bluuebunny/crossref_metadata_2025 huggingface dataset:
Material Compatibility of Elastomers and Plastics in Gasoline- Ethanol-Methanol Blends
Authors: Chakradhar Dr.  Maya , Ramadhas A S , Shanti Prakash , Justin P Raj , Arora Ajay , Maheshwari M
Published: April 2023

The current Indian biofuel policy focuses on the use of alcohol as a potential gasoline blending component to achieve a target of 20% alcohol in gasoline by 2025. The automotive vehicle fuel system uses a variety of metals and non-metals (elastomers and plastics). The fuel system is designed to run with a dedicated fuel, say gasoline or diesel. The use of alternative fuels, i.e., fuels that blend with straight gasoline or diesel, is increasing, and it is critical to understand the impact of these fuels on engine fuel system components. High octane fuels like ethanol and methanol are blended with gasoline to increase engine performance and reduce exhaust emissions, but the alcohols are hygroscopic and corrosive in nature. These fuels' permeation, swelling, and other effects cause changes in material properties. The test fuel is a gasoline-ethanol-methanol (GEM blend of A20 blend), which contains 5% ethanol, 15% methanol, and 80% gasoline. There is no data available on the use of A20 in the Indian context. Hence, there is a need to assess these materials for compatibility issues with the A20 fuel for the intended design life or if there is a modification in the fuel system components.

Material compatibility studies were carried out on materials used in components as per the guidelines given in SAE J 1748 for non-metal (elastomers and plastics) compatibility studies, which are specific for hydrocarbon fuels and their mixtures with oxygenated additives. The sample coupons are immersed in the test fuel at 55 °C in the oven for a period of 1008 hours for elastomers and 3024 hours for plastics. The material properties of elastomers (FKM, NBR, NBR-PVC, and ECO) and plastic material PA66 are evaluated before and after immersion to assess the impact of ageing on materials. The change in behaviour of materials—weight, volume, tensile strength, elongation, and hardness—is elaborately discussed. ECO (wet) and NBR (wet) show better performance in gasoline, and the rest of the elastomers show better or similar performance in all the properties with A20 and E10 fuels. ECO (wet) and NBR (wet) have shown better performance in gasoline, and the rest of the elastomers (FKM and NBR-PVC) show better or similar performance with E10 compared to A20. This study has revealed the material compatibility with the A20 fuel vis-a-vis gasoline/E10 fuels.
Vehicle Powertrain Simulation Accuracy for Various Drive Cycle Frequencies and Upsampling Techniques
Authors: O'Meally Franz , Holden Jacob , Gilleran Madeline
Published: April 2023

As connected and automated vehicle technologies emerge and proliferate, lower frequency vehicle trajectory data is becoming more widely available. In some cases, entire fleets are streaming position, speed, and telemetry at sample rates of less than 10 seconds. This presents opportunities to apply powertrain simulators such as the National Renewable Energy Laboratory’s Future Automotive Systems Technology Simulator to model how advanced powertrain technologies would perform in the real world. However, connected vehicle data tends to be available at lower temporal frequencies than the 1-10 Hz trajectories that have typically been used for powertrain simulation. Higher frequency data, typically used for simulation, is costly to collect and store and therefore is often limited in density and geography. This paper explores the suitability of lower frequency, high availability, connected vehicle data for detailed powertrain simulation. A large data set of 1 Hz trajectories is used to quantify the accuracy loss when simulating energy consumption for conventional, hybrid, and battery electric powertrains using less than 1 Hz data. Techniques to upsample lower frequency drive cycle data in order to increase accuracy are also explored. Median energy consumption errors when simulating energy consumption for a 1/10 Hz trajectory are found to be 3-6% when compared to 1 Hz trajectories. Applying upsampling and interpolation techniques are shown to reduce the simulation errors by roughly 50%. The findings in this work can guide connected vehicle data collection specifications and processing techniques applied when using collected data for powertrain simulation.
Development of Three-Way Catalysts with Enhanced Cold Performance
Authors: Tojo Takumi , Shirakawa Shogo , Nakahigashi Seiji , Hoshino Sho , Onozuka Takashi , Noguchi Takahiro , Aikawa Tomomasa
Published: April 2023

Global focus on CO2 reduction and environmental protection is increasing. To comply with stricter exhaust gas regulations and reduce real world emissions, it is becoming increasingly important to improve the performance of three-way catalysts. Therefore, highly efficient conversion of hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (NOx) is required. In general, the more active the precious metals used, the better the conversion performance. However, precious metals have supply risks, such as price fluctuation and the uneven distribution of production areas. Therefore, it is necessary to lower emissions while also lowering the amount of precious metals used. This paper focuses on how catalysts are used and describes the development of a new three-way catalyst for the purpose of strengthening cold conversion and decreasing the usage of precious metals.
Experimental and Numerical Investigation of a Particle Filter Technology for NG Heavy-Duty Engines
Authors: Di Maio Dario , Guido Chiara , Napolitano Pierpaolo , Beatrice Carlo , Golini Stefano
Published: April 2023

The forthcoming introduction of the EURO VII regulation requires urgent strategies and solutions for the reduction of sub-23 nm particle emissions. Although they have been historically considered as particulate matter-free, the high interest for Natural Gas (NG) Heavy-Duty engines in the transport sector, demands their compliance with the new proposed regulations.

In order to obtain high conversion of gas pollutants and a strong abatement of the emitted particles, the use of Particle Filters in NG aftertreatment (CPF) in conjunction with the Three-Way Catalyst (TWC) may represent an attractive and feasible solution.

Performances of a cordierite filter were explored through an extensive experimental campaign both in Steady-State conditions and during transient engine maneuvers that involved a whole analysis of the emitted particles in terms of number and mass.

This investigation assessed different emitted particle reduction efficiency, highlighting distinct levels between no-load (low idle phases) and load operating conditions.

The analysis was supported by the development of a specific 1D filtration model to evaluate the particles abatement. This model was also validated during a World Harmonized Transient Cycle (WHTC), proving to be a valuable tool for understanding filtration phenomena during critical phases of the cycle.

The tested filter technology showed high filtration efficiency with global levels approaching 90% over the whole cycle, without significant increase in backpressures and fuel consumption.

The performed analysis lays the foundation for the use of innovative and simplified filtration models to support the optimization process of this device in view of the next stringent regulations.
Analysis and Optimization of Metallic Based Substrates for After-Treatment System by Means of Full-Scale CFD Simulations and Experiments
Authors: Sartirana Andrea , Montenegro Gianluca , Della Torre Augusto , Onorati Angelo , Pace Lorenzo , Zaldua-Moreno Naroa
Published: April 2023

The tightening trend of regulations on the levels of admitted pollutant emissions has given a great spur to the research work in the field of combustion and after-treatment devices. Despite the improvements that can be applied to the development of the combustion process, pollutant emissions cannot be reduced to zero; for this reason, the aftertreatment system will become a key component in the path to achieving near-zero emission levels.

This study focuses on the numerical analysis and optimization of different metallic substrates, specifically developed for three-way catalyst (TWC) and Diesel oxidation catalyst (DOC) applications, to improve their thermal efficiency by reducing radial thermal losses through the outer mantle. The optimization process relies on computational fluid dynamics (CFD) simulations supported by experimental measurements to validate the numerical models carried out under uncoated conditions, where chemical reactions do not occur. Full-scale three-dimensional, multi-region models precisely describe the flow and temperature distributions allowing the evaluation of heat fluxes with the surrounding environment.

A test cycle was designed to replicate the typical warm-up of a catalyst followed by a drop in the gas temperature and then a drop in the mass flow, replicating the engine switch-off condition.

Different canning solutions and insulation strategies were considered at both numerical and experimental levels, and the results were compared. This allowed the validation of the numerical approach and identification of the best solution in terms of heat loss reduction and response time to heat up.
Challenges in PM Measurement at 1 mg/mile and Tunnel Background Correction
Authors: Yassine Mahmoud K.
Published: April 2023

The LEV IV FTP PM limit in the recently approved CARB ACC II regulations for passenger cars and light duty trucks will be 1 mg/mile starting in 2025. Gravimetric PM measurement at these levels is very challenging as the net mass of PM on the filter in full flow tunnel testing ranges between 8 to 32 micrograms depending on amount of dilution. This is approaching tunnel background levels which, in combination with filter handling, static charge removal and microbalance instability, compounds the uncertainty. One major source of the uncertainty at these low levels is the tunnel contamination resulting in high variability from test to test and cell to cell. This tunnel background is mostly HC artifact which cannot be easily controlled and can be significantly higher than the 5-μg CFR allowable correction limit in some test cells. Items that might affect the PM background include the type of testing being run on the tunnel prior to measuring the background such as OBD, cold and diesel testing. Quantifying the contribution of these artifacts and how they play into the overall uncertainty cannot be easily determined at this time. Regular conditioning and cleaning of the tunnel to keep the tunnel background below the 5-μg limit has shown to be crucial at these low levels. The process to drive contamination out and reduce the tunnel background below 5 μg will be described. A model is created to determine the range of net PM mass on the filter at 1 mg/mile with different CVS flowrates. The current process of tunnel background measurement and correction will be discussed. Countermeasures to reduce the uncertainty in PM measurement at 1 mg/mile PM level will be explored.
Experimental and Modeling Study on the Thermal Aging Impact on the Performance of the Natural Gas Three-Way Catalyst
Authors: Kim Mi-Young , Dadi Rama Krishna , Gong Jian , Kamasamudram Krishna
Published: April 2023

The prediction accuracy of a three-way catalyst (TWC) model is highly associated with the ability of the model to incorporate the reaction kinetics of the emission process as a lambda function. In this study, we investigated the O2 and H2 concentration profiles of TWC reactions and used them as critical inputs for the development of a global TWC model. We presented the experimental data and global kinetic model showing the impact of thermal degradation on the performance of the TWC. The performance metrics investigated in this study included CH4, NOx, and CO conversions under lean, rich, and dithering light-off conditions to determine the kinetics of oxidation reactions and reduction/reforming/water-gas shift reactions as a function of thermal aging. The O2 and H2 concentrations were measured using mass spectrometry to track the change in the oxidation state of the catalyst and to determine the mechanism of the reactions under these light-off conditions. The experimental data indicate that the NOx and CH4 conversions were higher under rich lambda conditions, thereby generating more NH3 than that observed under lean lambda conditions. Conversely, the NH3 formation was mitigated under the dithering conditions resulting from the recovery of redox properties. The measured O2 and H2 concentration profiles indicated that the conversion of CH4 was attributed to its reaction with O2 until O2 was fully consumed. Further, it was converted through a reforming reaction that produced H2 when O2 was depleted. Consequently, dithering conditions with a substantial amount of O2 showed a delayed onset of reforming chemistry and NH3 formation than those observed under rich conditions. The global kinetic model was developed based on the O2 and H2 data obtained under lean and rich conditions as inputs. The model predicted the NOx reduction chemistry in the presence of CO and H2, steam reforming, and the total oxidation of methane reasonably well. We also discussed an approach to improve the model predictions for the partial oxidation reaction of methane.
New 2.0 L Inline 4-Cylinder Gasoline Direct Injection Engine
Authors: Yamaguchi Ryo , Egawa Takeshi , Ushio Nobuhiro , Kasajima Yuya , Kondo Toshifumi , Ikeya Kenichiro
Published: April 2023

Honda has developed a new hybrid system targeting the C and D segments that aims for the latest environmental performance, high fuel economy, and enhanced acceleration feeling in driving. The new engine to be applied to this new hybrid system has been developed with the goal of expanding the high thermal efficiency range, realizing the latest environmental performance, and high quietness. The new engine has adopted the Atkinson cycle and cooled exhaust gas recirculation (EGR) carried over from the previous model [1], and employed an in-cylinder direct fuel injection system with fuel injection pressure of 35 MPa. The combustion chamber and ports have been newly designed to match the fuel system changes. By realizing high-speed combustion, the engine realized a high compression ratio with the mechanical compression ratio of 13.9. In addition, emission during engine start was suppressed by split injection and optimization of the injection timing to comply with the Super Ultra-Low Emission Vehicle (SULEV) regulations. The higher compression ratio and high-speed combustion increased the engine noise and vibration, and the high-pressure direct fuel injection system has generated larger operating noise than the conventional fuel injection system. Therefore, the crankshaft, cylinder block, oil pan, chain case, and other parts of the new engine have been newly designed to provide enhanced noise and vibration (NV) performance. Furthermore, the conventional acoustic insulators and Theta Fiber Cells (TFC) insulators that have sound absorption effects inside the engine room have been also redesigned. This achieved engine radiation noise equivalent to the previous model, and also contributed to enhancement of the vehicle quietness.
Experimental and Numerical Investigation of Hydrogen Injection and its Preliminary Impact on High Performance Engines Development
Authors: Paltrinieri Stefano , Olcuire Mattia , Calia Vito , Mortellaro Fabio , Medda Massimo , Gullino Fabrizio , Stapf Karl Georg , Geiler Jan , Jochmann Paul , Boee Matthias , Lippisch Michael , Wundling Claus
Published: April 2023

Under the proposed Green Deal program, the European Union will aim to achieve zero net greenhouse gas (GHG) emissions by 2050. The interim target is to reduce GHG by 55% by 2030. In the current debate concerning CO2-neutral powertrains, bio-fuels and e-fuels could play an immediate and practical role in reducing lifecycle engine emissions. Hydrogen however, is one of the few practical fuels that can result in near zero CO2 emissions at the tailpipe, which is the main focus of current legislation. Compared to gasoline, hydrogen presents a higher laminar flame speed, a wider range of flammability and higher auto-ignition temperatures, making it among the most attractive of fuels for future engines. As a challenge, hydrogen requires a very low ignition energy. This may imply an increased susceptibility to Low Speed Pre-Ignition (LSPI), surface ignition and back-fire phenomena. In order to exploit hydrogen’s potential, the injection system plays an extremely important role. This paper focuses on the experimental characterization of an H2 Direct Injection (DI) injector in order to provide a wide and robust dataset to be used in three dimensional Computational Fluid Dynamics (3D CFD) simulation correlations. For reasons of safety and practicality, Schlieren measurements are performed mainly using helium whereas the transposition to hydrogen is conducted via comparison of helium vs. hydrogen measurements as well as 3D CFD simulations. Injection simulations will help to set targets for new combustion chamber architectures and assess mixture preparation formation to support next generation injector development for a high performance oriented H2 engine.
Development of a High-Pressure Fuel Injection System for Use with Propane-DME
Authors: De Ojeda William , Wu Simon (Haibao)
Published: April 2023

Paper details the design approach and performance of a high-pressure common rail fuel injection system used with Propane-DME mixtures targeting high injection pressures on a light duty 2.2L inline-4 compression ignition engine. The study estimates the bulk modulus of elasticity based on the hardware geometry and operating pressures to assess the compressibility of Propane and DME across a range of pressures typical of the LD engine application. The compressibility factor ranges from 500 to 3000 bar, significantly lower than the theoretical values for the conditions tested. The high-pressure pump performance is optimized via the implementation of an inlet metering valve operated on a crank-angle open/close sequence to control pressure at the common rail. The application of a model-based controller and the use of high-speed sampling of rail pressure indicate that pressure at the rail can be attained with the pump metering valve, and without use of the pressure relieve valve present in the rail. Results show a significant reduction on pumping work parasitics and of fuel heating, on the order of 40°C, at typical working conditions with the proposed approach. Injector rates of injection with Propane-DME are very similar to those of Diesel. Paper compares bench data of rates of injection versus simulation predictions across operating pressures of 200 to 1000bar and from injection commands spanning 0.20 to 2.0ms. The accuracy of the model predictions are attributed in part by to the updated fuel compressibility modulus descriptions attained during the testing.
Analysis of Boosting Architectures for Hydrogen Internal Combustion Engines
Authors: Brin Jared , Waldron Thomas
Published: April 2023

Restrictive future CO2 emissions regulations are incentivizing evaluation of carbon-free fuels. This is particularly true in the difficult to electrify heavy commercial vehicle segment. The reemergence of hydrogen internal combustion (H2 ICE) for large displacement engines can both expedite hydrogen adoption and reduce total cost of ownership. This paper covers how the application of various boosting architectures can address challenges unique to H2 ICE. The research presented is derived from simulations conducted by AVL List GmbH and SuperTurbo Technologies on a 13L H2 ICE. The GT Power model was calibrated from dyno testing at AVL of an operational engine and then modified with different boosting systems. The primary H2 ICE challenge that is addressed is the requirement for the engine to maintain a lean-burn combustion strategy through transient operation in order to control NOx formation and minimize aftertreatment requirements. This high lambda requirement can create challenges for turbochargers when available turbine power is insufficient for the desired compressor power. The simulation includes both conventional turbochargers – VGT and 2-stage - and driven turbochargers – SuperTurbo, E-boost, and E-turbo. Each system was evaluated through the WHTC drive cycle and load step transients to show instantaneous and cumulative NOx, transient response capability and cycle efficiency. The goal of the research is to show the capability of different boosting systems related to the unique challenges for hydrogen combustion to maintain performance and drivability, while controlling engine out NOx emissions to minimize aftertreatment NOx conversion requirements.
Simulation and Measured Analysis of Dynamic Performance of Serpentine Belt Drive System
Authors: Chen Houchong , Wan Lixiang , Diao Qiangyou , Ding Quanyu , He Yanlin
Published: April 2023

The dynamic performance of the engine front end accessory drive system is one of the important factors affecting the NVH level of the vehicle and the service life of the system itself. Obtaining the dynamic response of the system is the basis for studying its dynamic performance. This paper takes a vehicle engine serpentine belt drive system as a study object, the dynamic simulation model of the drive system is established based on Simdrive 3D. Engine bench tests were conducted to test the dynamic response of the system under acceleration, single speed and start-stop conditions, including the angular displacement of the tensioner arm, the slip rate of the pulley and the belt transverse displacement. The simulation results and measured results are compared and analyzed, and it is judged whether the design of the drive system meets the requirements. Based on the simulation model, the influence of the tensioner damping ratio on the dynamic response of the serpentine belt drive system is studied. The analysis methods and conclusions in this paper have engineering practical significance for the design and development of the tensioner and the serpentine belt drive system.
Optimization Design and Performance Verification of the Second Generation Single Motor Plug-in Hybrid System (EDU) of SAIC Motor Vehicle Company
Authors: ge Hailong , Zhao Zhiguo
Published: April 2023

SEAT Department of SAIC Motor Vehicle Company starts innovatively applying the single motor and P2.5 configuration scheme from EDU G2(Electric Drive Unit Generation 2), which consists of six engine gears and four motor gears. EDU G2 is very compact and adaptable through the coupling design. Gear coupling make the engine and motor coordination limited, so as to the high efficiency zone of the engine and the high efficiency zone of the motor cannot match in some working conditions, which affect the performance of the vehicle. Therefore, SEAT developed the second generation of single-motor plug-in hybrid system EDU G2 Plus EDU G2(Electric Drive Unit Generation 2 Plus), which realized the decoupling design of 5 engine gears and 2 motor gears, so that the power output of engine and motor is freely. With excellent power and economic performance, the vehicle has been well received by customers. The article mainly describes the system design and development on the themes of motor performance improvement, system efficiency improvement and NVH optimization. SEAT takes the lead in adopting the hair-pin motor winding scheme, compared with the ordinary circular motor, the slot full rate of the Hairpin motor is increased by 20%~25%. The number of motor windings is increased from 2 layers to 5 layers, the maximum efficiency and comprehensive efficiency of the motor are significantly improved. Compared with the EDU G2, EDU G2 Plus has been optimized in some mechanical paths, including application of low roll resistance bearings, matching and selection of lubricating oil, optimization of cooling and lubrication system. In NVH performance , through motor body optimization and gear modification, the motor gear is reduced from 41 to 27 order, providing a more comfortable experience for the vehicle. The innovative scheme design of this paper provides a reference for the design and mass production of hybrid P2.5 configuration Plug-in Hybrid System.
Experimental Evaluation of VECTO Hybrid Electric Truck Simulations
Authors: Bitsanis Evangelos , Broekaert Stijn , Tansini Alessandro , Savvidis Dimitrios , Fontaras Georgios
Published: April 2023

In European Union (EU), new heavy-duty vehicles are simulated with the Vehicle Energy Consumption calculation TOol (VECTO) to certify their fuel consumption and CO2 emissions. VECTO will also be used to certify vehicles with hybrid-electric powertrains in all topological configurations from P0 to P4 parallel systems and series hybrids. A development version of VECTO able to simulate these configurations is already available and was used for this study.

The study team collected measurement data from a specific P2 hybrid lorry, instrumented with wheel torque sensors, current and voltage sensors, fuel flow sensor and a PEMS device. The vehicle was tested on the chassis dyno and on the road, and a representative model was created in VECTO.

The regional delivery certification cycle was simulated in VECTO in charge sustaining and full electric mode. The results show that the development version of VECTO is able to predict the fuel consumption of the vehicle under test in charge sustaining mode with a maximum error of 6.5% and the electrical energy consumption in full electric mode with an error of 2.5%. The VECTO Hybrid Controller was evaluated by comparing the measured and simulated decisions on utilising the available power sources (fuel/stored electric energy), regenerative braking, and gear shifting. Validation simulations with gear input were run for the regional delivery, showing significant improvements for the predicted fuel and electrical energy consumption error down to 2.5% and 1.5% respectively.
A Methodology to Design the Flow Field of PEM Fuel Cells
Authors: Corda Giuseppe , Cucurachi Antonio , Diana Martino , Fontanesi Stefano , D'Adamo Alessandro
Published: April 2023

Proton Exchange Fuel Cells (PEMFCs) are considered one of the most prominent technologies to decarbonize the transportation sector, with emphasis on long-haul/long-range trucks, off-highway, maritime and railway. The flow field of reactants is dictated by the layout of machined channels in the bipolar plates, and several established designs (e.g., parallel channels, single/multi-pass serpentine) coexist both in research and industry. In this context, the flow behavior at cathode embodies multiple complexities, namely an accurate control of the inlet/outlet humidity for optimal membrane hydration, pressure losses, water removal at high current density, and the limitation of laminar regime. However, a robust methodology is missing to compare and quantify such aspects among the candidate designs, resulting in a variety of configurations in use with no justification of the specific choice. This contrasts with the large operational differences, especially regarding the pressure loss/stoichiometric factor trade-off and in the outlet humidity level.

In this paper a simple thermodynamic model (0D) is presented to evaluate pressure losses, stoichiometric factors, channel length, and humidity level for typical flow fields. Based on distributed and concentrated pressure losses and on a water balance between the humidified air, the electrochemically produced water, and the electro-osmotic water flux, the model indicates the optimal flow field for a given active area. The methodology is validated using 3D-CFD models, assessing the predictive capability of the simplified 0D model, and it is applied to small/medium/large active area cases. The presented method introduces a model-based guideline for the design of PEMFCs flow fields, providing design indications to optimize the humid flow dynamics. The study shows the impact of flow field design on fuel cell operating conditions, providing guidelines for fuel cell engineering. In the limits of laminar flows, the parallel channel design demonstrated the lowest pressure drop (∆p ≃ 1 × 102 − 103Pa, more than one order of magnitude lower than other designs) and the best capability of saturated outlet flows (i.e., ideal membrane hydration) for current densities in the range 0.5 − 2.0 A/cm2, hence outperforming any other serpentine-type designs for medium-to-large active areas and with the focus on high current density operation.
Dynamic Simulation using ECMS Controller to Optimize the Fuel Economy of a Fuel Cell based HD Commercial Vehicle
Authors: Vankayala Sujeet Nagaraj , De Araujo Philippe , Zagun Michael , Okarmus Marcin , HOW Jake , Zeman Jonathan
Published: April 2023

Hydrogen-based fuel cell electric vehicles are a promising alternative to pure battery electric vehicles (BEV) in heavy-duty (HD) truck applications, due to lower weight penalty on the cargo mass, a higher range, and a lower refueling time. The overall drivetrain optimization (including battery and fuel cell sizing) requires an efficient and robust energy management concept, capable of exploiting the maximum system fuel saving potential, while considering critical component health metrics. In recent years, the Equivalent Consumption Minimization Strategy (ECMS) has demonstrated its capability to meet those requirements when applied to passenger car hybrid powertrains. In a traditional implementation, the ECMS-based control policy is typically calculated a-priori, based on steady state operating conditions. The solutions are then implemented as look up tables in the final dynamic model. In this paper, a novel model based online ECMS controller is implemented on a dynamic forward-facing simulation model of a fuel cell powered heavy-duty truck. The forward-facing model integrates a 0-D, lumped humidifier and 1-D stack model with a fuel cell compressor offering realistic response dynamics. The ECMS controller makes use of a kinematic backward-facing surrogate model of the drivetrain, including a polarization curve-based lookup of the fuel cell stack. In addition, to accurately account for driveline dynamics, suitable rate limiters are implemented in the surrogate model. The proposed modelling approach eliminates the need of a-priori ECMS calculations, and thus offers a significant workflow improvement. The resulting control strategy is applied and evaluated on two different regulatory cycles.
Design and Analysis on Separator-Ejector Integrated Device of Hydrogen Recirculation System in Proton Exchange Membrane Fuel Cell
Authors: Chen Yun , LUO Maji , Huang Yiyuan
Published: April 2023

Hydrogen recirculation system (HRS) is one of the main subsystems of proton exchange membrane fuel cell (PEMFC) system, and an HRS with high performance and low cost is essential to improve the fuel cell lifetime and efficiency. The ejector is becoming an effective alternative to the hydrogen circulation pump in the hydrogen recirculation system because of its small size, low cost and no parasitic power. However, the conventional ejector can only operate at the limited output power of the fuel cell. In order to improve this drawback, a hydrogen recirculation system with a separator-ejector integrated device is proposed. The hydrogen recirculation system based on the integrated device can make the space more compact, reduce the condensation effect of the piping, improve the fuel cell performance and reduce the cost. The design and integration method of the ejector and gas-water separator in this hydrogen recirculation system are introduced. The hydrodynamic model of the integrated structure is established and simulations are performed. A hydrogen recirculation system test platform is also built to experimentally analyze the hydrogen recirculation characteristics and verify the simulation model based on the experiments. Through the simulation study, the performance of the hydrogen recirculation system with the separated structure ejector is analyzed. The simulation results show that, compared with the conventional hydrogen recirculation system, the hydrogen recirculation system with the separator-ejector integrated device reduces the condensation and pressure drop in the tube, improves the hydrogen recirculation efficiency, and can cover a wider power output range of the PEMFC stack, from the range of 45kW to 100kW to the range of 30kW to 100kW, which can effectively improve the fuel cell performance and reduce the cost.
Development of Powertrain System and Battery for BEV
Authors: Nagai Hiroki , Kawamoto Naoya , Horiguchi Kotaro , Yoda Takehito , Hiyoshi Masatoshi , Yamamoto Masaya
Published: April 2023

Toyota has launched a new BEV which incorporates our newest evolutions in BEV powertrain systems and vehicle platform innovations. The new BEV uses newly developed large format battery cells, which, in addition to achieving our key performance and safety targets, also incorporates new technologies resulting in improved battery energy density and a reduction in battery deterioration. For the BEV battery cooling, to enhance safety, the cooling plate and the battery cells are separated by a chamber structure. The battery pack also incorporates a newly developed high resistance coolant with low conductivity. The new BEV improves system efficiency by leveraging some technologies that were originally developed for HEV and developing new systems. For example, radiant heating and a newly developed heat pump system improve EV driving range. This presentation will introduce our new battery technologies and discuss our new BEV system.
Current and Torque Harmonics Analysis of Dual Three-Phase Permanent-Magnet Synchronous Machines with Arbitrary Phase Shift Based on Model-in-the-Loop
Authors: Shi Bufan , Andert Jakob , Wang Haoran
Published: April 2023

Dual three-phase permanent magnet synchronous machines (DTP-PMSM) are becoming increasingly popular in automotive electric powertrains due to their reduced phase currents and fault tolerance. The unique advantages of specific phase shift angles (such as 0°, 30°, 60°, etc.) between dual three-phase windings have been extensively studied. In this paper, the current and torque harmonics induced by the inverter are analyzed and the corresponding harmonics suppression strategy are proposed for a DTP-PMSM with different phase shift angles. In addition, this paper analyzes the effect of the phase shift angle between the dual three-phase windings on the torque ripple and phase losses, and proposes a novel optimal phase shift angle 80°. First, a mathematical vector space decomposition (VSD) model for a DTP-PMSM with arbitrary phase shift angles is derived. Second, a theoretical derivation of the torque harmonics based on phase current and induced electromotive force harmonics is carried out, and the effects of current and rotor flux-induced electromotive force harmonics of (6k ± 1)thorders on torque ripple are obtained. For torque ripple suppression, the mapping of the phase current harmonics in VSD synchronous coordinate system with arbitrary phase shift angles is derived. Furthermore, a model-in-the-loop (MiL) simulation is set up using a mathematical model of an ideal electrical machine and a non-ideal 6-phase inverter model implemented in PLECS, and the VSD-based field-oriented control algorithm implemented in Matlab/Simulink. The simulation results for different phase shift angles show that the dq current, dqz current, dc-link current and torque harmonics vary periodically with the phase shift angle for (6k)th orders. In addition, the proposed 80° configuration has relatively lower losses and torque ripple after weighing both aspects over all the phase shifts. Finally, the harmonics suppression method is validated in the MiL.
Mechanical Design Considerations for Electric Vehicle Power Electronics
Authors: Abu-Zama Dawud , Badawi Ranya , Teimor Mehrdad , Suciu Ioan
Published: April 2023

Designing power electronics to operate in harsh vehicle environments while meeting packaging requirements such as mass, volume, and power density, creates several challenges for their mechanical design. In this work, we concentrate on the power inverter module (PIM) which converts high voltage (HV) DC voltage power from the HV battery to AC power to drive the motor. The PIM main components are the power module, gate drive and the bulk capacitor. The sizing and selection of the bulk capacitor and power module depend on performance criteria and drive profiles in addition to operating temperatures. In this work, we share the main challenges of packaging components within the inverter. We then discuss best practices to ensure a robust mechanical design which meets inverter durability and reliability targets for an electric vehicle application. The main challenges discussed are bulk capacitor thermals, sealing, and Silicon Carbide (SiC) packaging. The bulk capacitor offers a low impedance path to current ripple generated and reduces the leakage of the power module. Current ripple causes significant heat rise, so proper thermal management is key to ensure lifetime targets. Sealing the inverter enclosure and coolant channel prove to be one of the greatest challenges in packaging. The final topic discussed is SiC packaging and the different methods used to design a power module containing SiC dies such as sintering for die-attach. Power module substrate cooling is also addressed.
A One-Way Coupled Modeling Method to Simulate Battery Pack Thermal Runaway Initiated by an External Impact
Authors: Hoffmeyer Matthew , Shah Bansal , Surampudi Bapiraju
Published: April 2023

There is an ongoing proliferation of electric and electrified vehicles as manufacturers seek to reduce their carbon footprint and meet the carbon reduction targets mandated by governments around the world. An ongoing challenge in electric vehicle design is the efficient and safe design of battery packs. There are significant safety challenges for lithium battery packs relating to thermal runaway, which can be initiated through overheating and internal short from defects or external damage. This work proposes a robust method to couple the mechanical damage in a battery module calculated from a dynamic model with a thermal model of the battery that includes heating from electro-chemical sources as well as Arrhenius reactions from the battery cells. The authors identify the main sources of thermal runaway initiation and propagation in an impact scenario simulating a vehicle collision. The modeling approach was developed and validated using test data. This method can be used to design and engineer reliable thermal runaway mitigation prior to building and testing large prototype battery packs.
Optimization of Air Extraction Path for Superior Customer Comfort While Door Closing Event of a Sports Utility Vehicle (SUV)
Authors: Unadkat Siddharth Bhupendra , Pandurangan Venugopal , Selvan Veera
Published: April 2023

The passenger car segment has been extremely competitive and automotive OEMs are thriving to provide superior customer experience. Door closing is an event that requires slamming of the door with a certain velocity to get the door latched. A good latching provides that thud sound and assurance of the door getting closed for an SUV. While the door is closed, it pushes the volume of air inside the cabin. As the amount of air moved in is proportionate to the size of the door it becomes more critical for the SUV segment of vehicles to ensure the air extraction path is efficient. Else, steep pressure rise inside the cabin causes severe discomfort to the passengers sitting inside the vehicle. Current work focused on the process of simulation of cabin pressure while door closing, implementing changes based on results and validating with test results. Test results are in close correlation with simulation predictions. Also, it emphasizes that body panel changes made to improve the airflow path are extremely necessary. The outcome has been excellent, rated by jury members, and the proposed changes have been realized for production.
Invest in Adhesive Dispensing to Reduce Design, Capital, and Operational Costs
Authors: Lee Michael J.
Published: April 2023

Leveraging the increased use of Structural Adhesive in Automotive Body Structure Design has many proven benefits. It is a well-known method used to enable weight reduction in vehicle design and can also drive more efficient structural performance during dynamic safety events. This is increasingly important as vehicle safety standards increase, and as vehicle mass increases due to electrification. Often the benefits of adhesive use are not fully optimized due to unnecessary design redundancies or process driven redundancies. Design redundancy; using both welds and adhesive, is often included because government safety regulations require very robust validation of structures, and when combined with the use of Process Quality Control methods such as Batch Control and Sampling, can infer confidence in the design and process, but don’t ensure it. This paper proposes a different and unique approach to Product Design and Process Control, which will create an opportunity to eliminate redundancy, and can unlock significant design and process operational and capital cost savings. To truly ensure Quality Control of the structural adhesive bead, real-time verification along with Adaptive Process Control (APC) of the dispensing process is required. With fully guaranteed quality, design redundancies can be eliminated, and the design and processes can be concurrently optimized. The commitment to APC technology must happen very early in the Program, to enable an early focused design optimization effort to minimize the number of spot welds while maximizing structural adhesive use. Too often, the decision to invest in enabling technology in the manufacturing process, is made without considering design optimization. Also, the high-level decisions that can enable capital investment and operating cost savings are often caught in complex organizational finance processes. APC technology and equipment is purchased by Manufacturing entities, but without the confirmed product variable cost savings being identified early enough, the capital expenses won’t be justified or approved. This paper seeks to unravel that Catch-22 issue. Very few vehicle manufacturers are taking this pro-active step to commit to the use of APC technology in dispensing early in a vehicle program. Most OEM manufacturers design products in a very serial development process, design, tool, produce; with limited synergy due to the very rapid design cycle. They are missing a readily available opportunity to eliminate sub-optimization, added cost, added labor, and redundancy. To accomplish full efficiency and optimization, requires very close and early collaboration between the product design engineers and manufacturing engineers, and cross-organizational agreement.
Electric Motorcycle Acceleration, Braking, and Regenerative Coast-Down Deceleration Testing and Analysis
Authors: Phan Chris , Meza Buendia Saul A. , Nguyen Benjamin Mai , Fatzinger Edward , Landerville Jon
Published: April 2023

Three fully electric motorcycles were tested and analyzed for acceleration, braking, and regenerative coast-down deceleration. A Zero DSR, BMW C-Evolution, and a Harley-Davidson LiveWire underwent each of the following test series. The first test series consisted of accelerating the electric motorcycles from a stop. For the second test series, the motorcycles were decelerated by using three different brake applications: front and rear brake application, front-only brake application, and rear-only brake application. For the third test series, regenerative coast-down deceleration was tested at different ride mode configurations. Regenerative braking systems are designed to convert the vehicles’ kinetic energy into electrical potential energy during the vehicles’ coast-down phase, resulting in a moderate deceleration. In addition to testing the vehicles’ deceleration during its’ regenerative coast-down phase, brake light activation delay relative to throttle roll-off was analyzed. All motorcycles were tested on factory available ride mode configurations (Zero: Eco and Sport, BMW: Eco Pro, Dynamic, Road, and Sail, Harley-Davidson: Range, Street, Rain, and Sport). Each motorcycle was instrumented with a VBOX 3i with NTRIP (Networked Transport of RTCM via Internet Protocol) RTK (Real-time kinematic positioning) accuracy to measure and document vehicle speed.

The electric motorcycles tested produced a 0 – 60 mph acceleration range of 0.29 – 0.77 g. Average acceleration for all tested motorcycles and all modes available was calculated to be 0.53 g. For the braking test series including front and rear brake application, front-only, and rear-only brake application, the electric motorcycles braked at a deceleration range of 0.30 – 0.86 g. Average brake deceleration for all tested motorcycles and available ride modes was calculated to be 0.59 g. During the regenerative coast-down deceleration test series, the electric motorcycles decelerated at a range of 0.10 – 0.33 g. Average regenerative braking of all tested electric motorcycles and available modes was calculated to be 0.15 g. Brake light activation delay relative to accelerator throttle roll-off ranged from 0.05 – 1.1 sec. Average brake light activation delay was calculated to be 0.31 seconds relative to throttle roll-off. The results of this study will provide insight for accident reconstructionist to characterize acceleration, braking, and regenerative coast-down deceleration capabilities for the following electric motorcycles: Zero DSR, BMW C-Evolution, and Harley-Davidson LiveWire.
Dynamic Switch Control of Steering Modes for 4WID-4WIS Electric Vehicle Based on MOEA/D Optimization
Authors: Qiao Yiran , Chen Xinbo , Li Ran
Published: April 2023

To overcome the shortcoming that vehicles with multiple steering modes need to switch steering modes at parking or very low speeds, a dynamic switch method of steering modes based on MOEA/D (Multi-objective Evolutionary Algorithm Based on Decomposition) was proposed for 4WID-4WIS (Four Wheel Independent Drive-Four Wheel Independent Steering) electric vehicle, considering the smoothness of dynamic switch, the lateral stability of the vehicle and the energy economy of tires. First of all, the vehicle model of 4WID-4WIS was established, and steering modes were introduced and analyzed. Secondly, the conditions for the dynamic switch of steering modes were designed with the goal of stability and safety. According to different constraints, the control strategy was formulated to obtain the target angle of the active wheels. Then aiming at the smoothness of the dynamic switch, the active wheel angle trajectory was constructed based on the B-spline theory. And the MOEA/D algorithm was used to carry out multi-objective optimization of the trajectory to obtain the Pareto optimal solution set. The optimal active wheel angle switch trajectory was decided by TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) decision-making model. Last but not least, in the Simulink-CarSim co-simulation environment, the results of wheel angle, yaw rate, and sideslip angle were compared under different control strategies. The proposed control strategy achieved smoother dynamic switch of steering modes and ensured better handling stability, thus verifying the effectiveness of the strategy.