanced capillary pumped loop methods of entrainment. The mass density of the radiator is 1.76 kg/m2, representing a reduction in mass of at least a factor of 3 over current radiator technology.
Journal Article

Ultra-Compact Power System for Long-Endurance Small Unmanned Aerial Systems

2012-10-22
2012-01-2177
Air-launched Small Unmanned Aerial Systems (SUASs) provide critical information to warfighters, but are currently limited by the power and energy available from small electric propulsion systems. This paper describes proof-of-concept testing of a novel power system for SUASs. The power system comprises a compact hydrogen generator and a hydrogen PEM fuel cell. The hydrogen generator uses ammonia borane (AB) as a solid chemical hydrogen storage material and heats the AB to produce hydrogen through thermal decomposition. The innovative ignition and control process generates highly pure hydrogen on-demand from a system that is very compact, lightweight, and rugged. We built a proof-of-concept hydrogen generator and used it to supply hydrogen to a small PEM fuel cell. The proof-of-concept generator used prototypical AB, heat source, control scheme, and purification media to absorb trace amounts of ammonia, borazine, and carbon monoxide (CO).
Technical Paper

TurboGenerator™ Power Systems for Electric Power Generation

1998-04-21
981278
The search for clean, compact, cost effective energy sources isn't new. In fact it is as old as humanity. Over the past decade AlliedSignal has focused its attention developing TurboGenerator™ Power Systems that can be used in industrial, automotive and aerospace applications, AlliedSignal's creation was inspired by meshing its best aerospace technology with its high-volume manufacturing capability. The TurboGenerator™ Power System was first developed as an electric power and water heating cogeneration system for the US Gas Research Institute. The technology next found its way into an under armor APU installed in US army tanks including being tested on the US Army's main battle tank, the M1A1. From there, the technology was applied to hybrid electric vehicles in the US with the Department of Energy and Ford and in France with Renault and Peugeot.
Standard

Turbine Flowmeter Fuel Flow Calculations

2013-10-04
HISTORICAL
ARP4990A
This SAE Aerospace Recommended Practice (ARP) provides to the aerospace industry a procedure for the consistent and accurate calculation of fuel flow using turbine flowmeters during development, production, and post overhaul/repair gas turbine engine testing.
Standard

Turbine Flowmeter Fuel Flow Calculations

2015-09-07
CURRENT
ARP4990B
This SAE Aerospace Recommended Practice (ARP) provides to the aerospace industry a procedure for the consistent and accurate calculation of fuel flow using turbine flowmeters during development, production, and post overhaul/repair gas turbine engine testing.
Technical Paper

Tribological Evaluation of the Aviation Kerosene for Use in CI Engines

2009-11-02
2009-01-2804
To reduce the fuel related logistic burden, NATO Armed Forces are advancing the use of a single fuel for both aircraft and ground equipment. To this end, F-34 is replacing distillate diesel fuel in many applications. Yet, unacceptable wear due to poor lubricity was illustrated by tests conducted with kerosene on High Frequency Reciprocating Rig. Therefore, HFRR tests were performed with fatty acid methyl esters of sunflower, palm, cotton-seed, tobacco-seed, olive, rape-seed and used frying oils, at volume concentrations from 0.05% to 0.6%. This study showed that the biodiesels used, produced a significant decrease in the wear scar diameter at concentrations of 0.2% to 0.4 %. Biodiesels derived from non-polyunsaturated oils, such as palm and olive gave better lubrication at certain concentrations.
Standard

Treatment of Sheet Metal Parts Corrosion-Resistant Steel

2017-09-20
CURRENT
AMS2550F
This specification covers the engineering requirements for a treatment to provide enhanced corrosion resistance to sheet metal parts, such as brackets, spacers, and washers, fabricated from martensitic Corrosion-resistant steels, usually AMS 5504 or AMS 5508 and having hardness not higher than 40 HRC, or ferritic corrosion-resistant steels, usually AMS 5506. The treatment is not recommended for use on parts subject to impact in service.
Standard

Treatment of Sheet Metal Parts Corrosion-Resistant Steel

1994-03-01
HISTORICAL
AMS2550E
This specification covers the engineering requirements for a treatment to provide enhanced corrosion resistance to sheet metal parts, such as brackets, spacers, and washers, fabricated from martensitic Corrosion-resistant steels, usually AMS 5504 or AMS 5508 and having hardness not higher than 40 HRC, or ferritic corrosion-resistant steels, usually AMS 5506. The treatment is not recommended for use on parts subject to impact in service.
X