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Technical Paper

A Study on Combustion and Emission Characteristics of an Ammonia-Biodiesel Dual-Fuel Engine

Internal combustion engines, as the dominant power source in the transportation sector and the primary contributor to carbon emissions, face both significant challenges and opportunities in the context of achieving carbon neutral goal. Biofuels, such as biodiesel produced from biomass, and zero-carbon fuel ammonia, can serve as alternative fuels for achieving cleaner combustion in internal combustion engines. The dual-fuel combustion of ammonia-biodiesel not only effectively reduces carbon emissions but also exhibits promising combustion performance, offering a favorable avenue for future applications. However, challenges arise in the form of unburned ammonia (NH3) and N2O emissions. This study, based on a ammonia-biodiesel duel-fuel engine modified from a heavy-duty diesel engine, delves into the impact of adjustments in the two-stage injection strategy on the combustion and emission characteristics.
Technical Paper

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

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.
Technical Paper

Ignition System Measurement Techniques and Correlations for Breakdown and Arc Voltages and Currents

The first part of the paper is a brief review of the techniques needed for measuring the voltage and current during the ignition process. These techniques have been used in test rigs and an engine to gain insights into the breakdown and subsequent discharge development. New correlations are presented for breakdown voltage as functions of spark plug gap, gas composition, temperature and pressure. The discharge voltage is affected by the flow, so an elevated pressure flow rig was used to look at the effect of flow and pressure on the discharge voltage history, with different stored energies in the ignition coil. This study led to a model for the discharge voltage history, from which it was possible to deduce the flow velocity through the spark plug gap. Finally, these techniques were applied to a single cylinder, 4-valve, pent-roof combustion chamber SI engine, for determining the cycle-by-cycle variations in velocity through the spark plug at the time of ignition.
Technical Paper

Development of Ammonia Direct Injection 4-Cylinder Spark-Ignition Engine

As the carbon neutrality to reduce greenhouse gas emissions has become a global movement, the development of power sources using carbon-free fuels is an essential task for the industry. Accordingly, many companies in various fields that need carbon reduction are striving to develop power sources and build energy value chains using carbon-free or carbon-neutral fuels such as hydrogen and E-fuel. Ammonia, which is also a carbon-free fuel, stands as an efficient energy vector delivering high energy density and flexibility in transportation and storage, capable of mitigating hydrogen’s key drawbacks. However, difficulty of controlling combustion of ammonia due to its fuel characteristics limited the development of internal combustion engines using ammonia to the basic research stage in the limited operating conditions. Hyundai Motor Company presents the development of ammonia fueled 4-cylinder SI engine using direct injection strategy, designed based on 2.5L LPG T-DI engine.

Taxonomy and Classification of Powered Micromobility Vehicles

This technical report provides a taxonomy and classification of powered micromobility vehicles. These vehicles may be privately owned or be available via shared- or rental-fleet operations. This technical report does not provide specifications or otherwise impose minimum safety design requirements for powered micromobility vehicles.
Journal Article

Review of Gas Generation Behavior during Thermal Runaway of Lithium-Ion Batteries

Abstract Due to the limitations of current battery manufacturing processes, integration technology, and operating conditions, the large-scale application of lithium-ion batteries in the fields of energy storage and electric vehicles has led to an increasing number of fire accidents. When a lithium-ion battery undergoes thermal runaway, it undergoes complex and violent reactions, which can lead to combustion and explosion, accompanied by the production of a large amount of flammable and toxic gases. These flammable gases continue to undergo chemical reactions at high temperatures, producing complex secondary combustion products. This article systematically summarizes the gas generation characteristics of different types and states of batteries under different thermal runaway triggering conditions. And based on this, proposes the key research directions for the gas generation characteristics of lithium-ion batteries.
Technical Paper

Influence of Intake Charge Temperature and EGR Rate on the Combustion and Emission Characteristics of Ammonia/Diesel Dual-Fuel Engine

Ammonia has emerged as a promising carbon-free alternative fuel for internal combustion engines (ICE), particularly in large-bore engine applications. However, integrating ammonia into conventional engines presents challenges, prompting the exploration of innovative combustion strategies like dual-fuel combustion. Nitrous oxide (N2O) emissions have emerged as a significant obstacle to the widespread adoption of ammonia in ICE. Various studies suggest that combining exhaust gas recirculation (EGR) with adjustments in inlet temperature and diesel injection timing can effectively mitigate nitrogen oxides (NOx) emissions across diverse operating conditions in dual-fuel diesel engines.
Technical Paper

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

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.
Technical Paper

A Study of the Thermochemical Conditions in the Exhaust Manifold Using Secondary Air in a 2.0 L Engine

The California LEV1 II program will be introduced in the year 2003 and requires a further reduction of the exhaust emissions of passenger cars. The cold start emissions represent the main part of the total emissions of the FTP2-Cycle. Cold start emissions can be efficiently reduced by injecting secondary air (SA) in the exhaust port making compliance with the most stringent standards possible. The thermochemical conditions (mixing rate and temperature of secondary air and exhaust gas, exhaust gas composition, etc) prevailing in the exhaust system are described in this paper. This provides knowledge of the conditions for auto ignition of the mixture within the exhaust manifold. The thus established exothermal reaction (exhaust gas post-combustion) results in a shorter time to light-off temperature of the catalyst. The mechanisms of this combustion are studied at different engine idle conditions.
Journal Article

A Novel Technique for Measuring Cycle-Resolved Cold Start Emissions Applied to a Gasoline Turbocharged Direct Injection Engine

There is keen interest in understanding the origins of engine-out unburned hydrocarbons emitted during SI engine cold start. This is especially true for the first few firing cycles, which can contribute disproportionately to the total emissions measured over standard drive cycles such as the US Federal Test Procedure (FTP). This study reports on the development of a novel methodology for capturing and quantifying unburned hydrocarbon emissions (HC), CO, and CO2 on a cycle-by-cycle basis during an engine cold start. The method was demonstrated by applying it to a 4 cylinder 2 liter GTDI (Gasoline Turbocharged Direct Injection) engine for cold start conditions at an ambient temperature of 22°C. For this technique, the entirety of the engine exhaust gas was captured for a predetermined number of firing cycles.

Procedure for Measuring Bore and Face Runout of Flywheels, Flywheel Housings, and Flywheel Housing Adapters

This SAE Recommended Practice applies to any internal combustion engine which can utilize SAE No. 6 thru SAE No. 00 size flywheel housing. It provides instructions for correcting flywheel housing bore runout readings which are influenced by crankshaft bearing clearance. Limits for bore and face runout are specified in the various SAE Standards and Recommended Practices covering flywheels and flywheel housings.
Journal Article

Pre-Ignition Characteristics of Ethanol and E85 in a Spark Ignition Engine

Ethanol based fuels have seen increased use in recent years due to their renewable nature as well as increased governmental regulatory mandates. While offering performance advantages over gasoline, especially at high compression ratios, these fuels are more sensitive to pre-ignition (PI). Pre-ignition experiments using ethanol (E100) and E85 were performed in a CFR spark ignition engine using a diesel glow plug “hot spot” to induce PI. PI is found to occur over a specific air-fuel ratio range based on hot spot temperature. Additionally, increasing ethanol content or compression ratio (CR) decreases glow plug temperature thresholds for PI. A kinetics-based model was used to simulate pre-ignition of E100 and to elucidate sensitivities of pre-ignition to various operating parameters, including initial charge temperature, air dilution, and residual dilution. The model shows that the most violent cases of PI can be mitigated by switching to either lean or rich operation.

SAE Truck & Off-Highway Engineering: April 2018

Connectivity takes center stage Telematic links have become the norm, helping fleet owners and operators improve efficiency and letting OEMs predict component failures. More power, less noise, fewer emissions These key attributes drive development of new generators both big and small. TARDEC pursues advanced power generation U.S. Army, GM collaborate on fuel-cell-generated electricity to power the vehicle's propulsion system and onboard electronics, while providing off-vehicle power via an Exportable Power Take-Off unit. Developing an alternative engine concept Ricardo's CryoPower engine leverages two unique combustion techniques for reduced emissions and fuel consumption-liquid nitrogen and split combustion. Long-haul trucking and stationary power generation will be the first beneficiaries of the technologies. Technology time-warp The road to autonomous driving has been under construction for decades, as showcased by SAE's Mobility History Committee at the 2018 WCX in Detroit.

Automotive Engineering: November 3, 2015

Active in aero Several automakers-notably Mercedes-Benz and Audi - used the Frankfurt Motor Show stage to reveal sleek vehicles that aggressively employ active aerodynamic elements and other advances to reduce drag. Composites permeate inside and out Composite materials are gaining popularity for both unseen structural components and for exterior eye candy. Powertrain testing: coping with complexity With increasing use of electrical components to extend the performance of conventional combustion engines, powertrain development has never been more complicated. The good news is that test and development engineers are harnessing advanced simulation techniques and computer processing to develop the most efficient and fun powertrains ever. Can ads help in vehicle-to-vehicle rollout? Porsche unveils new downsized, boosted 3.0-L boxer six. Johnson Controls, Faurecia envision interiors for autonomous driving. Jaguar enters performance crossover SUV segment.

SAE International debuts AS13006, Process Control Methods aerospace standard

SAE International in Warrendale, Pa., has published AS13006: Process Control Methods, a new standard with guidance material to support specific aerospace engine applications, with a focus on the practical application of control methods for many different situations, to improve process control, process capability, and product quality, benefiting both the organization applying it and its customers.

Automotive Engineering: May 2017

Innovations for lightweighting Tough fuel-economy bogies for 2021 and beyond are driving new approaches to materials use, as seen in these case studies. Axellent progress AAM's new Quantum drive-axle technology is a leap forward in lightweight, efficient driveline systems aimed at 2020 and beyond. Low-temperature combustion ready for prime time? At SAE's High-Efficiency IC Engines Symposium, Delphi said its new, third-generation GDCI is promising, but even LTC proponents admit that challenges remain. More automation for ECU testing The latest fault-insertion tests enable engineers to run more test cases in less time.

SAE Truck & Off-Highway Engineering: August 2017

Collaborating on diesel emission control Stringent fuel-efficiency and criteria-pollutant standards call for new combustion strategies. The SwRI-led Advanced Combustion Catalyst and Aftertreatment Technologies consortium reinvents existing technologies and experiments with new catalysts to meet standards. More intelligence equals more efficiency, enhanced functionality Advanced systems require renewed focus on architectures, processors, sensors and networks. Appraising the potential for platooning in the U.S. Researchers from the National Renewable Energy Laboratory perform statistical analysis based on a large collection of real-world U.S. truck usage data to estimate the fraction of total miles that are technically suitable for platooning. Connected commercial vehicles bring cybersecurity to the fore Connectivity, automation and electrification will largely drive vehicle developments in the coming years, according to experts presenting at the revamped SAE COMVEC 17.


Knowledge wins at 2017 Formula SAE Lincoln The University of Pennsylvania and Texas A&M win the Electric and Internal Combustion Classes, respectively. Flying high at SAE Aero Design New for the twin 2017 competitions in Texas and Florida was a requirement for planes registered in the Regular Class to carry "passengers." Pedal to the metal at Formula SAE Michigan More than 100 university teams compete in this premier student racecar design competition combining static and dynamic events. Removing bumps on the path to fully automated driving Inaugural workshop for new AutoDrive Challenge student competition held at SAE World Headquarters.

Automotive Engineering: April 2018

Engineering the Motivo Way Broad capabilities, unparalleled project diversity and an innovative culture have put this thriving California "idea factory" in high demand. Steering toward lower NVH Systems-based analysis at Saint-Gobain shows how a small part can make a big difference to steering, and to overall vehicle quality. Not dead yet: The resilient ICE looks to 2050 The mobility industry will need to keep evolving the combustion engine for many years, says Dr. John Heywood. Technology time-warp The road to autonomous driving has been under construction for decades, as showcased by SAE's Mobility History Committee at the 2018 WCX in Detroit.