Technical Papers - SAE Mobilus

SAE Technical Papers are written and peer-reviewed by experts in the automotive, aerospace, and commercial vehicle industries and provide the latest advances in technical research and applied technical engineering information.

Items (112,279)

BALL BEARINGS.

060002To be published on 01/01/2099

HESS, HENRY

Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement

2024-01-3356

04/23/2025

ABSTRACT This paper presents a quantitative analysis and comparison of fuel economy and performance of a series hybrid electric HMMWV (High Mobility Multi-purpose Wheeled Vehicle) military vehicle with a conventional HMMWV of equivalent size. Hybrid vehicle powertrains show improved fuel economy gains due to optimized engine operation and regenerative braking. In this paper, a methodology is presented by which the fuel economy gains due to optimized engine are isolated from the fuel economy gains due to regenerative braking. Validated vehicle models as well as data collected on test tracks are used in the quantitative analysis. The regenerative braking of the hybrid HMMWV is analyzed in terms of efficiency from the kinetic energy at the wheels to the portion of regenerative power which is retrievable by the battery. The engine operation of both the series hybrid and conventional HMMWV are analyzed using a 2-D bin analysis methodology. Finally, the vehicle model is used to make

Nedungadi, Ashok, Masrur, Abul, Khalil, Gus

Mixed Wettability Influence on Water Droplet Behaviour in a PEM Fuel Cell Channel

2024-32-003704/18/2025

The utilization of hydrogen in low-temperature Proton Exchange Membrane Fuel Cells (PEMFCs) stands out as a compelling prospect for driving a widespread shift towards green industry practices. Despite significant advancements, a comprehensive understanding of water behaviour and dynamics within PEMFCs remains crucial for their extensive integration in propulsion applications. Striking a delicate balance between flooding and drying conditions poses a challenge for achieving stable and efficient PEMFC operation. In this study, a preliminary experimental investigation was conducted focusing on carbon-paper Gas Diffusion Layer (GDL) and gas channel walls. The static, advancing and receding contact angles were measured and utilized as boundary conditions for simulations. The influence of membrane humidity was also examined during the experimental campaign. 3D CFD simulations were performed on a straight portion of a PEMFC channel with a selected domain length of 5 mm and a section of 1x1 mm

Merola, S. S., Antetomaso, C., Irimescu, A., Vaglieco, B. M., Jannelli, E.

Virtual Calibration Approach to the Development of Control Systems and Strategies for Hybrid L-Category Vehicles

2024-32-006604/18/2025

Hybrid powertrain for motorcycles has not been widely adopted to date but has recently shown significant increased interest and it is believed to have great potential for fuel economy containment in real driving conditions. Moreover, this technology is suitable for the expected new legislations, reduced emissions and enables riding in Zero Emissions Zones, so towards a more carbon neutral society while still guaranteeing “motorcycle passion” for the product [1, 2]. Several simulation tools and methods are available for the concept phase of the hybrid system design, allowing definition of the hybrid components and the basic hybrid strategies, but they are not able to properly represent the real on-road behaviour of the hybrid vehicle and its specific control system, making the fine tuning and validation work very difficult. Motorcycle riders are used to expect instant significant torque delivery on their demand, that is not properly represented in legislative cycles (e.g. WMTC); rider

Antoniutti, Christian, Sweet, David, Hounsham, Sandra

Dependency of Gear Honing Machine Processing Accuracy on Machine Vibration and the Vibration Reduction Considering Contribution

2024-32-002004/18/2025

In recent years, accurate gear processing is required for various products to improve efficient power transmission and small noise and vibration. On the other hand, the accuracy tends to be worse by high speed processing for increasing production efficiency. Therefore, we investigated relationship between gear honing machine vibration and the accuracy. The vibration acceleration of the honing machine was measured at various conditions, and the gear accuracy was measured after processing. As results, the accuracy was observed to be affected by both the original gear accuracy before honing processing and the gear secondary rotational vibration of the machine in operation. Subsequently, we applied transfer path analysis (TPA) to investigate which directional force in operation increased the vibration. As the results, the contribution from the input force at gear processing point along normal direction was the main contributor. Then, vibration transmission characteristics of the machine

Hanioka, Hiroaki, Ogawa, Yunosuke, Yoshida, Junji, Onishi, Yoichi, Kurokawa, Yasuhiro

Study on the Optimal Pre-Chamber Geometry for Active Pre-Chamber Gas Engines

2024-32-002304/18/2025

In a pre-chamber engine, fuel in the main-chamber is ignited and combusted by the combustion gas injected from the pre-chamber. Therefore, further fuel dilution is possible and thermal efficiency can be also improved. However, adding a pre-chamber to an engine increases the number of design parameters which have a significant impact on the main combustion and the exhaust gas. Then, in this study, the optimum geometry of the pre-chamber in an active pre-chamber gas engine was investigated. The considered parameters were the volume of pre-chamber, the diameter of a nozzle hole, and the number of nozzle holes. 18 types of pre-chambers with different geometries were prepared. Using these pre-chambers, engine experiments under steady conditions were conducted while changing the conditions such as engine speeds, mean indicated pressure and air excess ratio. Based on the experimental data, neural network models were constructed that predict thermal efficiency, NOx and CO emissions from the

Yasuda, Kotaro, Yamasaki, Yudai, Sako, Takahiro, Takashima, Yoshitane, Suzuki, Kenta

Development of Cylinder Deactivation Control during Idle for Conventional Engines

2024-32-001904/18/2025

This report examines the advancement and utilization of cylinder deactivation technology that enhances fuel efficiency in conventional engines without hardware modifications. It operates by halting fuel supply to some of the cylinders in multi-cylinder engines and increasing the output power of the remaining active cylinders to maintain an idle state. By implementing this technology in the mass-produced 90° V-twin engine, the U502, and deactivating one of its two cylinders, fuel consumption during idling is reduced by over 30%. The focus of this study is on the technology developed to minimize engine speed fluctuations during the transition to cylinder deactivation and reactivation for the engine. By making various modifications to the fuel injection control sequence and optimizing the throttle opening of each cylinder in idle and driving conditions, engine speed fluctuations were minimized. This allows users to reduce fuel consumption while maintaining the engine’s original

YANAGIDA, Shoji

Effect of Ignition Position on Lean Limit of Main Chamber Combustion in Pre-Chamber Ignition

2024-32-002204/18/2025

An engine was built in this study that enabled the conditions in a pre-chamber and in the main combustion chamber to be visualized simultaneously for the purpose of elucidating the mechanism of pre-chamber combustion. An investigation was made of how the state of pre-chamber combustion, including the location of initial flame generation and its subsequent propagation, influenced pre-chamber jet combustion. The state of pre-chamber combustion was intentionally varied by changing the position of pre-chamber ignition. As a result, it was found that changing the position of pre-chamber ignition varied the location where the pre-chamber flame occurred, how the flame propagated and the timing and strength of the flame jet that was ejected into the main chamber. The results revealed that these differences in the state of pre-chamber combustion markedly changed the rate of combustion fluctuation, combustion period, lean-burn limit and other combustion characteristics depending on the ignition

Onuma, Takeru, Yamada, Hiroto, Ugajin, Taisei, Shinozaki, Kaito, Tahara, Ryota, Iijima, Akira

Identification of Input Force and Contribution for Electric Power UnitUtilizing Virtual Point

2024-32-001504/18/2025

In this study, vibration characteristics inside an electric power unit at gravity center where direct measurement is impossible were estimated by using virtual point transformation to consider guideline for effective countermeasures to the structure or generated force characteristics inside the power source. Vibration acceleration, transfer function and the generated force in operation at the gravity center of the electrical power source were obtained by vibration characteristics at around the power source which can be measured directly. In addition, the transfer functions from the gravity center to the power source attachment points on the product were also estimated. And then, the contribution from the gravity center to the power unit attachment point was obtained by multiplying generated force with the transfer function. As results, the obtained total contribution was almost same with the actual measured vibration at the attachment point. Furthermore, the rotational contribution

Kubo, Ryoma, Hara, Kenta, Yoshida, Junji

Necessity of Body Torsional Rigidity of Personal Mobility Vehicles (PMVs) with an Inward Tilting Mechanism

2024-32-001304/18/2025

In traditional four-wheeled automobiles, the imbalance between the roll moment, which is the product of the centrifugal force during a turn acting on the center of gravity and the height of the center of gravity, and roll stiffness, which is the product of the left-right difference in tire vertical load and the tread width and commonly used among automotive suspension engineers, of the front and rear sections necessitates body torsional rigidity. However, there is a lack of specific cases and guidelines for constructing the body structure of three-wheeled PMVs (Personal Mobility Vehicles) with a tilting mechanism from the perspective of vehicle dynamics characteristics. In this paper, the basic considerations related to the dynamics of such three-wheeled PMVs are investigated. We use the term “torsional rigidity” to refer to the stiffness as the torsional deformation of the body itself, and the term “roll stiffness” to refer to the moment that counteracts the roll moment during a turn

Haraguchi, Tetsunori, Kaneko, Tetsuya

Fuel Film Measurement in a SI Gasoline Engine Using a Newly Developed MEMS Sensor

2024-32-007104/18/2025

The previously developed capacitance sensor for detecting a liquid fuel film was modified to apply to the in-cylinder measurement. On the developed sensor surface, comb-shaped electrodes were circularly aligned. The capacitance between the electrodes varies with the liquid fuel film adhering. The capacitance variation between the electrodes on the sensor surface was converted to the frequency variation of the oscillation circuit. In the previous study, it was revealed that the frequency of the oscillation circuit varies with the variation of the liquid fuel coverage area on the sensor surface. The developed sensor was installed in the combustion chamber of the rapid compression and expansion machine, and the performance of the developed sensor was examined. Iso-octane was used as a test fuel to explore the sensor that had been developed. As a result, the adherence of the liquid fuel directly injected into the cylinder was successfully detected under the quiescent and motoring

Kuboyama, Tatsuya, Moriyoshi, Yasuo, Takayama, Satoshi, Nakabeppu, Osamu

3D-CFD Simulations of H2 ICEs: A Preliminary Evaluation of a Laminar Flame Speed Correction for Thermo-Diffusive Instability

2024-32-007404/18/2025

In recent years, climate change and geopolitical instability have intensified the focus on sustainable power generation. This shift seeks alternatives that balance environmental impact, cost-effectiveness, and practicality. Specifically, in transportation and power generation, electric motors face challenges against internal combustion engines due to the high cost and mass of batteries required for energy storage. This makes electric solutions less favorable for these sectors. Conversely, internal combustion engines, when properly fueled, offer cost-effectiveness and a quasi-environmentally-neutral option. To address these challenges, researchers have explored e-fuels derived from renewable sources as a carbon-neutral supply for internal combustion engines. Among these, hydrogen is particularly promising. In hydrogen-powered internal combustion engines, 3D-CFD (Computational Fluid Dynamics) in-cylinder models are crucial. Once validated, these models can speed up the design process. A

Sfriso, Stefano, Berni, Fabio, Breda, Sebastiano, Fontanesi, Stefano, Cordisco, Ilario, Leite, Caio Ramalho, Brequigny, Pierre, Foucher, Fabrice

RDE Methodology Development for Motorcycle Emissions Assessment

2024-32-007304/18/2025

The transfer of conditions and regulations for RDE testing from passenger cars to motorcycles is a non-trivial undertaking. Motorcycles exhibit significant differences in construction and usage compared to cars, necessitating a distinct set of requirements for equipment and methodology. Currently available PEMS are hindered by their relatively large size and weight due to the embedded measurement technology and external power supply. The weight of, at least 50kg, poses a substantial additional load, leading to a deviation and, on average, higher load collective of the engine during RDE measurement rides. Beyond these structural parameters, the actual propulsion system and subsequent exhaust system introduce another challenge when employing PEMS on motorcycles. An unfavorable combination of the ratio of engine displacement to the volume of the exhaust system and long or unequal ignition intervals leads to pulsations, which has a considerable impact on the differential pressure-based

Schurl, Sebastian, Keller, Stefan, Lankau, Mathias, Hafenmayer, Christian, Schmidt, Stephan, Kirchberger, Roland

Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces

2024-32-004604/18/2025

The rear swing arm, a crucial motorcycle component, connects the frame and wheel, absorbing the vehicle’s load and various road impacts. Over time, these forces can damage the swing arm, highlighting the need for robust design to ensure safety. Identifying potential vulnerabilities through simulation reduces the risk of failure during the design phase. This study performs a detailed fatigue analysis of the swing arm across different road conditions. Data for this research were collected from real-vehicle experiments and simulation analyses, ensuring accuracy by comparing against actual performance. Following CNS 15819-5 standards, road surfaces such as poorly maintained, bumpy, and uneven roads were tested. Using Motion View, a comprehensive multi-body dynamic model was created for thorough fatigue analysis. The results identified the most stress-prone areas on the swing arm, with maximum stress recorded at 109.6N on poorly maintained roads, 218.3N on bumpy surfaces, and 104.8N on

Chiou, Yi-Hau, Hwang, Hsiu-Ying, Huang, Liang-Yu

Novel Statistical Modelling-Based Approach for Exhaust Mass Flow Calculation in Motorcycles

2024-32-007204/18/2025

The exhaust mass flow measurement for motorcycles poses a unique challenge due to presence of pulsations arising from an unfavorable combination of the engine displacement-to-exhaust system volume ratio and the long or even unequal ignition intervals. This pulsation phenomenon significantly impacts the accuracy of the differential pressure-based measurement method commonly employed in on-board measurement systems for passenger cars. This paper introduces an alternative approach calculating exhaust mass flow in motorcycles, focusing on statistical modelling based on engine parameters. The problem at hand is rooted in the adverse effects of pulsations on the differential pressure-based measurement method used in the EFM. The unfavorable combination of engine characteristics specific to motorcycles necessitates a novel approach. Our proposed alternative involves utilizing readily available OBD parameters, namely engine speed and calculated engine load as there is mostly no data for intake

Schurl, Sebastian, Sturm, Stefan, Schmidt, Stephan, Kirchberger, Roland

A Two-Step Approach for Tire Lateral Force Observation for Motorcycles

2024-32-004304/18/2025

This study presents a two-step method for estimating motorcycle tire lateral forces, which are critical to the safety of driver assistance systems. In the pre-filtering stage, a partial attitude of the motorcycle is estimated using a Kalman filter and a kinematic model. In the observation stage, the side slip angle and subsequently the tire lateral forces are provided by a sliding mode observer. It extends previous research by incorporating both out-of-plane and in-plane dynamics. The paper also proposes an approach for selecting the Kalman filter parameters. An approach to identify the stochastic sensor errors of the inertial measurement unit is presented. The identified parameters are used as a basis for the selection of the covariances. The overall study provides a practical implementation strategy and demonstrates its applicability in real-world scenarios. The experiments show the results of the lateral force estimation and its relation to the friction ellipse. The effectiveness of

Winkler, Alexander, Grabmair, Gernot, Reger, Johann

Prediction Method of Strength Robustness Affected by Arc Welding Sectional Dimensions

2024-32-003804/18/2025

The arc welding process is essential for motorcycle frames, which are difficult to form in one piece because of their complex shapes, because a single frame has dozens of joints. Many of the damaged parts of the frames under development are from welds. Predicting the strength of welds with high reliability is important to ensure that development proceeds without any rework. In developing frames, CAE is utilized to build up strength before prototyping. Detailed weld shapes are not applicable to FE models of frames because weld shapes vary widely depending on welding conditions. Even if CAE is performed on such an FE model and the evaluation criteria are satisfied, the model may fail in the actual vehicle, possibly due to the difference between CAE and actual weld bead geometry. Therefore, we decided to study the extent to which the stresses in the joint vary with the variation of the weld bead geometry. Morphing, a FE modeling method and design of experiment method, was utilized to

Hada, Yusuke, Sugita, Hisayuki

Research on Intake Sound Tuning Method by Valve Timing Modification for Enhance Sound Quality in V6 Outboard Engine

2024-32-005904/18/2025

This paper explores methods to enhance the sound quality of V6 outboard engines. Previous research in the boat and outboard engine domain has underscored the importance of enhancing sound quality. Specific preferences and desired directions for outboard engine sound quality have been identified. It’s been suggested that controlling intake sound and gear noise is important to achieving desired sound quality according to customer preferences. However, there are few examples of methods for achieving this. This study aims to develop methods for enhancing sound quality by emphasizing low-frequency sounds through intake sound. Initially, various methods were evaluated, and intake valve timing modification was chosen. Simple simulations confirmed that delaying valve timing for some cylinders may introduce characteristics that are not present in conventional cases. Subsequent 1D simulations identified optimal intake valve timing, balancing intake pressure characteristics and horsepower

Muramatsu, Hideta, Matsumoto, Taro, Naoe, Gaku, Kondo, Takashi

Detailed Approach for Pre-Chamber Heat Release Analysis for the HSASI Pre-Chamber Spark Plug Using a Pressure Sensor Glow Plug

2024-32-006304/18/2025

The hot surface-assisted spark ignition (HSASI) pre-chamber spark plug, which was developed at the Karlsruhe University of Applied Sciences, increases the dilution limit with excess air and the tolerance to residual gas in the pre-chamber compared to a conventional passive pre-chamber spark plug. In this study, the conventional glow plug which is integrated in the pre-chamber of the HSASI pre-chamber spark plug was replaced by a pressure sensor glow plug (PSG) from BERU. This allows for a detailed combustion analysis in the pre-chamber. The signal of the PSG was validated with a piezoelectric cylinder pressure sensor and a method to analyse the pre-chamber heat release was introduced. Experimental investigations were carried out on a single-cylinder gasoline engine. A series of operating points diluted with excess air and a variation in load were conducted. The gas flow rate through the orifices of the pre-chamber was calculated from the pressure difference between the pre-chamber and

Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland

Development of the Mild Hybrid System for Off-Road Machinery

2024-32-006704/18/2025

In recent years, the importance of achieving carbon neutrality has been highlighted in response to the escalating severity of climate change. In the leading automobile market, the share of electric vehicles is gradually expanding, especially in passenger car sector. However, it is not same in commercial vehicle sector. In the off-road machinery market, as with electrification in commercial vehicles, the factors such as the need to install charging infrastructure and the requirement for large batteries to expand operating duration are significant challenge to full electrification. As one of the realistic solutions toward carbon neutrality for off-road machines, methods to utilize both internal combustion engines (ICE) and their applied products are being reconsidered. Under the circumstances, we have developed a mild-hybrid (MH) system for small off-road machinery. This system adopts a 48V power supply in order to minimize size of the system offers as a “Drop-in” package solution. This

Koyama, Kazuaki, Kimura, Ryota, Nagamori, Yuko, Horita, Tatsuhiko, Nosaka, Kento

Traction Voltage Level in Two-Wheelers: Considerations on Safety and Performance

2024-32-006204/18/2025

Most electric 2-wheelers on the market today seek to replace combustion engine vehicles from 50cc to 150cc which equates to an electric motor power between 2 and 12 kW. The traction voltage level of these vehicles is mostly between 44V and 96V. However, the actual choice of voltage on a specific vehicle seems to be arbitrary and higher voltage does not necessarily correlate with higher motor power. This paper seeks to highlight considerations and tradeoffs which feed the choice of traction voltage levels. Important criteria are electrical safety standards and their impact on vehicle electrical architecture, the performance and availability of key electronics parts such as capacitors, MOSFETs, and gate drivers, while also highlighting functional safety aspects. This paper shows by a comprehensive analysis of the motor drive that for the vehicle class mentioned above the traction voltage level can be kept below 60V without any performance impact, while also ensuring electrical and

Schmitt, Stefan

Statistical Analysis of Data Acquired from Propagating Flames in Gasoline Engines Using a Multiple Ion Probe

2024-32-003504/18/2025

Multiple-ion-probe method consists of multiple ion probes placed on the combustion chamber wall, where each individual ion probe detects flame contact and records the time of contact. From the recorded data, it is also possible to indirectly visualize the inside of the combustion chamber, for example, as a motion animation of moving flame front. In this study, a thirty-two ion probes were used to record flames propagating in a two-stroke gasoline engine. The experiment recorded the combustion state in the engine for about 3 seconds under full load at about 6500 rpm, and about 300 cycles were recorded in one experiment. Twelve experiments were conducted under the same experimental conditions, and a total of 4,164 cycles of signal data were obtained in the twelve experiments. Two types of analysis were performed on this data: statistical analysis and machine learning analysis using a linear regression model. Statistical analysis calculated the average flame detection time and standard

Yatsufusa, Tomoaki, Okahira, Takehiro, Nagashige, Kohei

Study on Motorcycle Rider Model Using Reinforcement Learning - Learning Examples Including Following Target Velocity and Basic Research on Rider Proficiency

2024-32-002804/18/2025

In this study, an initial approach using deep reinforcement learning to replicate the complex behaviors of motorcycle riders was presented. Three learning examples were demonstrated: following a target velocity, maintaining stability at low speeds, and following a target trajectory. These examples serve as a starting point for further research. Additionally, the proficiency of the constructed models was examined using rider proficiency evaluation methods developed in previous studies. Initial results indicated that the models have the potential to mimic real rider behaviors; however, challenges such as differences between the model’s output and what humans can produce were also identified for future work.

Mitsuhashi, Yasuhiro, Momiyama, Yoshitaka, Yabe, Noboru

Representative Point of Measurement of Engine ECU and Effect of Vortices and Ambient Wall on Forced Air-Cooling

2024-32-003604/18/2025

The Electric Control Unit (ECU) is a crucial computing unit responsible for engine regulating various functions. However, non-airflow thermal design due to the complexity of engine bay turbulent flow simulation is limiting ECU’s potential with the increasing demand of computation power consumption, thermal design faced additional challenges. Moreover, the lack of standardized ECU design guidelines forced substantial investments in customized thermal solutions for different engine bay packaging. Through this research, the method of finding representative points of ambient temperature efficiently and reliably is investigated, so that thermal design can be achieved by estimating flow properties during the ECU design stage efficiently. This research involves studying the effects of airflow on ECU cooling using experimental and numerical analysis in Computational Fluid Dynamics (CFD). Alongside the representative points of ambient temperature uncovered from the numerical result

Zhong, Jiajun, Inaba, Kazuaki, Yamaguchi, Ryota, Yasui, Ryuta, Umeno, Masafumi

Development of Pistons Suitable for Compact Air-Cooled Engines

2024-32-003004/18/2025

For the realization of carbon neutrality, we are working on research to improve the thermal efficiency of engines for motorcycles. Friction losses in the cylinder bore account for about 40% of the total friction losses of the engine (Figure 1), which is directly related to thermal efficiency improvement [1]. Air-cooled engines are suitable for motorcycles due to their simplicity and light weight, but it is difficult to achieve both efficiency and reliability. Friction in the cylinder is generated by piston scuffing. The oil film distribution of the piston-skirt(=skirt) is thin at the center of the skirt and thick at the edge. To reduce piston friction, it is effective to make the thin oil film at the center of the skirt thicker. On the other hand, to reduce oil consumption, the oil film must be thinned. However, air-cooled engines, which are difficult to keep the cylinder temperature constant, cannot make the clearance between the cylinder bore and the piston small. An increase in

Suda, Naoyuki, Hihara, Taiki, Ninomiya, Yoshinari

Experimental Investigation of n-C7H16/Ethanol Blended Fuels on Auto-ignition and Flame Propagation in High Temperature/Pressure Constant-Volume Combustion Vessel

2024-32-005004/18/2025

This study aims to investigate the effect of ethanol blends on flame propagation and auto-ignition under high pressure and high temperature conditions. Experimental investigations are conducted using n-C7H16 / ethanol blends at various blending ratios (0, 5, 10, 20, 40, 70, and 100 vol%). The blends are premixed with air at stoichiometric ratios and ignited centrally in a cylindrical constant-volume combustion chamber (20-mm inner diameter, 80-mm long) under elevated temperature (500 K) and pressure (1.0 MPa) conditions. The results show that auto-ignition occurs at an ethanol blend ratio of 10% or less and ceases above 20%. Increasing the ethanol blend to 70% results in a slight change in flame propagation speed, with a noticeable delay at 100%. The pressure measurements show a peak of about 5.6 MPa at a blend ratio of 5%, which gradually decreases with increasing ratios. High-pass filtering reveals the maximum pressure fluctuation amplitude at the 5% blend ratio, indicating increased

Tateishi, Tokua, Yamaguchi, Riki, Shimokuri, Daisuke, Terashima, Hiroshi, Hara, Takaya, Honda, Yuya, Kawano, Michiharu

Enhancing Low Temperature Lean Combustion of CH4-H2 Blends through a Prechamber Equipped Engine

2024-32-004404/18/2025

The use of hydrogen as a sustainable fuel in the short term is hampered by the impossibility of large scale use due low availability. In order to promote decarbonization, complementary solution for a smooth transition is to dilute it in a mixture with methane, in a current Port Fuel Injection (PFI) internal combustion engine (ICE). This can be done as a retrofit after limited structural modifications, such as the introduction of a passive prechamber. Such a solution allows a reduction of the carbon footprint of traditional ICEs through more efficient combustion (both the prechamber technology and the hydrogen fuel properties promote an increase in combustion speed) and a reduced carbon content in the fuel. The present research activity has been carried out through numerical investigation based on three-dimensional CFD analyses to simulate the behavior of a natural gas engine fueled with CH4-H2 blends. The combustion mechanism for the fuel blend was validated against measurements of the

Balduzzi, Francesco, Ferrara, Giovanni, Di Iorio, Silvana, Sementa, Paolo

Experimental Study of Port Water Injection System on Single Cylinder Diesel Engine Performance and Exhaust Emission

2024-32-002504/18/2025

Vehicle emission standards have become more and more stringent and have driven the development of advanced engine design with low-cost emission control technologies. For small diesel engine which is used in three-wheel (3W) passenger and load carrying vehicles, it was major task to improve lower engine rpm torque and performance to comply with stringent exhaust emissions standard as well, especially for Oxides of Nitrogen (NOx) and Particulate Matter (PM) emissions. Bharat Stage (BS) VI emission standards for three-wheel vehicles was implemented from April 2020 onwards in India. Water injection technology has proven advantageous for low-cost solution with Mechanical fuel injection system on small diesel engines, Intake port water injection is the easiest method to introduce water to engine cylinder, which calls for minimal modification of existing engine structure. In the present study 435cc naturally aspirated DI Diesel engine used for three-wheel vehicle was explored by adding water

Syed, Kaleemuddin, Chaudhari, Sandip, Khairnar, Girish, Katariya, Rahul, Jagtap, Pranjal, Bhoite, Vikram

Analysis of the Effect of Combination Frame Flexibility on Weave Modes

2024-32-004904/18/2025

The weave mode of a motorcycle is known to be affected by the flexibility of the vehicle frame. The weave mode has been shown to be more unstable in the 10-DOF model than in the 4-DOF model. However, it is not clear why the weave mode would be unstable, given the six different frame flexibilities. In this study, the authors analyzed the stability of the weave mode in a 4-DOF model when the same was integrated with two types of frame flexibilities. In the vehicle specifications used in the analysis, the combination of the bending flexibility of the front forks and the torsional flexibility of the main frame destabilizes the weave mode. The analysis results show that the phase delay of the front tire lateral force is caused by the phase delay of the steering angle. The combined bending flexibility of the front forks and the torsional flexibility of the main frame results in a large phase lag in the steering angle.

Haraoka, Reiya, Katayama, Tsuyoshi, Yoshino, Takahiko

Operating Characteristics of an Automotive Adjustable-Field Permanent Magnet Motors with 3D Magnetic Paths and Asymmetric Magnet Arrangement

2024-32-002704/18/2025

This paper describes a three-dimensional structure of an adjustable field magnetization permanent magnet (PM) motor and a high-power density rotor structure with asymmetric permanent magnet arrangement for both high torque and high efficiency operation in the high speed and low torque range. 3D-FEA has confirmed that it is possible to achieve both high torque density and adjustable field magnetization. Load testing using the prototype proposed motor confirmed that high motor efficiency can be achieved even during high-speed operation.

Hiyoshi, Yutaro, Doi, Kotaro, Noguchi, Toshihiko

Effect of Mesopore Structure of Carbon Gel on Improving the Capacity of Electric Double-Layer Capacitors

2024-32-002604/18/2025

Electric double-layer capacitors (EDLCs) store charge by adsorbing ions at the electrode-electrolyte interface, offering fast charge/discharge rates, high power density, minimal heat generation, and long cycle life. These characteristics make EDLCs ideal for memory backup in electronic devices and power assistance in electric and hybrid vehicles. However, their energy density is lower than that of batteries, necessitating improvements in electrical capacity and potential. Traditionally, activated carbon with a high specific surface area has been used, but recent research focuses on mesoporous carbon materials for better ion diffusion. This study uses resorcinol-formaldehyde-carbon cryogel (RFCC) with mesopores and organic electrolytes with a wider electrochemical window. Various RFCCs with different pore sizes were synthesized and evaluated. Comprehensive investigations into the pore structures and surface properties of both synthesized carbon gels and commercial mesoporous materials

Cheng, Zairan, Okamura, Tsubasa, Ohnishi, Yuto, Nakagawa, Kiyoharu

A Power Split eCVT Hybrid for Sustainable Urban Mobility

2024-32-002904/18/2025

The main drivers for powertrain electrification of two-wheelers, motorcycles and ATVs are increasingly stringent emission and noise limitations as well as the upcoming demand for carbon neutrality. Two-wheeler applications face significantly different constraints, such as packaging and mass targets, limited charging infrastructure in urban areas and demanding cost targets. Battery electric two wheelers are the optimal choice for transient city driving with limited range requirements. Hybridization provides considerable advantages and extended operation limits. Beside efficiency improvement, silent and zero emission modes with solutions allowing fully electric driving, combined boosting enhances performance and transient response. In general, there are two different two-wheeler base categories for hybrid powertrains: motorcycles featuring frame-integrated internal combustion engine (ICE) and transmission units, coupled with secondary drives via chain or belt; and scooters equipped with

Schoeffmann, W., Fuckar, G., Hubmann, C., Gruber, M.

Model-Based Calibration of ECU for Small Motorcycles

2024-32-002404/18/2025

To deal with the emission regulations it is necessary to produce ECU control maps that maintain balance of emissions of HC, NOX, CO, engine power output and fuel consumption during the motorcycle development. We have recently introduced the Model-Based Calibration (hereafter as MBC) for calibration of ECU control maps for small motorcycles, which share a big chunk of the market. When introducing we aimed at such a method that can simulate stable temperature conditions necessary for the measurement in order to make it applicable to air-cooled engines predominantly used in small motorcycles. To decrease performance difference between the prototype and the mass-production, the newly developed method allows rewriting of control parameters such as the ignition timing using the mass-production ECU. The fully automated data acquisition along with the application of MBC permits continuous test operations even in nighttime and on holidays. Moreover, the MBC flow was made such a manner that

Fujiwara, Hirofumi, Maruyama, Atsushi, Kasai, Yoshiyuki

Investigation on Degradation Process of PdRuIr/CZ “Pseudo-Rh” Catalysts Used for Motorcycles

2024-32-001604/18/2025

Platinum (Pt), palladium (Pd), and rhodium (Rh) are used as active substances in exhaust gas purification catalysts for automobiles. Among these, Rh is an essential element because it efficiently promotes a NOx reduction reaction. On the other hand, the price of Rh has been rising in recent years. From the perspective of the supply risk of rare resources, there is an urgent need to develop technologies to replace or reduce the amount of Rh used in catalysts. We focused on the pseudo-rhodium alloy developed by the ACCEL program of the Japan Science and Technology Agency (JST), and then investigated the application of the pseudo-rhodium alloy on the catalysts of our motorcycles and also the degradation process. A nanosized PdRuIr alloy supported on a ceria-zirconia solid solution (PdRuIr/CZ) was prepared and assembled into a motorcycle for emissions measurement. The PdRuIr/CZ catalyst with an alloy loading of 4.0 g/L had initial properties comparable to the Rh supported on a CZ (Rh/CZ

Motegi, Takuya, Tatara, Shunya, Takamoto, Shunpei, Doi, Kosuke

A Concept for Functional Modelling of an E-Bike Powertrain

2024-32-001704/18/2025

The increasing popularity of e-bikes, especially pedelecs, has led to a growing interest in consideration of e-bike cycling. To achieve a deeper understanding on the process of e-bike cycling and in particular the effects on the rider it can be instrumental to use simulation methods. In this context, the e-bike drive system and its function are of central importance for e-bikes. Therefore, this work proposes a functional modeling of the powertrain of an e-bike with a mid-drive motor, considering legal constraints and support functionalities. The model incorporates the mechanical transmission between pedals, motor, and crank shaft, allowing for a detailed analysis of the e-bike’s performance. Additionally, the support mechanism is depicted, where an electric motor amplifies the rider’s pedaling torque. The electrical behavior of the motor, energy consumption, and battery state of charge are also integrated into the model. This comprehensive approach aims to provide a generic

Rauch, Yannick, Kettner, Maurice, Kriesten, Reiner

Impacts of Pulsating Flow on Topologically Optimized Porous Reactors in Convection-Diffusion-Reaction Systems

2024-32-007004/18/2025

Topology optimization (TO) in electrochemical systems has recently attracted many researchers. Previous studies suggested minimal performance differences between 2D and 3D designs, indicating that 2D models suffice to enhance performance, especially in unidirectional flow scenarios. A later study found that the concentration distribution in an optimized 2D flow system differed from that in a unidirectional flow system. We posited that pulsating flow could further enhance the performance of such systems. First, we initiated TO for a diffusion-reaction system in a steady state. The optimized structure obtained from this process served as the foundation for subsequent investigations involving a pulsating flow source in convection-diffusion-reaction systems. We introduced two different systems with distinct flow natures: one characterized by a flow nature of 1D and the other by a flow nature of 2D. The results demonstrated that the optimized structure with a heterogeneous distribution

Long, Mengly, Alizadeh, Mehrzad, Sun, Pengfei, Charoen-amornkitt, Patcharawat, Suzuki, Takahiro, Tsushima, Shohji

Enhancements in Hydrogen Low Pressure Injection on Small Two-Stroke Engines

2024-32-004704/18/2025

The use of small 2-stroke crankcase scavenged engines running on hydrogen is very attractive for low power rates, when low cost and compact dimensions are the fundamental design constraints. However, achieving optimal performance with hydrogen fuel presents challenges, including uneven air-fuel mixtures, fuel losses, and crankcase backfiring. This research focuses on a small 50cc 2-stroke loop-scavenged engine equipped with a patented Low-Pressure Direct Injection (LPDI) system, modified for hydrogen use. Experimental results demonstrate performance comparable to the gasoline counterpart, but further optimizations are needed. Consequently, CFD-3D simulations are employed to analyses the injection process and guide engine development. The numerical analysis focuses on a fixed operating condition: 6000 rpm, Wide Open Throttle (WOT), with a slightly lean mixture and injection pressure fixed at 5 bar. A numerical model of the entire engine is set up with the primary objective of improving

Caprioli, Stefano, Schoegl, Oliver, Oswald, Roland, Kirchberger, Roland, Mattarelli, Enrico, Rinaldini, Carlo Alberto

Basic Investigation of Thermodynamic Effects on a Hydrogen Two-Stroke Engine

2024-32-003904/18/2025

The spark ignited two-stroke engine, as a cost-efficient power unit with low maintenance demand, is used millionfold for the propulsion of hand-held application, motorcycles, scooters, boats and others. The outstanding power to weight ratio is the key advantage for two-stroke engines. However, poor exhaust emissions, caused by high scavenge losses, especially on port controlled two-stroke engines, and a low efficiency are disadvantages of this combustion process. Under the aspect of increasing environment- and health awareness, the two-stroke technology driven with fossil resources, shows no future advantage. The anthropogenic climate change force for sustainable development of combustion engines whereby reduction of fuel consumption or usage of alternative fuels is an important factor. Best way of a decarbonization to fulfil future climate goals is the utilization of non-carbon fuels. In this field of fuels, hydrogen, with its high energy content and close inexhaustible availability

Yasuda, Terutaka, Oswald, Roland, Kirchberger, Roland

Analysis of Lane Departure Caused by Inadequate Motorcycle Driving Maneuvers Due to Road Alignment

2024-32-003404/18/2025

There are many riders who drive motorcycles on winding mountain roads and caused single motorcycle traffic accidents on curved roads by lane departure. Driving a motorcycle requires subtle balancing and maneuvering. In this study, in order to clarify the influence of lane departure caused by inadequate driving maneuvers against road alignment, the authors analyzed the required curve initial operation and driving maneuvers in curves depending on the traveling speed using a kinematics simulation for motorcycle dynamics. In addition, it was analyzed how inadequate driving maneuvers for curved roads can easily cause lane departure. As a result, it shows that the steering maneuvers and the lean of motorcycle body during the curves are highly affected by the vehicle speed, and the required maneuvers increases rapidly with increasing speed. The inadequate maneuver in the curves, especially for the lean of motorcycle body and steering torque, even by 10%, may cause failure to follow the

Kuniyuki, Hiroshi, Takechi, So

Development of Higher Clarity Injection Molded Windscreen for Motorcycles

2024-32-004004/18/2025

The windscreen is one of the key elements to enhance passenger comfort of touring motorcycle. The clarity through the windscreen should not discomfort the rider. The discomfort we discuss here mainly refers to three factors: the “distortion,” the “blur,” and the “transparency.” Introduced in this paper is the technical measures to achieve sufficient clarity by the injection molding method. Firstly, with respect to the “distortion,” we determined the main cause was local unevenness of plate thickness. As the uneven thickness were related to the accuracy of the die, we clarified the tolerable zone and carried out higher precision machining of the die to satisfy the requirements. Regarding the “blur,” we analyzed the refractive power of the windscreen and found the main cause of blur is the microscopic roughness on the surface. As the microscopic roughness were attributable to the die surface, we clarified the tolerable zone and established the polishing conditions satisfactory for the

Yamada, Atsushi, Endo, Sakae

Studying the Lean Burn Operation in Two-Wheelers to Increase Fuel Efficiency and Investigate the Use of Lean NOx Trap Catalyst (LNT) for Lean Burn System

2024-32-005804/18/2025

This study offers an overview of the impact of lean burn technology in two-wheeler vehicles, specifically concentrating on enhancing the fuel economy and addressing the challenges associated with its adoption. Lean burn systems, characterized by a fuel-air mixture with a higher air content than stoichiometric ratio. The study focuses on technology which meets stringent emission standards while enabling the optimization of fuel efficiency. The lean burn system employs strategies to optimize air-fuel ratio using electronic fuel injection, ignition timing control, and advanced engine control algorithms like - updated torque modulation control algorithm for drivability, lambda control algorithm for rich and lean switch and NOx modelling algorithm for LNT catalyst efficiency tracking. The challenges related to lean burn systems, includes issues related to combustion stability, nitrogen oxide (NOx) emissions, and their impact on drivability, is summarized in the study. Mitigation strategies

Somasundaram, Karthikeyan, Sivaji, Purushothaman, John Derin, C, Vishal, Karwa, Manoj Kumar, S, Maynal, Rajesh

Experimental Investigations of a Hydrogen Fueled Natural Gas Engine and Ion Current Measurement for Combustion Diagnostics in Pure Hydrogen Operationwith Water Injection

2024-32-006504/18/2025

In the ongoing effort to decarbonize energy supply, a notable shift involves the conversion or retrofitting of combined heat and power plants to operate on hydrogen as an alternative to natural gas. In this transformative landscape, extensive research is underway to develop and explore innovative combustion processes for hydrogen-fueled engines, aiming to comprehend and optimize combustion processes concerning both engine performance and emissions. Among the various methods available for monitoring the combustion process and engine control, ion current sensing presents itself as a viable option. A unique feature of this research lies in utilizing the engine's spark plug itself as an electrical sensor, measuring the ion current generated during the flame development and combustion processes. Given the limited research on ion current sensing for hydrogen combustion processes, a series of experiments were conducted and presented in this work. These experiments involved sweeps of water-to

Salim, Naqib, Beltaifa, Youssef, Kettner, Maurice, Loose, Oliver, Weißgerber, Tycho

Impact of Ordinal Proximity of Frequency Components on the Auditory Perception of Engine Knocking

2024-32-003204/18/2025

This study examines the acoustic properties of engine-knocking sounds in gasoline engines, arising from misfires during spark ignition that negatively affect driving performance. The aim was to understand the frequency characteristics of acceleration sounds and their connection to the proximity of the order components. The study also explores “booming,” where two different frequencies of sounds occur simultaneously, potentially linked to the unpleasant nature of engine knocking. Using a sinusoidal model, we generated engine acceleration sound models with 5th-, 10th-, and 15th-order components, including engine knocking. Two types of sound stimuli were created: one with the original amplitude (OA) and one with a constant amplitude (CA) for each component order, emphasizing the order-component proximity in CA sounds. Aural experiments with 10 participants in an anechoic room using headphones and the MUSHRA method revealed an inverse relationship between OA and CA ratings as the component

Suzuki, Ryuhei, Ishimitsu, Shunsuke, Nitta, Misaki, Sakakibara, Mika, Hakozaki, Tomoyuki, Fujikawa, Satoshi, Iwata, Kiyoaki, Matsumoto, Mitsunori, Kikuchi, Masakazu

Investigation on the Applicability of Passive Type Pre-Chamber with One Port Fuel Injection System to Small Gasoline Engines

2024-32-003304/18/2025

Pre-chamber combustion has been applied as a method of low fuel consumption in spark ignition engines, and in recent years the application of pre-chambers to gasoline engines has also been actively studied. In many gasoline engines, stoichiometric combustion is common. We decided that a passive type pre-chamber with only one port fuel injection is sufficient for stoichiometric combustion. The pre-chamber system relatively has two merits of lower cost and ease of installing than other prechamber systems. Therefore, we focused on investigating the effects of improving combustion speed and knock resistance in use of the passive type pre-chamber and the applicability of the pre-chamber system in various operating points. As the concrete approach, we evaluated the heat balance and the knock resistance with and without a pre-chamber in engine bench test. As a result, the knock resistance and the fuel consumption were improved. In addition, as a result of considering lean burn in the passive

Nakao, Yoshinori, Sakurai, Yota, Hisano, Atsushi, Saitou, Masahito, Suzuki, Tomoharu

DoE-Based Numerical Optimization of Intake and Exhaust Port Geometry of a Small Opposed-Piston 2-Stroke (OP2S) Hydrogen Engine

2024-32-005404/18/2025

The future potential of an opposed-piston two-stroke (OP2S) engine has attracted the attention of researchers worldwide as it offers a high thermal efficiency and power-to-weight ratio with a simple engine configuration. This engine can be used with low-carbon fuels and hydrogen to reduce greenhouse gas emissions. However, the two-stroke operation has always been limited by its low scavenging efficiency and short-circuit of fresh charge. The current work is focused on optimizing scavenging efficiency and short-circuit in a small 200 cc single-cylinder OP2S SI engine using 3-D computational fluid dynamic (CFD) simulations. The effect of four parameters, namely, area of intake ports, area of exhaust ports, and angular orientations of intake ports (swirl and tilt) on scavenging efficiency and short-circuit, has been assessed and optimized. A Latin-hypercube based Design of Experiments (DoE) methodology is used to sample the design space spanning over a range of four parameters. A response

Singh, Saurabh, Boggavarapu, Prasad, Himabindu, M., Ravikrishna, R.V.

Predictive Battery Thermal Management System Control Strategy and Simulation in Electric Vehicle

2025-01-502704/03/2025

With the global issue of fossil fuel scarcity and the greenhouse effect, interest in electric vehicles (EVs) has surged recently. At that stage, because of the constraints of the energy density and battery performance degradation in low-temperature conditions, the mileage of EVs has been criticized. To guarantee battery performance, a battery thermal management system (BTMS) is applied to ensure battery operates in a suitable temperature range. Currently, in the industry, a settled temperature interval is set as criteria of positive thermal management activation, which is robust but leads to energy waste. BTMS has a kilowatt-level power usage under high- and low-temperature environments. Optimizing the BTMS control strategy becomes a potential solution to reduce energy consumption and overcome mileage issues. An appropriate system simulation model provides an effective tool to evaluate different BTMS control strategies. In this study, a predictive BTMS control strategy, which adjusts

Huang, Zhipei, Chen, Jiangbo, Tang, Hai

Optimization of the Numerical Spray Modeling for Polyoxymethylene Dimethyl Ethers for Combustion Prediction in CONVERGE

2025-01-502604/03/2025

Different approaches are undertaken to mitigate the impact of the transport sector on climate change. Alongside electrifying powertrains, sustainable e-fuels such as polyoxymethylene dimethyl ethers (OME) are considered a promising bridging technology for different applications. However, this requires that the engines are optimized for the new fuels. Accordingly, this study aims to optimize the numerical spray modeling of OME in CONVERGE. Based on the KH–RT break-up model, the spray simulations of three different commercial injectors for heavy-duty applications are analyzed regarding the predictability of the liquid and gaseous penetration lengths and the total simulation time. A sensitivity analysis is conducted for the turbulence model, mesh size, and spray parameters prior to optimizing the spray model and validating it with experimental results. While each parameter individually influences the different phases of the injection event, the sensitivity analysis reveals that the break

Zepf, Andreas, Härtl, Martin, Jaensch, Malte

Mechanical Property Analysis of Triply Periodic Minimal Surface Structure with a Novel Hybrid Structure

2025-01-8215

04/03/2025

Abstract Triply periodic minimal surface (TPMS) structure, demonstrates significant advantages in vehicle design due to its excellent lightweight characteristics and mechanical properties. To enhance the mechanical properties of TPMS structures, this study proposes a novel hybrid TPMS structure by combining Primitive and Gyroid structures using level set equations. Following this, samples were fabricated using selective laser sintering (SLS). Finite element models for compression simulation were constructed by employing different meshing strategies to compare the accuracy and simulation efficiency. Subsequently, the mechanical properties of different configurations were comprehensively investigated through uniaxial compression testing and finite element analysis (FEA). The findings indicate a good agreement between the experimental and simulation results, demonstrating the validity and accuracy of the simulation model. For TPMS structures with a relative density of 30%, meshing with

Tang, Haiyuan, Xu, Dexing, Sun, Xiaowang, Wang, Xianhui, Wang, Liangmo, Wang, Tao

A review of warm forming for steels: History, Methodology and Emerging trends

2025-01-881404/01/2025

Many manufacturing techniques and process modifications have been implemented over the years to improve the formability of sheet metals. Warm forming of sheet metals is one such established method. However, it is more commonly and successfully applied to aluminum grades. The reevaluation of less-used metal forming technologies, such as warm forming and sheet hydroforming for steel, is a response to the challenges posed by competitive processes like large castings and the geometry requirements of new BEV parts. By understanding the effects of elevated temperatures (below recrystallization temperatures) on different steel grades and the impact of various heating methodologies, the industry can adapt and optimize these proven techniques for modern applications. This paper is a comprehensive summary of the effect of elevated temperatures on various grades of steel. Different heating techniques, their cycle times and effects on final forming feasibility is contrasted. The effect of

Kella, Caroline, Wormald, Tom, Gatts, Joshua

Calculation of Airflow through the Air Cycle Technology’s Turboexpander and Its Effects on a Diesel Engine—Part I

2025-01-502303/31/2025

Amidst escalating climate change, the sustainability of internal combustion engine (ICE) vehicles, particularly in heavy transport, remains a critical challenge. Despite emission reductions from 1990 to 2020, ICEs, particularly diesel engines in Europe, continue to pose environmental challenges, notably in nitrogen oxide (NOx) emissions. This study proposes a novel solution to address the problem of NOx emissions by incorporating Air Cycle Technology’s (ACT) turboexpander into diesel engines. Acting as a second-stage compressor, intercooler, and expander, the turboexpander aims to lower intake air temperature, thereby mitigating NOx formation. The study utilizes a 4.4-l JCB-TCA-74 turbocharged diesel engine retrofitted with the ACT turboexpander as the experimental platform. The methodology involves using empirical formulae to calculate the key parameters of engine airflow for a standard turbocharged diesel engine followed by repeating the calculations for the same engine fitted with a

Fayaz, Farheen, Brace, Jordan, Allport, John, Javanbakht, Gina

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