bluuebunny/crossref_metadata_2025 huggingface dataset:
Laminar Burning Velocities of Diluted Stoichiometric Hydrogen/Air Mixtures
Authors: Barain Ahmed , Trombley Grace , Duva Berk Can , Toulson Elisa
Published: April 2023

Since its implementation, exhaust gas recirculation has proven to be a reliable technique to control NOx emissions by lowering combustion temperature. Dilution with exhaust gas recirculation, whether in internal combustion engines or sequential-staged gas turbine combustors, affects flame reactivity and stability, which are related to the heat release rate and engine power. Another way to control emissions is to use hydrogen as a carbon-free alternative fuel, which is considered a milestone in the energy-decarbonization journey. However, the high reactivity of hydrogen is one of its hurdles and understanding this effect on laminar burning velocity is important. Flame propagation and burning velocity control the mixture reactivity and exothermicity and are related to abnormal combustion phenomena, such as flashback and knock. Therefore, understanding the effect of exhaust gas addition on the laminar burning velocity of hydrogen/air mixtures is imperative for engine design. In this work, a constant volume combustion chamber was used to observe the laminar burning velocity of stoichiometric hydrogen/air mixtures diluted with combustion products at 1 bar and 423K. Actual combustion products (35 % H2O + 65 % N2, by mole) were used for dilution at rates of 0-50%. The burned gas Markstein length was calculated for all mixtures. Experimental results of the laminar burning velocities for all mixtures were compared with kinetic modeling results. These measurements showed the monotonic reduction of reactivity and the laminar burning velocity with dilution. The reduced burning rates at higher dilution were reflected on the pressure gradient inside the vessel. Markstein length values decreased with dilution, meaning that flame instabilities increased with dilution.
Real Time Observations of Water Entering and Leaving Internal Combustion Engine Oil, Over Both Standard Engine, ICE and Plug-in Hybrid, PHEV Dynamic Drive-Cycles
Authors: Butcher Richard , Bradley Nathan , Powell Timothy
Published: April 2023

Due to the global drive for carbon neutrality, passenger vehicle gasoline engines are transitioning to higher levels of electrification, such as hybrid electric vehicles and plug-in hybrid electric vehicles, HEVs and PHEVs. Compared with conventional internal combustion, ICE only operation, the combustion engine in a HEV or PHEV typically operates for shorter periods. In turn the engine coolant and lubricant temperatures are often lower. Such cooler engine running is particularly noticeable for a variety of conditions including short journeys in charge-sustaining mode, urban motoring, a journey length towards the end of the electric range, at cold ambient temperatures, or a combination of these conditions. All C-type piston rings allow limited combustion gases to escape through the ring end-gap. Though the crankcase ventilation system will remove the blowby gases into the engine air inlet system, the crankcase blowby gases are able to mix with the lubricating oil as it returns to the sump. However, the ability of fuel and water in the blowby to evaporate from the engine oil is influenced by temperature. This paper presents sensor data showing, in real time, how this water exists in the blowby gases within the airspace of the engine crankcase. With direct reading sensors it shows how the water level in the oil increases and decreases in key areas within a running engine over the WLTC drive-cycle. Data for a standard internal combustion engine is compared with a plug-in hybrid cycle, in charge-sustaining mode. A range of lubricant formulations are tested. A comparison is established, between the observed water content sensor data over a single cycle with the widely known Karl Fischer titration method over a longer run test. Aspects of Karl Fischer titration sample practical preparation are discussed, these are required for a used oil sample with high water content.
Energy Modeling of Deceleration Strategies for Electric Vehicles
Authors: Hom William , Nelson Douglas
Published: April 2023

Rapid adoption of battery electric vehicles means improving the energy consumption and energy efficiency of these new vehicles is a top priority. One method of accomplishing this is regenerative braking, which converts kinetic energy to electrical energy stored in the battery pack while the vehicle is decelerating. Coasting is an alternative strategy that minimizes energy consumption by decelerating the vehicle using only road load. A battery electric vehicle model is refined to assess regenerative braking, coasting, and other deceleration strategies. A road load model based on public test data calculates tractive effort requirements based on speed and acceleration. Bidirectional Willans lines are the basis of a powertrain model simulating battery energy consumption. Vehicle tractive and powertrain power are modeled backward from prescribed linear velocity curves, and the coasting trajectory is forward modeled given zero tractive power. Decel modes based on zero battery and motor power are also forward modeled. Multi-mode decel (using a low power decel mode with regenerative braking) is presented as a set of intermediate strategies. An example vehicle using these strategies is modeled in fixed-route simulations, and scoring is based on travel time, energy consumption, and bias towards minimizing one of those metrics. Regenerative braking has the lowest travel time, and coasting the lowest energy consumption, but such bias increases overall cost. Multi-mode strategies lower overall cost by balancing reductions in travel time and energy consumption. Model sensitivity to grade and accessory load fluctuation makes it adaptable to different vehicles and environments. Simulation results demonstrate how regen braking alternatives could be modeled to enhance connected and automated vehicle systems in battery electric vehicles.
Electrically Heated Catalyst: A Powerful Tool for Aftertreatment Optimization
Authors: Jean Emmanuel , Goncalves Maxime
Published: April 2023

New electrical exhaust aftertreatment heating systems are in development to address the expected Euro7 regulation in Europe. These systems considerably shorten the light =-off time of the catalyst, even under extreme boundary conditions, for example start and drive away at -7°C. The pollutant limits foreseen for Europe are less severe than for example a US Tier3/Bin30 level, but the boundary conditions considered (temperature, altitude, driving patterns) are much broader than on the chassis dyno cycle. CARB has proposed within the ACCII draft further development of the LEVIII regulation to eliminate loopholes and ensure that internal combustion engines emissions remain low while transitioning the fleet to Zero emission vehicles. A proposal with similar scope from the EPA on federal level is expected.

This paper shows how the Electrical Heated Catalyst (EHC) technology is developed and optimized and points out the differences between US and European requirements. The use of EHC allows a single system to address several aspects of the future US regulations. Simulation and test results have been completed on different levels: heater, full catalyst system, engine, vehicle. These different aspects are displayed and discussed, along with the key parameters of the EHC system, especially voltage, power, thermal inertia and control technologies. Finally, further perspectives are given on the potential of the system to reach a near Zero emissions level on vehicle.
The Influences of Testing Conditions on DOC Light-Off Experiments
Authors: Xi Yuanzhou , Ottinger Nathan , Kiani Daniyal , Liu Z. Gerald
Published: April 2023

Diesel oxidation catalyst (DOC) is one of the critical catalyst components in modern diesel aftertreatment systems. It mainly converts unburned hydrocarbon (HC) and CO to CO2 and H2O before they are released to the environment. In addition, it also oxidizes a portion of NO to NO2, which improves the NOx conversion efficiency via fast SCR over the downstream selective catalytic reduction (SCR) catalyst. HC light-off tests, with or without the presence of NOx, has been typically used for DOC evaluation in laboratory. In this work, we aim to understand the influences of DOC light-off experimental conditions, such as initial temperature, initial holding time, HC species, with or without the presence of NOx, on the DOC HC light-off behavior. The results indicate that light-off test with lower initial temperature and longer initial holding time (at its initial temperature) leads to higher DOC light-off temperature. Depending on the types of HC used, the presence of NOx can also influence HC light-off. Overall, the different HC light-off behaviors from different testing conditions are mainly affected by the adsorption of HC on the catalyst during the test as evidenced by HC adsorption and TPO (temperature programmed oxidation) test results.
Evaluation of the Effectiveness of Diesel Particulate Filter Cleaning Methods and their Effect on Fuel Consumption
Authors: Bonsi Adime Kofi , Surcel Marius-Dorin , Szathmary Gabor
Published: April 2023

The negative effects of long-term exposure to soot and particulate matter emissions from diesel exhaust on the human health have been widely acknowledged due to the harmful substances that exhaust gas contains. Regulators have established strict programs to determine the performance and reliability of emissions after-treatment systems and devices. Tests were conducted to evaluate the efficacy of three diesel particulate filter (DPF) cleaning methods: 1) thermal and pneumatic cleaning, 2) ultrasonic cleaning, and 3) aqueous cleaning methods. A novel non-destructive method to quantify soot and ash deposits in the filters was developed, validated and used to determine the effectiveness of the identified cleaning methods. Given the number of different cleaning methods available, testing against a set of standard parameters provided accurate comparative results. Test results showed at least satisfactory ratings for all cleaning systems that were evaluated, while two systems stood out with very good ratings, with up to 96% of deposits removed by one cleaning system. Fuel consumption tests based on SAE J1321 and TMC RP 1102A Fuel Consumption Test Procedure – Type II were also performed to determine the effect of diesel particulate filter cleaning methods on fuel consumption. The tests were conducted on a high-speed test track at a constant speed of 105 km/h (65 mph). Test results showed that excluding the fuel consumed during passive regeneration, the level of obstruction of the diesel particulate filter showed little impact on fuel consumption. Results comparing the fuel consumption of a cleaned DPF versus that of a used DPF ranged from 0.65% to 1.43%.
Laboratory sulfation of an ammonia slip catalyst with a real-world SO
2
concentration
Authors: Ottinger Nathan , Xi Yuanzhou , Kiani Daniyal , Liu Z. Gerald
Published: April 2023

Upcoming, stricter diesel exhaust emissions standards will likely require aftertreatment architectures with multiple diesel exhaust fluid (DEF) introduction locations. Managing NH3 slip with technologies such as an ammonia slip catalyst (ASC) will continue to be critical in these future aftertreatment systems. In this study, we evaluate the impact of SO2 exposure on a state-of-the-art commercially available ASC. SO2 is co-fed at 0.5 or 3 ppmv to either approximate or accelerate a real-world exhaust SO2 impact. ASC performance during sulfur co-feeding is measured under a wide variety of simulated real-world conditions. Results indicate that the loss of NO conversion during SCR is dependent on the cumulative SO2 exposure, regardless of the inlet SO2 concentration. Meanwhile, N2O formation under SCR conditions is nonlinearly affected by SO2 exposure, with formation increasing during 0.5 ppmv SO2 exposure but decreasing in the presence of 3 ppmv SO2. TPO experiments reveal the formation of ammonium sulfate species, but only after prolonged SO2 exposure at 0.5ppmv or accelerated SO2 exposure at 3 ppmv. Reactivation at 550°C is sufficient to recover ASC reactivity following multiple SO2 exposure tests in all cases. These findings are especially relevant for the development of diesel exhaust aftertreatment accelerated aging protocols.
Soot Formation and Ignition Characteristics of Ethanol/Gasoline Blends in a Rapid Compression Machine
Authors: Gross Joseph , Chowdhury Musharrat , Dempsey Adam , Allen Casey
Published: April 2023

With the ever-increasing demand for sustainable energy, alcohol fuels have garnered interest for use in heavy duty engines. The significant infrastructure for ethanol production and blending of ethanol with gasoline make these fuels/fuel blends desirable candidates. However, development of heavy duty engine technology that is capable of burning alcohol fuels while retaining the advantages of traditional diesel combustion requires an improved understanding of the soot formation for these fuels under conditions relevant to mixing-controlled combustion. This work uses an extinction diagnostic to study the sooting tendency of ethanol and gasoline/ethanol blends ranging from E10 to E98 during ignition in a homogeneous environment. Experiments were conducted in a rapid compression machine (RCM) for compressed conditions of 20 ± 1 bar and an approximately constant temperature (± 10K) which was unique for each fuel. For a given soot volume fraction, a linear relationship was observed between ethanol content and the equivalence ratio in which that soot volume fraction was formed. Accounting for the oxygenated nature of ethanol, E85 and E98 fuels produced similar amounts of soot at a given ϕox,, suggesting other factors outside of fuel oxygen content, such as fuel morphology, impact soot formation. Ignition delay data is reported for compressed pressures of 20 ± 1 bar and compressed temperatures ranging from 633 – 670 K for E10 and 771 – 789 K for E98. Varying pressures for E10 and E98 at conditions producing similar soot volume fractions demonstrated a linear dependence of soot formation on pressure, regardless of if the pressure considered was at top dead center or peak combustion pressure. The data gleaned from this work will be used to select soot models and chemical kinetic mechanisms for RCM simulations to ultimately model heavy duty engine technology with the studied fuels.
Development of High Performance Coated Gasoline Particulate Filter
Authors: Morita Tomoko , Hashimoto Masanori , Seki Chiaki , Satoh Naohiro , Nakanishi Yui
Published: April 2023

In recent years, emission regulations have become stricter as part of the shift toward decarbonization. Particularly in Europe, the PN (Particulate Number) regulation has grown stricter, and further enhancement of PN filtration efficiency of GPF (Gasoline Particulate Filter) is required. However, as PN filtration efficiency is enhanced, pressure drop increases. There is a trade-off between PN filtration efficiency and pressure drop. In particular, coated GPF (cGPF) tends to deteriorate this trade-off relationship compared to uncoated GPF because of the coating of the catalyst. On the other hand, cGPFs have three-way performance, which can reduce the number of catalyst converters in the exhaust system. Therefore, we tried to establish a high performance cGPF by enhancing the trade-off relationship between PN filtration efficiency and pressure drop. We have used various cGPFs to analyze the coating state and substrate and characterize the functionality to understand the relationship between functions and above analysis items. The results showed that regardless of the substrate pore size, PN filtration efficiency was enhanced by reducing the neck diameter formed by the catalyst coated on the substrate. It was also found that the pressure drop was lowered by increasing the pore size of the substrate. Based on these findings, we established the concept of a high-performance cGPF, in which reduction of pressure drop is achieved by increasing the pore size of the substrate, while PN filtration efficiency is enhanced by reducing the neck diameter formed by the catalyst coated there. We have developed a prototype GPF catalyst with this concept and verified its function. This GPF achieved both PN filtration efficiency and pressure drop targets.
New Generation Diesel Particulate Filter for Future Euro7 Regulation
Authors: Nakagoshi Yuta , Mori Kazuya , Tanaka Katsunori , Furuta Yasuyuki , Aoki Takashi , Yoshioka Fumihiko , Kato Kyohei
Published: April 2023

Diesel Particulate Filters (DPF) are becoming mandatory for many Heavy Duty Vehicle (HDV) and Non Road Mobile Machinery (NRMM) applications as the requirement for particulate filtration performance has increased over this past decade. In a previous study, a new generation of cordierite DPF was developed to meet the latest major emission regulations; PN-PEMS requirement for EuroVI StepE, while maintaining a lower pressure drop and high ash capacity. Despite the improvements made in the latest generation DPF material, the introduction of tighter particulate regulations demands further improvement in DPF technology. More specifically, PN emission limits for Euro7 under wide operation conditions in conjunction with PN down to 10nm, as described in the proposal from Consortium for Ultra Low Vehicle Emission (CLOVE), requires further improvement in PN filtration performance. Pressure drop, which may negatively influence the CO2 emissions, remains a key performance criteria. The DPF must also have high ash capacity per unit volume to ensure there is enough packaging space for the light off SCR, which is likely going to be essential in managing the severe NOx emissions limits. Furthermore, there is also the chance that other regions such as China and India may choose to adopt these stringent European regulations in an effort to achieve better air quality. To fulfill Euro7 requirement, DPF technologies will need to improve PN emission by more than one order of magnitude while sustaining equal or lower pressure drop and equal or higher ash capacity. This paper investigates the development of new generation Cordierite DPF, whose material concept was optimized to minimize both large and small pores to achieve a good balance between the trade-off performance of PN filtration and pressure drop. Both laboratory and engine bench tests were carried out to compare the performance of this state-of-the-art technology with the performance of the conventional material. The results are presented relative to the assumed Euro7 PN boundary conditions.
Sub-23nm Particle Emissions from China6 Gasoline Vehicles over
Various Driving Cycles
Authors: Feng Xiangyu , Li Chunbo , Li Weiwei , Chen Jian , Liu Yi , Liu Haixu , Wang Zequn , Chen Xiaolang
Published: April 2023

Sub-23nm particles emission from the light-duty vehicle is widely discussed now
and possible to be counted into the next stage emission legislation, such as
Euro7. In this article, 16 China6 gasoline vehicles were tested over the WLTC
and two surrogate RDE lab cycles for particulate number (PN) emission, the
difference between PN23 (particle size >23nm) and PN10 (particle
size>10nm) emission was analyzed. Testing results showed that the average
PN10 emission increased 59% compared to PN23, which will bring great challenges
for those vehicles to meet the future regulation requirement if sub-23nm
particle is counted. The sub-23nm particles emission was proportional to the
PN23 particles emission and generated mostly from the cold start or the
transient engine conditions with rich combustion. Compared to the proposal of
Euro 7, PN10 emission from some tested vehicles will need further two orders of
magnitude reduction. With the adoption of an advanced gasoline particulate
filter (GPF) sample, the most challenging vehicle achieved the PN10 emission
level of 3.3E10 #/km over the surrogate RDE cycle with GPF filtration efficiency
above 99% and fulfilled the potential EU7 requirement.
Year in Review: Progress towards Decarbonizing Transport and Near-Zero Emissions
Authors: Joshi Ameya
Published: April 2023

As in the past several years, we provide here an overview of recent major regulatory and technological changes for reducing emissions from the transport and off-road sector. In the past, this review was focused mostly on improvement in engine efficiency and tailpipe emissions of criteria pollutants. However, starting last year [1] we have increased the scope to broadly address the increased focus on greenhouse gas emissions and the emergence of various non-conventional fuel pathways to achieve the various decarbonization goals.

There are two broad themes that are emerging, and which we describe here. Firstly, that we are approaching the implementation of the last of the major regulations on criteria pollutant emissions from cars and trucks, led by Europe, through Euro 7 standards and US, through multi-pollutant standards for light- and heavy-duty vehicles. While electric vehicles are getting much of the headlines, most vehicles sold in the last year still had an internal combustion engine. OEMs therefore must continue to improve upon traditional ICE technologies to meet these upcoming standards, while also investing in alternative powertrains such as hybrids, electrics, hydrogen-powered vehicles, and engines running on renewable fuels. This is reflected in the increasing diversity of topics published and discussed at conferences, which we try to cover. Which brings us to the second theme: several major studies conclude that given the uncertainties of cost, infrastructure readiness, consumer acceptance and decarbonization of upstream energy generation, it is prudent to pursue all these diverse technology pathways. A ban on the sale of new internal combustion engines is one tool, but a limited one given that majority of the emissions are associated with those of the cumulative fleet, which will take decades to turnover.

We describe the major regulatory developments along with the implications for technologies, both for light- and heavy-duty vehicles.
The Hybrid IC Engine – Challenges of Hydrogen and E-Fuel Compatibility within Current Production Boundaries
Authors: Schoeffmann Wolfgang , Kapus Paul , Plettenberg Mirko , Howlett Michael
Published: April 2023

Increasingly stringent greenhouse gas and emission limits demand for powertrain electrification throughout all vehicle applications.

Beside fully electric powertrains different configurations of hybrid powertrains will have an important role in upcoming and future vehicle generations. As already discussed in previous papers, the requirements on the combustion engine in hybrid powertrains are different to those in a conventional powertrain solution, heading for brake thermal efficiency targets of 45% and above within the product lifecycle for conventional fuels.

Focus on product cost and production and assembly facility investment drives reuse of technology packages within modular powertrain technology platforms, with different combinations of internal combustion engines (ICE), transmissions, and e-drive-layouts.

The goal of zero carbon operation requires compatibility of ICE for sustainable fuels. Ethanol, Methanol and in particular Hydrogen has significant impact on ICE subsystems within modular engine platforms. High efficiency combustion concepts with high compression pressures, increased thermal loads, chemical impact dependent on material specifications, nearly oil-free combustion with optimized piston-bore interface to avoid preignition, active engine ventilation for safety requirements are topics to be considered.

Focus of the paper is on ICE technology packages required to meet future emission and efficiency targets within hybrid powertrains, as well as system optimization to provide compatibility for hydrogen and e-fuel operation within production boundaries of existing engine platforms.
The Be-Rex Engine-Generator: A Revolutionary Two-Stroke, Lightweight and Cost-Efficient Singular Unit
Authors: Bekking Pim , Puts Godfried , Spiller Martin , Bikas Georgios
Published: April 2023

Although electricity is necessary for a country's economic development, many countries lack suitable grid infrastructure. Portable generators offer a consistent electric supply in the event of a blackout.

Be-Rex B.V. develops and already assembled a revolutionary engine-generator prototype. It eliminates the use of camshafts, crankshafts and flywheels while integrating the generator parts into the same spherical housing. Thus, it constitutes a compact, lightweight and cost-efficient singular unit. There is no mechanical power output while the load of the engine is determined by the demanded load of the generator. The four combustion chambers are arranged in pairs on the north and south hemisphere and the magnets of the stator are placed circumferential at the equator of the spherical housing. The rotating disc and the joiner build the rotor of the generator. While developing the engine special emphasis has been put on its multi-fuel capability. Optimized gas exchange together with an efficient scavenging concept and the combustion system allow the atmospheric version of the prototype with a displacement volume of 400 cc to achieve 10 bar of indicated mean effective pressure (imep) when running on gasoline. Using 1-D WAVE simulations the same atmospheric version converted to ammonia fuel achieves 8 bar of imep.

First firing results of an engine generator prototype running on gasoline solidify the proof of concept. In the design section the main characteristics of the concept will be highlighted and the working principle will be explained. In the modelling approach section the methodology to tackle the leakage and the friction issues will be presented before the main results of the final design optimization will be discussed. Afterwards, the first experimental runs will be analyzed and finally some possible applications will be addressed.
Self-Cleaning EGR Valve for Current and Future Diesel Applications
Authors: Fachechi Nicola
Published: April 2023

In this paper, an innovative EGR valve, containing an integrated self-cleaning function to mitigate the progressive buildup of carbon deposits, is described. Conventional EGR valves use Butterfly and Poppet mechanisms to open and close a round shaped exhaust gas port with limited ability to remove exhaust carbon deposits from the affected surfaces and mechanical elements.

The self-cleaning EGR valve, instead, combining both rotational and linear motions, continuously sweeps its internal passages while delivering the gas flow, removing the carbon deposits before they can adhere to the internal surfaces.
Potential of a Hydrogen Fueled Opposed-Piston Four Stroke (OP4S) Engine
Authors: Zoldak Philip , Douvry-Rabjeau Julien , Zyada Antowan
Published: April 2023

The aim of this study is to develop a pathway towards Hydrogen combustoin on an opposed-piston four stroke engine (OP4S) by using 1D simulation code from Gamma Technologies. By its configuration, the OP4S engine has significant thermal efficiency benefits versus conventional ICE. The benefit of the OP4S is reduced heat losses due to elimination of the cylinder head, which increase the brake thermal efficiency.

A hydrogen-fueled (H2) opposed-piston four stroke (OP4S) engine was modeled using GTPower to determine the potential on performance, thermal efficiency and emissions targets. The 1D model was first validated on E10 gasoline using experimental data and was used to explore changes to fuel type in NG and H2, fueling location (TPI and DI), fuel mixture strength (stoichiometric and lean), for an optimized plenum volume and turbocharger selection.

The impact of these changes on volumetric efficiency, rated power, brake thermal efficiency and finally emissions for naturally aspirated and boosted conditions was determined. The simulation study demonstrates an engine design strategy for H2 fueled OP4S to meet power target of 20kW, brake thermal efficiency target of 40% and US EPA-Class II emission regulations for non-road small SI engine. The results also found that with a boosted stoichiometric burn direct injection H2 strategy combined with the OP4S can meet all performance and emission targets.
Methodology for Controlling Rattle Noise in Vehicle Turbocharger Wastegate System
Authors: Patel Lala Ram , Baladhandapani PhD Dhanasekar , Du Isaac
Published: April 2023

When a turbocharger exhaust-driven turbine wheel spins fast enough to produce the desired level of boost, a wastegate is typically used to allow the excess exhaust pressure to divert around the turbine wheel. By opening the wastegate (typically boost-pressure referenced), exhaust pressure bypasses the turbo’s turbine wheel to prevent the turbo from reaching an unsafe speed. To actuate wastegate, different actuating mechanisms like pneumatic, vacuum or electric are available, which regulates poppet valve positions e.g. full close, open or partially open.

In electronic wastegate valve, exhaust pressure pass through the bypass hole collides with the face of valve causing vibration. Such vibration is transmitted to the wastegate components causing rattle noise. It is challenging to design a wastegate mechanism which can sustain wastegate loads at high temperature and give quiet and robust performance within the full operating range of the engine. In order to improve the rattle noise, the mass damper for frequency generation for canceling the vibration is additionally applied used to reduce the clearance between parts. Valve spring is one of the critical components of the wastegate system, which absorbs impactive energy coming from wastegate loads exerts on the valve and reduces the vibrations of wastegate linkages transmitting towards the actuator side.

This paper describes methodology to design a functionally optimized wastegate linkage system and valve spring at an early stage. Multi-body dynamic (MBD) along with nonlinear transient dynamic FEA approach was developed for analyzing wastegate washer/cup spring system. The nonlinear FEA tools was used to assess component(s) design robustness due to the MBD generated dynamic loading in balance to geometry, thermal loading and material capabilities. Advanced valve spring and creep modeling are used to quantitatively study the spring relaxation after long time exposure to high temperature and stress. The simulation methodology outlined in this paper is used to investigate turbo wastegate linkage undergoing dynamically varying forces from the pulsation of the exhaust gas in transient engine operation, which results in identifying NVH issues and durability-relevant weak spots in the early-design phase and providing the development tool of robust design.

Testing is done to better understand wear and NVH of all components within the wastegate subsystem caused by engine induced mechanical vibrations. Data from this testing is used early in the turbocharger design and development process to validate analysis models and to size wastegate components
Investigation of Compressor Deposit in Turbocharger for Gasoline Engines (Part 1: Research on Deposit Formation Mechanism)
Authors: Ishizaki Noriya , Hirano Satoshi , Kuma Hiroshi , Ura Haruto
Published: April 2023

Contribution to carbon neutrality is one of the most important challenges for the automotive industry. As CO2 emission has been reduced through electrification such as hybrid electric vehicle (HEV) and plug-in hybrid electric vehicle (PHEV), internal combustion engines (ICEs) equipped in those powertrain systems are still necessary for the foreseeable future, and continuous efforts to improve fuel efficiency are demanded.

To improve powertrain thermal efficiency, direct-injection turbocharged gasoline engines have been widely utilized in recent years. Super lean-burn combustion engine has been researched as a next generation of turbocharged gasoline engines. Further utilization of turbochargers is expected. Compared with turbocharged downsized gasoline engines available in the current market, much higher boost pressure must be utilized to realize the super lean-burn engines. As a result, compressor housing temperature will be very high compared with the current market one. Blow-by gas containing engine oil mist is always recirculated into intake air upstream of the turbocharger compressor in the boosting operation. Therefore, the possibility of deposit formation derived from the engine oil mist is increased.

It is very important to inhibit the deposit formation for the realization of more efficient turbocharged gasoline engines and the reduction of vehicle CO2 emission. In this research, it is expected that solutions to inhibit the deposit formation will be found by clarification of the condition and the mechanism of this deposit formation in the turbocharged gasoline engines.
NVH Simulation and Validation of a P3 Hybrid Driveline
Authors: Ba Jing , Sun Zhaohui
Published: April 2023

This paper focuses on a P3 HEV drivetrain for a performance vehicle with a 2-speed gear shift system. The drivetrain NVH performance varies at different gear and different loading conditions, therefore creates a new level of challenges in optimizing the system. This paper presents the methodologies in optimizing the system NVH, including noise sources from both gearbox and eMotor. CAE modeling methods are discussed and illustrated for their usage in optimizing both structural and acoustic responses. Reasonable correlations to test data are achieved and presented.
A Method for Estimating Hysteresis of Automatic Tensioner and Analysis of Hysteresis Variations with Tensioner Parameters
Authors: Diao Qiangyou , Wan Lixiang , Chen HouChong , Ding Quanyu , Yan Yuanqing
Published: April 2023

The automatic tensioner is one of the important parts of the front end accessory drive system of the automobile engine. The tensioner uses the relative slip of the friction pair to generate friction torque, which makes its own system have hysteresis characteristics, so that it can automatically control the tension of the belt in the attachment system and improve the NVH performance of the attachment system. This paper takes the automatic tensioner of an engine front end accessory drive system as the research object, and establishes an analytical model and a finite element simulation model for the calculation of the hysteresis characteristics of the tensioner. The hysteresis characteristic test of the tensioner was carried out to verify the correctness of the analytical model and the finite element model, the error between the calculation results and the test results was analyzed, the proportions of the three friction pairs were compared, and the factors affecting the performance of the tensioner were determined. Key parameters, analyzed the effect of key parameters on the working torque and damping ratio of the tensioner. The method proposed in this paper takes into account the change of the initial gap and contact state between the tensioner spring and the damping bracket, and has stronger versatility. It can effectively predict the hysteresis characteristics of the automatic tensioner, and has practical engineering significance for the design and development of the tensioner.
Experimental Study on the Relationship between Combustion and Vibration in a Gasoline Engine Part1 Study Overview and the Characteristics of Combustion’s Exciting Force
Authors: Sato Hironao , Oba Masahiro , Hiromoto Takashi , Sato Kiyofumi , Sonobe Toshiyuki , Hayakawa Satoru , Morikawa Koji , Moriyoshi Yasuo , Sekine Noriaki
Published: April 2023

This study focused on the vehicle interior noise caused by combustion in which vibration transmission is the main component at high speed and high load region. A phenomenon in which both the combustion’s exciting force and the structure’s exciting force are combined is defined as vehicle interior noise caused by combustion. Conventionally, combustion and vibration are often discussed in terms of the average cycle, but considering the nonstationary property of vibration, in this paper analyzed the combustion characteristics for cycle-by-cycle and investigated indicators for the combustion’s exciting force. The engine vibration is affected by heat release characteristics even with the same engine structure specifications. The heat release characteristics were determined as indicators for the combustion’s exciting force. Transfer Path Analysis (TPA) revealed that there is piston transmission in the target frequency band. Through eigenvalue analysis, it was found that there was no resonance with the eigenvalue of the structures in the target frequency band. Even with the same combustion characteristics, the engine vibration is affected by piston specifications. Piston motion characteristics were determined as indicators for the structure’s exciting force. In this paper, after overview the impact of each exciting force on vibration, the heat release characteristics of the combustion’s exciting force and the indicators for vibration suppression are mainly discussed.
Research on Intake System Noise Prediction and Analysis for a Commercial Vehicle with Air Compressor Model
Authors: Zhao Yongnan , Cai Yaoyu , Zhou Zhengdao , Xu Zhicheng , Chen Shuming
Published: April 2023

Intake system is an important noise source for commercial vehicles, which has a significant impact on their NVH performance. To predict the intake noise more accurately, a new one-dimensional prediction model is proposed in this paper. An air compressor model is introduced into the traditional model, and the acoustic properties of the intake system are simulated by GT-power. The simulation data of the inlet noise is obtained to make a comparison with the inlet noise data acquired from a test. The result shows that the proposed model can make a more precise prediction of the inlet noise. Compared with the traditional model, the proposed model can identify the noise coming from the air compressor, and achieve a more accurate prediction of the total sound pressure level of the inlet noise.
New Cam Profile Design Approach, Analysis and Testing for Extreme High Efficiency Internal Combustion Engine Development
Authors: Ortolani Paolo , Nation Frank
Published: April 2023

The main objective of this work is to describe the design and testing of novel cam profiles, which are key for efficiency demonstration on a new class of internal combustion engine (ICE). A recuperated split cycle engine (RSCE) has unique demands for valve lift, duration and phasing when compared to a conventional 4-stroke. In particular, good control of the expander intake valve opening (IVO) appears to be necessary to achieve high efficiency.

Commercial computer programs available for valvetrains have been developed for conventional 4-stroke engines and, typically, these are focused on profile analysis rather than design. Often, the standards and recommended parameters are derived from historical 4-stroke data that may not fulfill the requirements of a new class of ICE, where boundary conditions have drastically changed.

In this paper, the cam profile requirements, functions, design, analysis and test results from a research and development (R&D) program of a heavy duty (HD) recuperated split cycle engine are reported. This included novelties in cam profile generation, technology and the materials used. This work is based on requirements, hypotheses and problem simplifications, supported by virtual validation, FEM analyses, spreadsheet calculations, component specifications and 1D simulations. Development has also been done by suppliers to satisfy the project requirements, alongside a compromise between technology selection and the pressing need to respect an extremely short time frame for component procurement.

Whilst this work refers to a specific engine development program, the methodology described in this paper has been more generally considered for the new class of ICE and can be successfully applied to other projects with common development targets (time to market, fuel efficiency and development costs).
Efficient Physics-Based System Level Thermal Management for Electric Drive Units using Reduced Order Modeling Techniques Assisted by Neural Networks
Authors: Yashwanth Bangalore Lingaraj , Kolesnikov Alexy , Ronning Jeff
Published: April 2023

Efficient thermal management is essential in high power density electric drive units (EDUs) due to limited space and working environment. Major heat sources in EDUs are from the inverter, motor and gearbox. System level thermal response prediction models comprising various components within the EDU are of interest from both product performance and software controls standpoint.

A system level physics-based lumped parameter thermal network (LPTN) model is built in a one-dimensional (1D) framework using inputs from empirical, electromagnetic, three-dimensional conjugate fluid/heat transfer analysis and test data to predict the component temperature within the EDU. Empirical models were used to calculate heating due to efficiency loss from the gearbox. The thermal loses from the motor are estimated as outputs from electromagnetic simulations. Three-dimensional computational fluid dynamics (CFD) conjugate heat transfer (CHT) simulations were also used at both system and component level to determine heat transfer within the gearbox, motor and inverter. Later due to memory constraints of the microcontroller unit (MCU) the LPTN model is further reduced using a novel temperature estimation based deep neural network to predict component temperatures of interest within the EDU for a given duty cycle.
Integrated Analytical Approach for Electronic Locking Differential Systems
Authors: Rangarajan Moogoondaraja , Ilunga Ralph , Roy Nantu , Mehta Yogesh
Published: April 2023

Electronically locking differentials that have dog-clutches may not always have a smooth engagement. The duration of the engagements needs to be quantified, and the different types of engagement need to be qualified. The engagement time is dictated by both the mechanical and electrical sub-systems of the differential. Three different analytical methods were developed to simulate engagement. The first method uses Simulink to co-simulate the electromagnetic behavior of the actuator in ANSYS Maxwell, and the multibody dynamic behavior of the differential in MSC ADAMS. The second method simulates the mechanics of the differential in AMESim, where an equation for the electromagnetic force inside the actuator is integrated into the model. The third method leverages the former two methods by combining the MSC ADAMS multibody dynamic behavior with integrated equation for the electromagnetic force inside the actuator. Correlations between the analytical approaches and experimental test data have been completed.
Sensorless Control of a Brushless Motor for the ESC Unit
Authors: Kawamura Hikaru , Kokubo Koichi , Naito Masayuki , Iida Takanori , Takahashi Atsushi , Takahashi Tomoya
Published: April 2023

In general, automatic braking uses an electric stability control (ESC) hydraulic unit that can automatically increase the hydraulic pressure in the wheel cylinder (hereinafter called wheel pressure), independent of the driver’s braking operation. The hydraulic unit should have sufficient pressure response to apply autonomous emergency braking (AEB). It was necessary for the hydraulic unit to have a high flow rate for the pressure response.

To satisfy the performance requirements of the AEB, a brushless motor, which has a high maximum rotational speed and good response, is adopted for the hydraulic unit. Furthermore, sensorless control, which does not require a rotation angle sensor, has been developed so that the motor size can be small and common to conventional units.

The developed sensorless control can switch the driving methods in three states: pre-rotation, low speed, and high speed. In the pre-rotational state, the magnetic poles are judged to quickly determine the initial position of the motor rotor. The rotational speed in the low-speed range was estimated based on the disturbance superimposition method. Subsequently, the rotational speed in the high-speed range was estimated based on the extended guidance method. The sensorless control can drive the brushless motor with the same performance as that of a system equipped with a rotation angle sensor over a wide range of rotational speeds.

A sensorless control system that has the same performance as a system equipped with a rotation angle sensor was developed, which allows the miniaturization of the motor.
Personalized Optimal Gearshift Schedule for Multi-Speed Battery Electric Vehicles
Authors: Yin Xiaofeng , Chen Bo , Qing Huihong , He Hao , Wu Zhimin
Published: April 2023

To further enhance the comprehensive performance of multi-speed battery electric vehicles (MSBEVs) and meanwhile represent the driver’s expectation on performance, we need to consider the power performance, energy economy and driver’s intention together in the optimization of gearshift schedule. An optimization approach for personalized optimal gearshift schedule (POGS) for MSBEVs is put forward to tackle this issue. A quantification method for driver’s intention based on fuzzy neural network is proposed at first, which takes velocity, strength of accelerator pedal and its change rate as input, and takes driver’s expectations on performance as output. The optimization problem for POGS is then formulated with comprehensive evaluation function as goal, in which the driver’s expectations on performance are used as weights of sub-objective functions corresponding to the power performance and the energy economy, respectively. And a particle swarm optimization algorithm (PSO) is put forward to solve the optimization problem. To evaluate the proposed optimization approach, we completed parameters design for a two-speed drivetrain and a single-speed drivetrain with similar power performance, respectively. The POGS’s for the two-speed BEV are optimized, which are finally used in the power performance and WLTC driving cycle tests. Results show that the acceleration time from 0-100 km/h decrease with the increase of driver’s expectation on power performance, the energy consumption under WLTC driving cycle decrease with the increase of driver’s expectation on energy economy, and the energy consumption of the two-speed BEV is quite less than that of the single-speed BEV.
Assessment of Fuel Consumption of a co-Optimized Gasoline Compression Ignition Engine in a Hybrid Electric Vehicle Platform
Authors: Zoldak Philip , Zhu Shengrong , Ha Kyoung Pyo
Published: April 2023

Increasing regulatory demand to reduce CO2 emissions has led to an industry focus on electrified vehicles while limiting the development of conventional internal combustion engine (ICE) and hybrid powertrains. Hybrid electric vehicle (HEV) powertrains rely on conventional SI mode IC engines that are optimized for a narrow operating range. Advanced combustion strategies such as Gasoline Compression Ignition (GCI) have been demonstrated by several others including the authors to improve brake thermal efficiency compared to both gasoline SI and Diesel CI modes. Soot and NOx emissions are also reduced significantly by using gasoline instead of diesel in GCI engines due to differences in composition, fuel properties, and reactivity. In this work, an HEV system was proposed utilizing a multi-mode GCI based ICE combined with a HEV components (e-motor, battery, and invertor).

To determine the total fuel consumption over the FTP75 drive cycle, a fueling map from a multi-mode GCI combustion presented in a previous study was used as the input data set for the 1D HEV drive cycle model (GT Drive) of a mid-sized SUV. An HEV operation strategy was proposed and followed by parametric studies of components including the e-motor sizing (20 kW to 80kW) and the battery capacity (2Ah to 8Ah), and evaluation on their impacts on fuel consumption.