Refine Your Search

Topic

Author

Affiliation

Search Results

Technical Paper

A Novel Vehicle-to-Vehicle Fast Charging Control System Utilizing Motor and Inverter in EV

2022-03-29
2022-01-0170
As electric vehicles become more widespread, such vehicles may be subject to “range anxiety” due to the risk of discharging during driving or the discharging when left unused for a long period. Accordingly, a vehicle equipped with a mobile charger that can provide a charge in an emergency. The vehicle with the mobile charger is usually composed of a large capacity battery, a power converter in a small truck. However, the large capacity battery and the power converter are disadvantageous in that they are large in size and expensive and should be produced as a special vehicle. In this paper, we propose a method to solve the problem using an internal EV system without requiring an additional power generation, battery and a charging-and-discharging device. The method is a novel Vehicle-to-Vehicle fast charging control system utilizing motor and inverter in EV.
Technical Paper

Vehicle Feature Recognition Method Based on Image Semantic Segmentation

2022-03-29
2022-01-0144
In the process of truck overload and over-limit detection, it is necessary to detect the characteristics of the vehicle's size, type, and wheel number. In addition, in some vehicle vision-based load recognition systems, the vehicle load can be calculated by detecting the vibration frequency of specific parts of the vehicle or the change in the length of the suspension during the vehicle's forward process. Therefore, it is essential to quickly and accurately identify vehicle features through the camera. This paper proposes a vehicle feature recognition method based on image semantic segmentation and Python, which can identify the length, height, number of wheels and vibration frequency at specific parts of the vehicle based on the vehicle driving video captured by the roadside camera.
Technical Paper

Databased modeling: An AI Toolchain for the development process of combustion engines

2022-03-29
2022-01-0158
Predictive physical modeling is an established method used in the development process for any automotive component or system. While accurate predictions can be issued after tuning model parameters, long computation times can be expected depending on the complexity of the model at hand. As the requirements of the components/systems to be developed continuously increase, new optimization approaches are constantly being applied to solve multidimensional objectives and resulting conflicts optimally. Unfortunately, some of those approaches are deemed not feasible, as the computational times of the required single predictions using conventional simulation models are too high. Therefore, it is proposed to use data-based models such as trained neural networks instead of physical models to address this issue. Previous efforts have failed due to a weak database and the resulting poor predictive ability of data-based models.
Technical Paper

CFD Simulation of Oil Jet Piston Cooling Applied to Pistons with Cooling Gallery

2022-03-29
2022-01-0210
Efficient cooling of the pistons with oil jets can avoid engine failures due to exceeded piston temperatures of thermally high-loaded combustion engines and can contribute to fuel consumption savings. To reduce expensive and time-consuming engine testing during product development, computational fluid dynamics (CFD) simulations help to quantify the piston cooling performance and gain detailed insights into the complex interactions between oil, air, and piston already in the design phase. The durability of new piston design approaches such as integrated advanced cooling galleries or highly resistant materials like steel can be evaluated including the use of alternative fuels such as compressed natural gas (CNG), hydrogen, alcohols, or e-fuels. A new CFD simulation model and methodology for oil-jet piston cooling has been developed to investigate the cooling efficiency considering various piston cooling geometries and operational parameters.
Technical Paper

Model in the loop control strategy evaluation procedure for an autonomous parking lot sweeper

2022-03-29
2022-01-0086
A path tracking controller is essential for an autonomous vehicle to navigate a complex environment while avoiding obstacles. Many research studies have proposed new controller designs and strategies. However, it is often unclear which control strategy is the most suitable for a specific Autonomous / ADAS user application. This study proposes a benchmark workflow by comparing different control observer models and their control strategies integration for an autonomous parking lot sweeper in a complex and dense environment at low-speed utilizing model-in-the-loop simulation. The systematic procedure consists of the following steps: (1) vehicle observer model validation (2) control strategy development (3) model-in-the-loop simulation benchmark for specific user scenarios. The kinematic and dynamic vehicle models were used to validate the truck’s behavior using physical data.
Technical Paper

Development of a Reduced TPRF-E (heptane/isooctane/toluene/ethanol) Gasoline Surrogate Model for Computational Fluid Dynamic Applications in Engine Combustion and Sprays

2022-03-29
2022-01-0407
Investigating combustion characteristics of oxygenated gasoline and gasoline blended ethanol is a subject of recent interest. The non-linearity in the interaction of fuel components in the oxygenated gasoline can be investigated by developing chemical kinetics of relevant surrogate of fewer components. This work proposes a new reduced four-component (isooctane, heptane, toluene, and ethanol) oxygenated gasoline surrogate mechanism consisting of 67 species and 325 reactions, applicable for dynamic CFD applications in engine combustion and sprays. The model introduces the addition of eight C1 species into the previous model (Yang et al;2019) followed by extensive tuning of reaction rate constants of C7 – C8 chemistry. The current mechanism delivers excellent prediction capabilities in comprehensive combustion applications with an improved performance in lean conditions.
Technical Paper

Advanced finite-volume numerics and source term assumptions for G-Equation modelling of propane/air flames

2022-03-29
2022-01-0406
G-Equation models represent propagating flame fronts with an implicit two-dimensional surface representation (level-set). Level-set methods are fast, as transport source terms for the implicit surface can be solved with finite-volume operators on the finite-volume domain, without having to build the actual surface. However, they carry out several approximations and assumptions whose practical impact on the accuracy of combustion simulations is often not properly understood. In this study, we analyzed all source terms making up the FRESCO CFD code’s G-Equation solver for simulating propane/air flames. We employed three well-established constant-volume configurations: a one-dimensional, freely-propagating laminar flame; a disc-shaped, constant-volume swirl combustor; and torch-jet flame development through an orifice from a two-chamber device. We tested the explicit (sub-cycled) vs. implicit formulation for the standard transport operators (advection, diffusion, compressibility).
Technical Paper

A Study of Propane Combustion in a Spark-ignited Cooperative Fuel Research (CFR) Engine

2022-03-29
2022-01-0404
Liquefied petroleum gas (LPG), whose primary composition is propane, is a promising candidate for heavy-duty vehicle applications as a diesel fuel alternative due to its CO2 reduction potential and high knock resistance. To realize diesel-like efficiencies, spark-ignited LPG engines are proposed to operate near knock-limit over a wide range of operating conditions, which necessitates an investigation of fuel-engine interactions that leads to end-gas autoignition with propane combustion. This work presents both experimental and numerical studies of stoichiometric propane combustion in a spark-ignited cooperative fuel research (CFR) engine. Engine experiments are initially conducted at two different compression ratios (CR), and the effects of CR on engine combustion are characterized. A three-pressure analysis (TPA) model based on the two-zone combustion concept is developed in GT-Power and validated using test results to estimate cylinder wall temperatures, residual gas fraction, etc.
Technical Paper

Modeling Fuel-Air Mixing, Combustion and Soot Formation with Ducted Fuel Injection Using Tabulated Kinetics

2022-03-29
2022-01-0403
Ducted Fuel Injection (DFI) has the potential to reduce soot emissions in Diesel engines thanks to the enhanced mixing rate resulting from the liquid fuel flow through a small cylindrical pipe located at a certain distance from the nozzle injector hole. A consolidated set of experiments in constant-volume vessel and engine allowed to understand the effects of ambient conditions, duct geometry and shape on fuel-air mixing, combustion and soot formation. However, implementation of this promising technology in compression-ignition engines requires predictive numerical models that can properly support the design of combustion systems in a wide range of operating conditions. This work presents a computational methodology to predict fuel-air mixing and combustion with ducted fuel injection. Attention is mainly focused on turbulence and combustion modelling.
Technical Paper

A Comparison of Isobaric and Conventional Diesel Combustion using High-Speed Optical Imaging

2022-03-29
2022-01-0418
Isobaric combustion can achieve higher thermal efficiency, lower heat transfer losses, and NOx emissions compared to conventional diesel combustion (CDC). Previous studies on isobaric combustion provided a detailed analysis of performance/emissions characteristics with a limited emphasis on the fuel-air mixing process, high-temperature reaction, and soot formation zones. In the present study, high-speed imaging of Mie-scattering, CH* chemiluminescence, and soot luminosity were conducted in an optically accessible single-cylinder heavy-duty diesel engine for CDC and isobaric combustion. The fuel used for both the combustion modes is n-heptane, which is a surrogate of diesel fuel. The engine was equipped with a flat-bowl shaped optical piston to allow bottom-view imaging of the combustion chamber. The peak cylinder pressure (PCP) and the fuel mean effective pressure (Fuel MEP) for both the combustion modes are kept as 70 bar and 19 bar, respectively.
Technical Paper

Adaptive Cycle Engines: Results with 2nd Generation Combustion Model

2022-03-29
2022-01-0421
A more accurate combustion model, based on Fluent simulations including the effect of flame stretching and extinction, has been added to cycle and road simulations of an Adaptive Cycle Engine (ACE), where compressions and expansions do not follow a predefined sequence. Also, engine speed data from the Argonne Downloadable Dynamometer Database is used in the road simulations in lieu of the original constant-speed model. Results show a drop in predicted steady-state brake efficiency around 5% relative to the model using a standard Wiebe function for heat release rate, but peak bmep rises over 20%. Performance on road cycles is not greatly affected by the delayed combustion since the relationship between expansion mass and work is largely unchanged. Even with the refined model, ACE-equipped vehicles remain competitive with electric powertrains in pre-tax cost and overall emissions.
Technical Paper

Autoignition and Sooting Characteristics of Iso-Octane and Ethanol in an Optical Rapid Compression Machine

2022-03-29
2022-01-0419
With the introduction of EV technology into the light-duty vehicle market, the demand for gasoline in conventional spark ignition engines is projected to decline in the coming decades. Therefore, researchers have been investigating the use of gasoline and other light fuels in heavy-duty engine applications. In heavy-duty engines, the combustion mode will likely be non-premixed, mixing-controlled combustion, where the rate of combustion is determined by the fuel-air mixing process. This creates a range of mixture conditions inside the engine cylinder at every instance in time. The goal of this research is to experimentally quantify the sooting behaviors of light fuels under a range of compression ignition engine mixture conditions (i.e., a range of equivalence ratios).
Technical Paper

Two dimensional measurements of soot size and concentration in diesel ames by laser based optical methods

2022-03-29
2022-01-0416
Soot particle size, particle concentration and volume fraction were measured by laser based methods in optically dense, highly turbulent combusting diesel sprays under engine conditions. Experiments were done in the Chalmers high pressure, high temperature spray rig under isobaric conditions and combusting commercial diesel fuel. Laser Induced Incandescence (LII), Elastic Scattering and Light Extinction were combined quasi-simultaneously to quantify particle characteristics spatially resolved in the middle plane of a combusting spray at two instants after the start of combustion. The inuence that fuel injection pressure, gas temperature and gas pressure exert on particle size, particle concentration and volume fraction were studied. Probability density functions of particle size and two-dimensional images of particle diameter, particle concentration and volume fraction concerning instantaneous single-shot cases and average measurements are presented.
Technical Paper

Development of a Control-Oriented Cylinder Air-Charge Model for Gasoline Engines with Dual Independent Cam Phasing

2022-03-29
2022-01-0414
Cylinder air-charge is one of the most important parts of the torque control in a gasoline engine, due to the necessity to keep a stoichiometric air-fuel ratio, for the three-way catalyst to work efficiently. Throttle and phasing of the camshafts are actuators that have a big effect on the cylinder air-charge, this results in a cross-coupling between the actuators. One approach to handle the cross-coupling that occurs with multiple actuators is to use model predictive control (MPC), that handles the cross-coupling through the use of models and optimization. Models that support computation of gradients and hessians are desirable for use in MPC. To support the model design experimental data of cylinder pressure, from an inline four-cylinder engine with dual independent cam phasing, supported by gas exchange simulation, the effects from variable valve timing on the cylinder air-charge are investigated during the valve overlap period.
Technical Paper

Effect of Ethanol Reforming Gas Combined with EGR on Lean Combustion Characteristics of Direct Injection Gasoline Engine

2022-03-29
2022-01-0428
Ethanol reforming gas combined with EGR technology can not only improve thermal efficiency, but also reduce pollutant emission under lean combustion condition. In this paper, the effects of ethanol reforming gas and EGR on the combustion and emission characteristics of a direct injection gasoline engine under lean combustion are further discussed by means of experiment and simulation. The results find that compared with pure gasoline, the combustion speed of 20% hydrous ethanol is significantly faster, the combustion duration is shortened by 6 CA, the cylinder pressure and heat release rate are slightly increased, as well as the CO and HC emissions are reduced, based on the experiments. Moreover, the influence of ethanol reforming gas on the performance of a direct injection gasoline engine under rarefied combustion condition is investigated and analyzed by GT-Power and CONVERGE simulation.
Technical Paper

The Rotating Liner Engine under Medium Loads and Speeds. Fuel economy benefit exceeds 10%

2022-03-29
2022-01-0425
The Rotating Liner Engine (RLE) is a design concept where the cylinder liner of a Heavy Duty Diesel engine rotates by about 2-4 m/s surface speed in order to eliminate the piston ring and skirt boundary friction near top and bottom dead center. Based on testing results from our single cylinder RLE prototype (a converted four cylinder Cummins ISB 3.9 diesel) compared to a similar baseline, under idle conditions, the friction reduction is approximately 50 kPa in FMEP (friction mean effective pressure), which translates to about 40% for a complete engine. In this new set of experiments, we are comparing the RLE performance under load of up to about 7 bar IMEP (indicated mean effective pressure). It has been proven that the elimination of metallic contact between the compression rings and cylinder persists under up to 75 bar peak cylinder pressure and 1.5-2 m/s liner surface speed (283-383 rpm) for the 850-1150 rpm crankshaft speed.
Technical Paper

Benefits of Octane-On-Demand in an E10-Gasoline Engine Vehicle Using an On-Board Fuel Separator

2022-03-29
2022-01-0424
Knock in gasoline engines at higher loads is a significant constraint on torque and efficiency. The anti-knock property of a fuel is closely related to its research octane number (RON). Ethanol has superior RON compared to gasoline and thus has been commonly used to blend with gasoline in commercial fuels. As a result, an onboard Octane-on-demand (OOD) concept that separates commercial gasoline with ethanol content into high-octane fuel with high ethanol fraction and a lower octane remainder has been developed. It then uses both fuels in varying proportion to provide to the engine a fuel blend with just enough RON to meet the ever changing octane requirement that depends on driving pattern.
Technical Paper

Development of a Pre-Chamber Combustion System for the Magma xEV Engine

2022-03-29
2022-01-0422
The electrification of powertrains provides a critical opportunity to change the way that engines are designed and developed, allowing their efficiency to be increased and their cost reduced. This paper draws on ongoing Ricardo projects in the field of dedicated hybrid engines (DHEs). The Magma xEV combustion concept employs very high compression ratio, long stroke architecture, and advanced ignition and knock mitigation technologies, for DHEs requiring the highest efficiency. In the latest research project a pre-chamber combustion system (with both active and passive operation) has been applied to the Magma xEV engine, in order to enable the highest levels of charge dilution and further increase brake thermal efficiency. The research focussed on benefits of pre-chamber ignition as compared to spark ignition and corona discharge ignition. The benefits of charge dilution using lean operation and EGR as compared to stoichiometric are also presented.
Technical Paper

Spark Discharge Characteristics for varying Spark Plug Geometries and Gas Compositions

2022-03-29
2022-01-0437
Spark discharge properties were studied and characterized for varying gas compositions and spark plug geometries using a spark calorimeter and constant volume optical vessel. Two different 18mm natural gas engine spark plugs were used in the experiments. All measurements were recorded under quiescent conditions and with a spark gap of 0.30mm. The spark plug calorimeter was used for measuring thermal energy deposition to the gas for gas compositions of nitrogen, a stoichiometric mixture of nitrogen and methane, a stoichiometric mixture of nitrogen and methane, diluted with 30% carbon dioxide by volume, and for air. Other measurements of interest included breakdown voltage, electrical energy delivered to the spark gap, electrical-to-thermal energy conversion efficiency, and spark duration, for pressures up to 28 bar at 300K. The optical vessel was used for the combusting mixture of stoichiometric air and methane at pressures up to 28 bar.
Technical Paper

Pressure and Flow Field Effects on Arc Characteristics for a J-type Spark Plug

2022-03-29
2022-01-0436
Lean operation of spark ignition engines is a promising strategy for increasing thermal efficiency and minimize emissions. Variability on the other hand is one of the main shortcomings in these conditions. In this context, the present study looks at the interaction between the spark produced by a J-type plug and the surrounding fluid flow. A combined experimental and numerical approach was implemented so as to provide insight into the phenomena related to the ignition process. A sweep of cross-flow velocity of air was performed on a dedicated test rig that allowed accurate control of the volumetric flow and pressure. This last parameter was varied from ambient to 10bar, so as to investigate conditions closer to real-world engine applications. Optical diagnostics were applied for better characterization of the arc in different operative conditions. The spatial and temporal evolution of the arc was visualized with high speed camera to estimate the length, width and stretching.
X