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Standard

Retainers (Backup Rings), Hydraulic and Pneumatic, Polytetrafluoroethylene Resin, Solid, Un-Cut, For Use in AS4716 Glands

2015-04-06
HISTORICAL
AS5782A
This SAE Aerospace Standard (AS) covers solid, uncut polytetrafluoroethylene (PTFE) retainers (backup rings) for use in glands in accordance with AS4716. They are for use in hydraulic and pneumatic system components as anti-extrusion devices in conjunction with O-rings, packings and other elastomeric seals for static and dynamic applications. Because of the construction of groove dimensions, backup rings specific to rod applications are designated “R” - Rod (Female), backup rings specific to piston applications are designated “P” - Piston (Male). Piston and rod types of virgin pigmented PTFE are also identified by color code which also distinguishes parts to this standard from those made from virgin PTFE to other standards.
Technical Paper

Sulfur Impact on Methane Steam Reforming over the Stoichiometric Natural Gas Three-Way Catalyst

2024-04-09
2024-01-2633
The steam reforming of CH4 plays a crucial role in the high-temperature activity of natural gas three-way catalysts. Despite existing reports on sulfur inhibition in CH4 steam reforming, there is a limited understanding of sulfur storage and removal dynamics under various lambda conditions. In this study, we utilize a 4-Mode sulfur testing approach to elucidate the dynamics of sulfur storage and removal and their impact on three-way catalyst performance. We also investigate the influence of sulfur on CH4 steam reforming by analyzing CH4 conversions under dithering, rich, and lean reactor conditions. In the 4-Mode sulfur test, saturating the TWC with sulfur at low temperatures emerges as the primary cause of significant three-way catalyst performance degradation. After undergoing a deSOx treatment at 600 °C, NOx conversions were fully restored, while CH4 conversions did not fully recover.
Technical Paper

Methane Conversion in Stoichiometric Natural Gas Engine Exhaust

2024-04-09
2024-01-2632
Stoichiometric natural gas (CNG) engines are an attractive solution for heavy-duty vehicles considering their inherent advantage in emitting lower CO2 emissions compared to their Diesel counterparts. Additionally, their aftertreatment system can be simpler and less costly as NOx reduction is handled simultaneously with CO/HC oxidation by a Three-Way Catalyst (TWC). The conversion of methane over a TWC shows a complex behavior, significantly different than non-methane hydrocarbons in stoichiometric gasoline engines. Its performance is maximized in a narrow A/F window and is strongly affected by the lean/rich cycling frequency. Experimental and simulation results indicate that lean-mode efficiency is governed by the palladium’s oxidation state while rich conversion is governed by the gradual formation of carbonaceous compounds which temporarily deactivate the active materials.
Technical Paper

Highway Exhaust Emissions of a Natural Gas-Diesel Dual-Fuel Heavy-Duty Truck

2024-04-09
2024-01-2120
Diesel-fueled heavy-duty vehicles (HDVs) can be retrofitted with conversion kits to operate as dual-fuel vehicles in which partial diesel usage is offset by a gaseous fuel such as compressed natural gas (CNG). The main purpose of installing such a conversion kit is to reduce the operating cost of HDVs. Additionally, replacing diesel partially with a low-carbon fuel such as CNG can potentially lead to lower carbon dioxide (CO2) emissions in the tail-pipe. The main issue of CNG-diesel dual-fuel vehicles is the methane (CH4, the primary component of CNG) slip. CH4 is difficult to oxidize in the exhaust after-treatment (EAT) system and its slip may offset the advantage of lower CO2 emissions of natural gas combustion as CH4 is a strong greenhouse gas (GHG). The objective of this study is to compare the emissions of an HDV with a CNG conversion kit operating in diesel and dual-fuel mode during highway operation.
Technical Paper

Comparison of the Predictive Capabilities of Chemical Kinetic Models for Hydrogen Combustion Applications

2024-04-09
2024-01-2116
Recent legislation banning the sale of new petrol and diesel vehicles in Europe from 2035 has shifted the focus of internal combustion engine research towards alternative fuels with net zero tailpipe emissions such as hydrogen. Research regarding hydrogen as a fuel is particularly pertinent to the so-called ‘hard-to-electrify’ propulsion applications, requiring a combination of large range, fast refuelling times or high-load duty cycles. The virtual design, development, and optimisation of hydrogen internal combustion engines has resulted in the necessity for accurate predictive modelling of the hydrogen combustion and autoignition processes. Typically, the models for these processes rely respectively on laminar flame speed datasets to calculate the rate of fuel burn as well as ignition delay time datasets to estimate autoignition timing. These datasets are generated using chemical kinetic mechanisms available in the literature.
Technical Paper

Combustion Chamber Development for Flat Firedeck Heavy-Duty Natural Gas Engines

2024-04-09
2024-01-2115
The widely accepted best practice for spark-ignition combustion is the four-valve pent-roof chamber using a central sparkplug and incorporating tumble flow during the intake event. The bulk tumble flow readily breaks up during the compression stroke to fine-scale turbulent kinetic energy desired for rapid, robust combustion. The natural gas engines used in medium- and heavy-truck applications would benefit from a similar, high-tumble pent-roof combustion chamber. However, these engines are invariably derived from their higher-volume diesel counterparts, and the production volumes are insufficient to justify the amount of modification required to incorporate a pent-roof system. The objective of this multi-dimensional computational study was to develop a combustion chamber addressing the objectives of a pent-roof chamber while maintaining the flat firedeck and vertical valve orientation of the diesel engine.
Technical Paper

Experimental Study of Ammonia Combustion in a Heavy-Duty Diesel Engine Converted to Spark Ignition Operation

2024-04-09
2024-01-2371
Ammonia is one of the carbon-free alternatives considered for power generation and transportation sectors. But ammonia’s lower flame speed, higher ignition energy, and higher nitrogen oxides emissions are challenges in practical applications such as internal combustion engines. As a result, modifications in engine design and control and the use of a secondary fuel to initiate combustion such as natural gas are considered for ammonia-fueled engines. The higher-octane number of methane (the main component in natural gas) and ammonia allows for higher compression ratios, which in turn would increase the engine's thermal efficiency. One simple approach to initiate and control combustion for a high-octane fuel at higher compression ratios is to use a spark plug. This study experimentally investigated the operation of a heavy-duty compression ignition engine converted to spark ignition and ammonia-methane blends.
Standard

Recommended Practice for General Fuel Cell Vehicle Safety

2014-08-26
HISTORICAL
J2578_201408
This SAE Recommended Practice identifies and defines requirements relating to the safe integration of the fuel cell system, the hydrogen fuel storage and handling systems (as defined and specified in SAE J2579) and high voltage electrical systems into the overall Fuel Cell Vehicle. The document may also be applied to hydrogen vehicles with internal combustion engines. This document relates to the overall design, construction, operation and maintenance of fuel cell vehicles.
Standard

Standard for Fuel Systems in Fuel Cell and Other Hydrogen Vehicles

2018-06-15
HISTORICAL
J2579_201806
The purpose of this document is to define design, construction, operational, and maintenance requirements for hydrogen fuel storage and handling systems in on-road vehicles. Performance-based requirements for verification of design prototype and production hydrogen storage and handling systems are also defined in this document. Complementary test protocols (for use in type approval or self-certification) to qualify designs (and/or production) as meeting the specified performance requirements are described. Crashworthiness of hydrogen storage and handling systems is beyond the scope of this document. SAE J2578 includes requirements relating to crashworthiness and vehicle integration for fuel cell vehicles. It defines recommended practices related to the integration of hydrogen storage and handling systems, fuel cell system, and electrical systems into the overall Fuel Cell Vehicle.
Standard

Standard for Fuel Systems in Fuel Cell and Other Hydrogen Vehicles

2013-03-28
HISTORICAL
J2579_201303
The purpose of this document is to define design, construction, operational, and maintenance requirements for hydrogen fuel storage and handling systems in on-road vehicles. Performance-based requirements for verification of design prototype and production hydrogen storage and handling systems are also defined in this document. Complementary test protocols (for use in type approval or self-certification) to qualify designs (and/or production) as meeting the specified performance requirements are described. Crashworthiness of hydrogen storage and handling systems is beyond the scope of this document. SAE J2578 includes requirements relating to crashworthiness and vehicle integration for fuel cell vehicles. It defines recommended practices related to the integration of hydrogen storage and handling systems, fuel cell system, and electrical systems into the overall Fuel Cell Vehicle.
Standard

Low Speed Vehicles

2010-09-29
HISTORICAL
J2358_201009
This SAE Standard defines the safety and performance requirements for Low Speed Vehicles (“LSV”). The safety specifications in this document apply to any powered vehicle with a minimum of 4-wheels, a maximum level ground speed of more than 32 km/h (20 mph) but not more than 40 km/h (25 mph),), and a maximum gross vehicle weight of 1361 kg (3000 lb), that is intended for operating on designated roadways where permitted by law.
Standard

Low Speed Vehicles

2016-11-18
HISTORICAL
J2358_201611
This SAE Standard defines the safety and performance requirements for Low Speed Vehicles (“LSV”). The safety specifications in this document apply to any powered vehicle with a minimum of 4-wheels, a maximum level ground speed of more than 32 km/h (20 mph) but not more than 40 km/h (25 mph),), and a maximum gross vehicle weight of 1361 kg (3000 pounds), that is intended for operating on designated roadways where permitted by law.
Standard

Low Speed Vehicles

2002-03-20
HISTORICAL
J2358_200203
This SAE Standard defines the safety and performance requirements for Low Speed Vehicles (“LSV”). The safety specifications in this document apply to any powered vehicle with a minimum of 4-wheels, a maximum level ground speed of more than 32 km/h (20 mph) but less than 40 km/h (25 mph), a maximum rated capacity of 500 kg (1100 lb), and a maximum gross vehicle weight of 1135 Kg (2500 lb), that is intended for transporting not more than four (4) persons and operating on designated roadways where permitted by law. Personal Neighborhood Vehicles (PNVs) have the same general specifications as LSVs, but the maximum level ground speed is limited to 32 km/h (20 mph).
Standard

Low-Speed Vehicles

2022-08-19
CURRENT
J2358_202208
This SAE Standard defines the safety and performance requirements for low-speed vehicles (LSVs). The safety specifications in this document apply to any powered vehicle with a minimum of four wheels, a maximum level ground speed of more than 32 km/h (20 mph) but not more than 40 km/h (25 mph), and a maximum gross vehicle weight of 1361 kg (3000 pounds), that is intended for operating on designated roadways where permitted by law.
Technical Paper

Further Experiments on the Effects of In-Cylinder Wall Wetting on HC Emissions from Direct Injection Gasoline Engines

1999-10-25
1999-01-3661
A recently developed in-cylinder fuel injection probe was used to deposit a small amount of liquid fuel on various surfaces within the combustion chamber of a 4-valve engine that was operating predominately on liquefied petroleum gas (LPG). A fast flame ionization detector (FFID) was used to examine the engine-out emissions of unburned and partially-burned hydrocarbons (HCs). Injector shut-off was used to examine the rate of liquid fuel evaporation. The purpose of these experiments was to provide insights into the HC formation mechanism due to in-cylinder wall wetting. The variables investigated were the effects of engine operating conditions, coolant temperature, in-cylinder wetting location, and the amount of liquid wall wetting. The results of the steady state tests show that in-cylinder wall wetting is an important source of HC emissions both at idle and at a part load, cruise-type condition. The effects of wetting location present the same trend for idle and part load conditions.
Journal Article

Applying the Hilbert Envelope Method to Refine the Ultrasonic Technique for Piston Ring Oil Film Thickness Measurements in a Marine Diesel Engine

2022-04-21
Abstract The greatest frictional contributor in an internal combustion engine is the contact between the piston ring pack and cylinder liner. Therefore, an improved lubrication regime has the potential to raise engine efficiency while lowering emissions, aiding to meet environmental regulations. Previous ultrasonic measurements of the oil film thickness (OFT) between piston rings and the cylinder liner in a marine engine have been subject to several unexpected trends. This article refines the measurement to identify and remove these factors, the trends were found to have arisen due to the detection of ultrasonic reflections from the piston ring outside of the expected alignment zone. The extent of these undesired reflections is thought to be due to the liner thickness providing a relatively large distance for spreading of the ultrasonic wavefront.
Technical Paper

Glow-discharge Optical Emission Spectroscopy Study of Cr(III) Sealing in Anodized Aluminium-Silicon Alloys for Brake Component

2024-09-08
2024-01-3038
Calipers and pistons for high-end car braking systems are typically realized using anodized Aluminium-Silicon alloys. Indeed, Aluminium-Silicon alloys are light materials with optimal mechanical properties and, when anodized, excellent corrosion and wear resistances. To achieve these top-notch surface properties, the anodizing process is followed by a sealing post-treatment, which significantly improves the corrosion resistance and tunes the tribological properties (e.g., hardness and friction coefficient) of the anodized pieces. Sealing consists in the precipitation of insoluble hydroxides and functional compounds (e.g., corrosion inhibitors) inside the nano-pores of the anodic layer. Nevertheless, sealing might not penetrate through all the nano-porous structure of the anodic layer. Thus, in light of possible post-machining of sealed, anodized components, it appears fundamental to develop a tool to determine the depth penetration of sealing inside the anodic layer.
Book

Allied Aircraft Piston Engines of World War II, 2nd Edition

2019-05-16
Allied Aircraft Piston Engines of World War II, now in its second edition, coalesces multiple aspects of war-driven aviation and its amazing technical accomplishments, leading to the allied victory during the second world war. Not by chance, the air battles that took place then defined much of the outcome of one of the bloodiest conflicts in modern history. Forward-thinking airplane design had to be developed quickly as the war raged on, and the engines that propelled them were indeed the focus of intense cutting-edge engineering efforts. Flying higher, faster, and taking the enemy down before they even noticed your presence became a matter of life or death for the allied forces. Allied Aircraft Piston Engines of World War II, Second Edition, addresses British- and American-developed engines. It looks at the piston engines in detail as they supported amazing wins both in the heat of the air battles, and on the ground supplying and giving cover to the troops.
Journal Article

Numerical Simulation of Turbulent Structures Inside Internal Combustion Engines Using Large Eddy Simulation Method

2023-10-16
Abstract Using two subgrid-scale models of Smagorinsky and its dynamic version, large eddy simulation (LES) approach is applied to develop a 3D computer code simulating the in-cylinder flow during intake and compression strokes in an engine geometry consisting of a pancake-shaped piston with a fixed valve. The results are compared with corresponding experimental data and a standard K-Ɛ turbulence model. LES results generally show better agreement with available experimental data suggesting that LES with dynamic subgrid-scale model is more effective method for accurately predicting the in-cylinder flow field.
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