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Technical Paper

Design of a Human-centric Auto-Climate Control System for Electric Vehicles

2022-03-29
2022-01-0194
As the global automotive industry makes a critical transition from the traditional ICEVs (Internal Combustion Engine Vehicles) to EVs (Electric Vehicles), it faces two conflicting technological challenges: 1) range degradation in cold weather conditions and 2) reducing time to thermal comfort in winter driving in absence of waste heat from the IC engine. Next to the EV drivetrain, the HVAC system is the highest consumer of electric power in the vehicle. A recent study conducted by AAA showed that interior heating can reduce the EV range by up to 41% at 20 deg. F (https://apnews.com/article/04029bd1e0a94cd59ff9540a398c12d1). Also, in 2018, the average urban commute in the United States was roughly 27 minutes (https://www.washingtonpost.com/business/2019/10/07/nine-days-road-average-commute-time-reached-new-record-last-year/). So, it is necessary to get the driver to a thermally comfortable state as quickly as possible to make EVs attractive to consumers.
Technical Paper

Demonstrating UVC LED Inside Automobile HVAC Chambers for Clean Cabin Air and Airborne Transmission Risk Reduction

2022-03-29
2022-01-0197
The COVID-19 pandemic affected mobility in many ways- from changing business models of moving passenger to delivering packages and food, developing cleaning protocols for interiors and increasing the awareness of consumers to the hidden dangers of pathogens and viruses in an enclosed space. A trend towards healthy cars is believed to remain after the current pandemic and has led to the emergence of new safety features, from CO2 gas sensors, to antimicrobial fabrics, and enhanced air purifiers. While air purifiers trap contaminants using cartridge filters, they are not particularly efficient at removing viral particles and create large pressure drops, which must be compensated with larger fans, increasing noise and power consumption, both of which are not optimal for vehicle HVAC systems. However, air purifiers act as a pressure head, which limits their utility. UVC was not previously an option because mercury lamps pose their own electrical and chemical hazards.
Technical Paper

Numerical Investigation on the Internal Flow Field of Electronic Expansion Valve as the Throttle Element

2022-03-29
2022-01-0318
As one of the key components of the heat pump system, the electronic expansion valve mainly plays the role of throttling and reducing pressure in the heat pump system. The refrigerant flowing through the orifice will produce complex phase change. It is of great significance to study the internal flow field by means of CFD calculations. Firstly, a three-dimensional fluid model is established and the mesh is divided. Secondly, the phase change model is selected, the material is defined and the boundary conditions are determined. According to the principle of the fluid passing through thin-walled small holes, the flow characteristics of electronic expansion valve are theoretically analyzed. Then the flow characteristics of expansion valve are numerically calculated, and a bench for testing mass flow rate of the expansion valve is built. Then the theoretical value, CFD value and experimental value are compared to verify the correctness of the established three-dimensional fluid model.
Technical Paper

Design and Optimization of an Electric Car Chassis and Body using Structural Analysis and CFD

2022-03-29
2022-01-0292
The transition from traditional gasoline-powered automobiles to electric vehicles (EVs) has taken time, two major challenges of engine- powered vehicles are greenhouse gas emissions and fuel economy. Electric cars require less maintenance. A lot of money can be saved while also helping the environment. In today's world, working with lightweight materials have emerged as a key area for improvement in the automotive industry. The most efficient method for increasing power output is to reduce the weight of vehicle components. Composite materials have benefited greatly from research and development because they are stronger, more recyclable, and easier to integrate into vehicles. The primary goal of this research is to design the body and chassis frame of a two-seater electric car.
Technical Paper

Numerical Assessment of Tribological Performance of Different Llow Viscosity Engine Oils in a 4-Stroke CI Light-Duty ICE

2022-03-29
2022-01-0321
Decreasing fuel consumption in Internal Combustion Engines (ICE) is a key target for engine developers in order to achieve the CO2 emissions limits during a standard cycle. In this context, reduction of engine friction can help meet those targets. The use of Low Viscosity Engine Oils (LVEOs), which is currently one of the avenues to achieve such reductions, is studied in this manuscript through a validated numerical simulation model that predicts the friction of the engine’s piston-cylinder unit, journal bearings and camshaft. These frictional power losses are obtained for four different lubricant formulations which differ in their viscosity grades and design. Results show a maximum friction savings of up to 6% depending on the engine operating condition, where the major reductions come from hydrodynamic-dominated components such as journal bearings, despite an increase in friction in boundary-dominated components such as the piston-ring assembly.
Technical Paper

Investigation of Heat Transfer Characteristics of Heavy-Duty Spark Ignition Natural Gas Engines Using Machine Learning

2022-03-29
2022-01-0473
Machine learning algorithms are effective tools to reduce the number of engine dynamometer tests during internal combustion engine development and/or optimization. This paper provides a case study of using such a statistical algorithm to characterize the heat transfer from the combustion chamber to the environment during combustion and during the entire engine cycle. The data for building the machine learning model came from a single cylinder compression ignition engine (13.3 compression ratio) that was converted to natural-gas port fuel injection spark-ignition operation. Engine dynamometer tests investigated several spark timings, equivalence ratios, and engine speeds, which were also used as model inputs. While building the model it was found that adding the intake pressure as another model input improved model efficiency.
Technical Paper

A quick method to evaluate fuel chemistry on vehicle particulate emissions

2022-03-29
2022-01-0489
Fuel chemistry plays a crucial role in the continued reduction of particulate emission (PE) and cleaner air quality while using internal combustion engines (ICE). Over the past ten years, there has been great improvements in the measurements of particulate formation indices. Examples of these indices would be the Honda Particulate Matter Index (PMI) equation and the General Motors Particulate Evaluation Index (PEI), among others. Even though there have been improvements in particulate index (PI) measurement tools, the method analysis within these tools are still very time-consuming. These methods can include the use of chromatography separation techniques such as detailed hydrocarbon analysis (DHA), which have become very popular in the petrochemical industry. A review of historical PI methods will be discussed, along with a PE comparison to a less time-consuming simulated distillation method analysis.
Technical Paper

Gasoline Direct Injector Deposits: Impacts of Fouling Mechanism on Composition and Performance

2022-03-29
2022-01-0488
Gasoline Direct-Injection Spark-Ignition (DISI) injector performance is a key focus in the automotive industry as the vehicle parc transitions from Port Fuel Injected (PFI) to DISI engine technology. DISI injector deposits, which may impact the fuel delivery process in the engine, seem to accumulate over longer time periods and greater vehicle mileages than traditional combustion chamber deposits (CCD). These higher mileages and longer timeframes make the evaluation of these deposits in a laboratory setting more challenging due to the extended test durations necessary. The need to generate injector tip deposits for research purposes begs the questions, can an artificial fouling agent to speed deposit accumulation be used, and does this result in deposits similar to those formed naturally? Field testing was used to develop high-mileage injectors from DISI vehicles.
Technical Paper

Laser-Based In-Exhaust Gas Sensor for On-Road Vehicles

2022-03-29
2022-01-0535
Indrio Technologies has developed a novel on-board sensor, named Ignis, for detecting oxides of nitrogen (NOx) and ammonia (NH3) in diesel exhaust streams with sensitivities and molecular specificity unmet by existing technologies. This is a key technological need for diesel engine manufacturers, who face difficulty in precisely controlling their exhaust aftertreatment systems due to the lack of widely deployable sensors capable of differentiating between NOx, NH3 and other species in the exhaust stream. The successful incorporation of the proposed sensor can result in greater fuel efficiency improvements while matching new stringent 2027 California and 2030 EPA NOx emissions standards. Once the product has reached deep market penetration, the fleet-wide fuel economy improvements and NOx emissions reductions enabled by this product will lead to reduced carbon emissions and healthier air with lower amounts of NOx-induced smog, ground-level ozone, and acid rain.
Technical Paper

Impact of Chemical Contaminants on Stoichiometric Natural Gas Engine Three-Way Catalysts with high mileage history

2022-03-29
2022-01-0542
Stoichiometric natural gas engines with Three-way catalysts (TWCs) more efficiently reduce NOx and CH4 emissions compared to lean burn natural gas engines. Even though TWCs are well known, there is a need for deeper understanding beyond hydrothermal aging (HTA) to explain the real-world performance and aging behaviors. In this investigation, we characterized the real-world TWC to specifically identify the contribution of chemical aging to overall performance. The sulfur (S) species was evenly distributed throughout the whole catalyst volume, whereas phosphorous (P) contamination was mainly observed at the inlet section of the TWC and its concentration sharply declined along the axial length. Sulfur amount on the catalyst surface is quantified by TPD and ICP. Performance is measured pre and post sulfur removal on TWC to isolate the contribution of degradation due to HTA+P and that due to S.
Technical Paper

A Review of Current Understanding of the Underlying Physics Governing the Interaction, Ignition and Combustion Dynamics of Multiple-injections in Diesel Engines

2022-03-29
2022-01-0445
This work is intended to be a comprehensive technical review of existing literature and a synthesis of current understanding of the governing physics behind the interaction of multiple fuel injectio ns, ignition and combustion behavior of multiple-injections in diesel engines. Multiple-injection is a widely adopted operating strategy applied in modern compression-ignition engines, which involves various combinations of small pre-injections and post-injections of fuel before and after the main injection and splitting the main injection into multiple smaller injections. This strategy has been conclusively shown to improve fuel economy in diesel engines while achieving simultaneous NOx, soot, and combustion noise reduction in addition to a reduction in the emissions of unburned hydrocarbons and CO by preventing fuel wetting and flame quenching at the piston wall.
Technical Paper

Development and validation of an EHN mechanism for fundamental and applied chemistry studies

2022-03-29
2022-01-0455
Autoignition enhancing additives have been used for years to enhance the ignition quality of diesel fuel, with 2-ethylexyl nitrate (EHN) being the most common additive. EHN also enhances the autoignition reactivity of gasoline, which has advantages for some low-temperature combustion techniques, such as Sandia’s Low-Temperature Gasoline Combustion (LTGC) with Additive-Mixing Fuel Injection (AMFI). LTGC-AMFI is a new high-efficiency and low-emissions engine combustion process based on supplying a small, variable amount of EHN into the fuel for better engine operation and control. However, the mechanism by which EHN interacts with the fuel remains unclear. In this work, a chemical-kinetic mechanism for EHN was developed and implemented in a detailed mechanism for gasoline fuels. The combined mechanism was validated against shock-tube experiments with EHN-doped n-heptane and HCCI engine data for EHN-doped regular E10 gasoline. Simulations showed a very good match with experiments.
Technical Paper

Experimental Evaluation of Methane-Hydrogen Mixtures for Enabling Stable Lean Combustion in Spark-Ignition Engines for Automotive Applications

2022-03-29
2022-01-0471
Economy decarbonization will be one of the main goals for the following years. Research efforts are being focused on reducing carbon-based emissions, by increasing the efficiency of the transport power plants while developing new fuel production methods that reduce the environmental footprint of the refinement process. Consequently, the depletion of conventional fuels derived from petroleum with high carbon content, such as gasoline and diesel, motivated the development of propulsive alternatives for the automotive sector. In this paradigm, methane (CH4) fuel appears as a mid-term solution due to its low carbon content, if compared with traditional fuels, and the low CO2 emissions during its production from renewable sources. However, the intrinsic properties of methane compromise the combustion process, subsequently increasing the emission of CO2.
Technical Paper

Uncertainty Quantification of Wet Clutch Actuator Behaviors in P2 Hybrid Engine Restart Process

2022-03-29
2022-01-0652
Advanced features in automotive systems often necessitate the management of complex interactions between system components. To accomplish this task, closed-loop feedback is commonly used for effective real-time controls. Alternatively, open-loop schemes with adaptive parameters can be applied when real-time feedback is infeasible. Although these strategies possess certain levels of robustness, their performance can deteriorate in the presence of significant uncertainties, resulting in undesirable system behaviors. This limitation is often further amplified in systems with complex nonlinear dynamics. A hydro-mechanical clutch actuator is among those systems whose behaviors are highly sensitive to variations in sub-component characteristics and operating environment. In a P2 hybrid system, a wet clutch is utilized for cranking the engine during EV-HEV mode switching.
Technical Paper

Modeling of regeneration dynamics in gasoline particulate filters and sensitivity analysis of numerical solutions

2022-03-29
2022-01-0556
Gasoline Direct-Injection (GDI) engine technology improves vehicle fuel economy toward future targets and simultaneously decreases CO2 emissions. The main drawback of this technology is the increased emission of particulates (when compared to their indirect injection-based technology counterpart). Thus, aftertreatment devices such as Gasoline Particulate Filters (GPFs) are today considered the most promising and practically adoptable solution to limit PM/PN out of GDI exhaust. The particulate filter traps soot particles resulting from fuel combustion and prevents their release into the atmosphere. Soot oxidation (also known as regeneration) is required at regular intervals to clean the filter, maintain a consistent soot trapping efficiency, and avoid the formation of soot plugs in the GPF channel.
Technical Paper

A Study on the Impact of Driving in Charge Mode on Well-To-Wheels Greenhouse Gas Emissions of Plug-in Hybrid Electric Vehicles

2022-03-29
2022-01-0668
Plug-in hybrid electric vehicles (PHEVs) combine some of the attractive traits of both fully electric vehicles (EVs) and non-plug-in hybrid vehicles (HVs). EV traits shared by PHEVs include the capability to charge the battery via electricity from the grid while the vehicle is parked and the ability to drive an appreciable distance without having to turn the engine on, in what is known as charge depletion mode. HV traits shared by PHEVs include the ability to use the engine to maintain the state of charge (SOC) of the batteries within certain limits, in what is known as charge sustaining mode. Charge sustaining mode allows a PHEV to not be limited by battery charging time when undergoing long distance travel (unlike EVs), but comes at the trade-off in that gas (or more generally, any fuel) needs to be used, similar to an HV.
Technical Paper

Analytical modeling and multi-objective optimization of the articulated vehicle steering system

2022-03-29
2022-01-0879
Articulated steering system is widely used in engineering vehicles due to its high mobility and low steering radius. The design parameters have a vital impact on the selection of the steering system assemblies, such as the operation stroke, pressure, and force of the hydraulic cylinders during the steering process, which will affect the system weight. The energy consumption is also relevant to the geometry parameters. According to the kinetic analysis of the steering system and dynamic analysis of the steering process, the kinetic model of an engineering vehicle steering system is established, and the power needed to boost it is calculated and validated by the field test result. The influence of the factors is analyzed based on this model. To lower the system weight and needed pressure, the multi-objective particle swarm optimization method is initiated to optimize the geometry parameter of the articulated steering system.
Technical Paper

Experimental and Numerical Investigation of Rim Aerodynamics

2022-03-29
2022-01-0891
The automotive industry is facing new emission regulations, changing customer preferences and technology disruptions. All have in common, that external aerodynamics plays a crucial role to achieve emission limits, reduce fuel consumption and extend electric driving range. Probably the most challenging components in terms of numerical aerodynamic drag prediction are the wheels. Their contribution to the overall pressure distribution is significant, and the flow topology around the wheels is extremely complicated. Furthermore, deltas between different rim designs can be very small, normally in the range of only a few drag counts. Therefore, highly accurate numerical methods are needed to predict rim rankings and deltas. This paper presents experimental and numerical results of four different production rim designs, mounted to a modified production car.
Technical Paper

Further Analysis of the Blockage Phenomenon During the Testing of Bluff Automotive Bodies in Closed Wall Wind Tunnels

2022-03-29
2022-01-0887
The difficulties of testing a bluff automotive body of sufficient scale to match the on-road vehicle Reynolds number in a closed wall wind tunnel has led to many approaches being taken to adjust the resulting data for the inherent interference effects. But it has been impractical if not impossible to experimentally analyze the effects that are actually occurring on and around the vehicle when these blockage interferences are taking place. The present study is an extension of earlier work by the author and similarly to that study uses the CFD analysis of several bodies of differing configurations to examine the interference phenomena in solid wall wind tunnels and the effects that they have on the pressures, forces and force increments experienced by the vehicle model. This is accomplished by executing a series of CFD configurations with varying sized of the cross section from 0.2% to 13% blockage enabling an approximation of free air conditions as a reference.
Technical Paper

Ultimate Breakage Load Calculation Method of Cold Gas Inflator Burst Disk

2022-03-29
2022-01-0764
For cold gas Inflator, high refinement of ultimate load forecast is one key of Inflator development. At beginning, two methods based on implicit algorithm, Zero Curvature method and RIKS method were used for burst disk hydro-burst test ultimate pressure load calculation. After considering the effect of bursting disk stamping process, comparing with results of real test, the refinement of the two methods were above 97% both. Studying the corresponding relations between displacement and stress matrix of the center point of burst disk by RISK method. It was found that under ultimate load, the third principal stress vs. displacement curve of the central node shown extreme point, and load step of the point was corresponding the one of maximum pressure load. This shown that after reaching the ultimate load, the center of the bursting disc lost stability in the direction of thickness.
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