Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

Simulation Analysis of the Dynamics Characteristics of Battery Electric Vehicle Transmission System under Impact Condition

2024-04-09
2024-01-2719
This paper analyzes the dynamic characteristics of transmission system of battery electric vehicle through simulations, the research method and conclusions can serve as a theoretical basis and reference for the design of vehicle system architecture.To accurately describe the torsional vibration characteristics of battery electric vehicle's transmission system, it is necessary to reasonably simplify the system, furthermore, when subjected to short-wave uneven road surface excitation, the connection between the rigid ring in the SWIFT model and the ground belongs to single-point contact and cannot represent the tire enveloping properties.Around the above issues, a method has been proposed to simplify the gearbox model into a force-coupled model with centralized damping, stiffness, and mass, along with an equivalent road surface model consisting of elliptical cams in series that can represent tire enveloping propertie, correspondongly,an evaluation criterion has been established, which utilizes the ratio of the peak torque of the impact force at the rear wheel hub after encountering a step to the maximum output torque of the gearbox as the impact coefficient.In four-wheel-drive vehicle models, the impact coefficient of the front axle is greater than that of the rear axle when going uphill, and when going downhill, the impact coefficient of the rear axle is greater than that of the front axle, for another, in both uphill and downhill scenarios, the impact coefficient of the four-wheel-drive vehicle model is greater than that of the front-wheel-drive and rear-wheel-drive models.
Technical Paper

Ducted Fuel Injection: Confirmed re-entrainment hypothesis

2024-04-09
2024-01-2885
Testing of ducted fuel injection (DFI) in a single-cylinder engine with production-like hardware previously showed that simply adding a duct structure increased soot emissions at the full load, rated speed operating point. In the authors’ 2021 SAE paper, which reported these findings, it was hypothesized that the DFI flame, which is faster than a conventional diesel combustion (CDC) flame, and has a shorter distance to travel, was being re-entrained into the on-going injection around the lift-off length, thus reducing air entrainment into the on-going injection. The engine operating condition and the engine combustion chamber geometry were duplicated in a constant pressure vessel. The experimental setup used a 3D piston section combined with a glass fire deck allowing for a comparison between a CDC flame and a DFI flame via high-speed imaging. Testing clearly confirmed the detrimental effect of the DFI flame re-entrainment hypothesis presented in the previous on-engine work.
Technical Paper

Pre-chamber Combustion System Development for an Ultra-lean Gasoline Engine

2024-04-09
2024-01-2110
Amid rising demands for fuel efficiency and emissions reduction, enhancing the thermal efficiency of gasoline engines has become imperative, which requires higher efficiency combustion strategies and integrated optimized design to maximize the work output from fuel. In gasoline engines, both increasing the compression ratio and using lean burn mode improve the thermal efficiency effectively. Although there is limited scope for increasing the compression ratio due to the higher sensitivity to knocking, especially under stoichiometric conditions, reduced sensitivity could be got with leaner mixture fill into cylinder, which can further increase the specific heat ratio and thermal efficiency. However, realizing the efficiency benefits of lean burn in gasoline engines necessitates overcoming critical challenges like ensuring robust ignition process and accelerating burning rates to achieve short, stable combustion durations.
Technical Paper

Evolution of Light-duty Gasoline Compression Ignition (LD-GCI) for High Efficiency and US Tier3- Bin30 Emissions

2024-04-09
2024-01-2092
It is widely recognized that internal combustion engines (ICE) are needed for global transport for years to come, however, demands on ICE fuel efficiency, emissions, cost, and performance are extremely challenging. Gasoline compression ignition (GCI) is one approach to achieving demanding efficiency and emissions targets. At Aramco Research Center-Detroit, an advanced, multi-cylinder GCI engine was designed and built using the latest combustion system, engine controls, and lean aftertreatment. The combustion system uses Aramco's PPCI-diffusion process for ultra-low NOx and smoke. A P2 48V mild hybrid system was integrated on the engine for braking energy recovery and improved cold starts. For robust low-load operation, a 2-step valvetrain system was used for exhaust rebreathing. The fuel injection system was a modified diesel system with high injection rate and 2000 bar pressure rating.
Technical Paper

Proactive Battery Energy Management using Navigation Information

2024-04-09
2024-01-2142
In this paper, a control strategy for state of charge (SOC) allocation using navigation data for Hybrid Electric Vehicle (HEV) propulsion systems is proposed. This algorithm dynamically defines and adjusts a SOC target as a function of distance travelled on-line, thereby enabling proactive management of the energy store in the battery. The proposed approach incorporates variances in road resistance and adheres to geolocation constraints, including ultra-low emission zones (uLEZ). The anticipated advantages are particularly pronounced during scenarios involving extensive medium-to-long journeys characterized by abrupt topological changes or the necessity for exclusive electric vehicle (EV) mode operation. This novel solution stands to significantly enhance both drivability and fuel economy outcomes.
Technical Paper

Light Duty engine performance characteristics with Dimethyl Ether and Propane

2024-04-09
2024-01-2126
Paper documents the performance characteristics of a compression ignition HYUNDAI 2.2L engine operating with Dimethyl Ether (DME) and Propane mixtures. The engine features a high-pressure common rail fuel injection system designed to operate with DME and Propane. The main component of the fuel system is a high-pressure pump that incorporates an electronic inlet metering valve commanded on a crank angled base to control the rail pressure. The pump, which requires no pressure regulator, provides the flow needed to the injectors without flow returning to the inlet. Tests are carried out at injection pressures from 300bar to 1000bar, and the engine ECU is aided with the use of an Engine Controller High speed Oversight unit (ECHO) to provide combustion phasing control and improved cylinder-to-cylinder uniformity, providing improved optimization over the testing effort.
Technical Paper

Evaluating the effects of an Electrically Assisted Turbocharger on scavenging control for an Opposed Piston Two Stroke (OP2S) compression ignition engine

2024-04-09
2024-01-2388
Opposed piston two-stroke (OP2S) diesel engines have demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Due to the higher thermal efficiency and absence of a cylinder head, the heat transfer loss to the coolant is lower near the ‘Top Dead Center’. The selection and design of the airpath are pivotal in realizing the benefits of the OP2S engine architecture. Like any two-stroke diesel engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Moreover, a significant portion of the work involved in pumping air is carried out externally to the engine cylinder which needs to be accounted for when calculating brake efficiencies.
Technical Paper

3-Dimentional Numerical Transient Simulation and Research on Flow Distribution Unevenness in Intake Manifold for a Turbocharged Diesel Engine

2024-04-09
2024-01-2420
The design of engine intake system affects the intake uniformity of each cylinder of the engine, which in turn has an important impact on the engine performance, the uniform distribution of EGR exhaust gas and the combustion process of each cylinder. In this paper, the constant-pressure supercharged diesel engine intake pipe is used as the research model to study the intake air flow unevenness of the intake pipe of the supercharged diesel engine. The pressure boundary condition at the outlet of each intake manifold is set as the dynamic pressure change condition. The three-dimensional numerical simulation of the transient flow process in the intake manifold of diesel engine is simulated and analyzed by using numerical method, and the change of the internal flow field in the intake manifold under different working conditions during the intake overlapping period is discussed.
Technical Paper

Modeling of the EcoCAR electric vehicle for torque split analysis and architecture selection

2024-04-09
2024-01-2166
The proliferation of electric vehicles (EVs) is making big transition in the automotive industry, promising reduced greenhouse gas emissions and improved energy efficiency. The architectural configurations and power distribution strategies necessitate the optimization of their drivability performance, all-electric ranges, and overall efficiency. This paper reports the efforts of the University of California at Riverside (UCR) EcoCAR team in EV architecture selection to match the EcoCAR EV Challenge theme of shared mobility for disadvantaged communities. The UCR EcoCAR team conducted a comprehensive analysis of various EV architectures (including rear-wheel drive, front-wheel drive, and all-wheel drive) and motor parameters, considering a spectrum of targeted vehicle technology specifications such as acceleration and braking performance, fuel economy, and cargo/passenger capacity.
Technical Paper

On the Need for Revisions of Utility Factor Curves for Plug-in Hybrids in the US

2024-04-09
2024-01-2155
Plug-in hybrid electric vehicles (PHEVs) have the capability to drive an appreciable fraction of their miles travelled on electric power from the grid, similar to battery-only electric vehicles (BEVs). However, unlike BEVs which cannot drive unless charged, PHEVs can automatically switch to gasoline power and operate similar to a regular (non-plug-in) hybrid electric vehicle (HEV). Though operating similar to HEV is already beneficial in terms of fuel economy, greenhouse gas (GHG) emissions and criteria pollutants compared to conventional internal combustion engine (ICE) vehicles, much of the attractiveness and allure of PHEVs comes from their capability to drive “almost like a BEV”, but without range anxiety about running out of battery charge.
Technical Paper

Analysis of Dual Fuel Hydrogen/Diesel Combustion Varying Diesel and Hydrogen Injection Parameters in a Single Cylinder Research Engine

2024-04-09
2024-01-2363
In the perspective of a reduction of emissions and a rapid decarbonization, especially for compression ignition engines, hydrogen plays a decisive role. The dual fuel technology is perfectly suited to the use of hydrogen, a fuel characterized by great energy potential. In fact, replacing, at the same energy content, the fossil fuel with a totally carbon free one, a significant reduction of the greenhouse gases, like carbon dioxide and total hydrocarbon, as well as of the particulate matter can be obtained. The dual fuel with indirect injection of gaseous fuel in the intake manifold, involves the problem of hydrogen autoignition. In order to avoid this difficulty, the optimal conditions for the injection of the incoming mixture into the cylinder were experimentally investigated. All combustion processes have been carried out on a research engine with optical access. The engine speed has been set at 1500 rpm, while the EGR valve has been deactivated.
Technical Paper

Decarbonizing Light Vehicles with Hydrous Ethanol: Performance Analysis of a Range-Extended PHEV Using Experimental and Simulation Techniques

2024-04-09
2024-01-2161
Plug-in hybrid electric vehicles have the potential of combining the benefits of electric vehicle in terms of low emissions and internal combustion engine vehicles in terms of vehicle range. With the addition of a renewable fuel, the CO2 potential reduction increase even more. The last trends for PHEV are small combustion engine known as range extender, with battery package between full hybrid and electric powertrains. Thus, allowing an improvement in vehicle’s range, reducing battery materials while converting fuel energy through a highly efficient path. Although these vehicles have been proved to be a convenient strategy for decarbonizing the light vehicles, the use of alternative fuels is poorly studied. In this work, hydrous ethanol is chosen because is already available in some countries, such as USA and Brazil, and have an ultra-low well-to-tank CO2 emission.
X