The objective of this experimental study was to investigate the change of shifting rate of metal V-belt type CVT during speed up/down under quasi-idle loading condition. Changes in the rotational speeds of the driving and driven pulleys were simultaneously measured by the rotational speed sensors installed on the driving and driven shafts during speed up/down shifting, respectively. In addition, the interaxial force applied to the driving and driven pulleys was measured by a load cell. The shifting rate was defined as the ratio of the calculated radial displacement to the tangential displacement of the belt in the pulley groove. This study found that the shifting rate was determined not only by the slippage between the pulley and the belt element, but also by the elastic deformation of the belt element in the pulley groove. The power transmission performance was improved when the elastic deformation was small even though radial slippage between the pulley and the belt element was

Mori, Yuichirou, Okubo, Kazuya, Obunai, Kiyotaka

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

2024-32-0070

To be published on 04/18/2025

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

A Study on Optimal Combinations of Winding and Cooling Methods for Downsizing Power Units in Motorcycles

2024-32-0007

To be published on 04/18/2025

In commercially available electric motorcycles, there is a notable shift in the cooling method, moving from air cooling to water cooling, and in the winding method, moving from concentrated winding to distributed winding, as the output increases. This shift occurs around 8 to 10 kW. However, there is a paucity of empirical investigations examining these combinations to ascertain their optimality. In order to verify this trend, a verification model has been constructed which allows for the comparison of the capacity and weight of the motor and cooling system according to the vehicle’s required output and thermal performance. A comparison and verification of the combinations of winding methods (concentrated winding or segment conductor distribution winding) and cooling systems (water-cooled or air-cooled) was conducted using the model that had been constructed. In the motor designed for this study, when the maximum output of the vehicle was 35 kW or less (European A2 license), the total

Otaki, Ryota, Tsuchiya, Teruyuki, Sakai, Yu, Yamauchi, Takuya, Shimizu, Tsukasa

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

2024-32-0028

To be published on 04/18/2025

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

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

2024-32-0035

To be published on 04/18/2025

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

A Methodical Concept Study and Optimization of the Drivetrain for Light Commercial Vehicle Applications

2024-32-0115

To be published on 04/18/2025

The EU currently has very ambitious plans for the electrification of vehicles, particularly in the field of urban logistics. For example, the so-called “Transport White Paper” [1] aims to achieve essentially CO2-free logistics in major urban centers by 2030, while “Europe on the move” [2] has presented a series of legislative initiatives. The Strategic Research and Innovation Agenda for Transport proposes research priorities and actions to deploy innovative solutions, with a particular focus on the electrification of transport. Numerous advancements in electromobility have led to a growing number of vehicles available in various areas, particularly in urban logistics. New concepts like cargo bikes and micro-vehicles are being developed, but they cannot fully replace traditional light commercial vehicles. While some electrified options exist, they are often modified versions of existing platforms with internal combustion engines swapped for electric drives. The research work in this

Königshofer, Thomas, Tromayer, Jürgen, Schacht, Hans-Jürgen, Wang, Eric

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

2024-32-0013

To be published on 04/18/2025

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

Dynamic Nonlinear Viscoelastic Measurements of Vehicle Seat Components for Ride Comfort Evaluation

2024-32-0051

To be published on 04/18/2025

Ride comfort is an important factor in the development of vehicles. Understanding the characteristics of seat components allows more accurate analysis of ride comfort. This study focuses on urethane foam, which is commonly used in vehicle seats. Soft materials such as urethane foam have both elastic and viscous properties that vary with frequency and temperature. Dynamic viscoelastic measurements are effective for investigating the vibrational characteristics of such materials. Although there have been many studies on the viscoelastic properties of urethane foam, no prior research has focused on dynamic viscoelastic measurements during compression to simulate the condition of a person sitting on a seat. In this study, dynamic viscoelastic measurements were performed on compressed urethane foam. Moreover, measurements were conducted at low temperatures, and a master curve using the Williams–Landel–Ferry (WLF) formula (temperature–frequency conversion law) was created.

Kamio, Chihiro, Yamaguchi, Takao, Maruyama, Shinichi, Hanawa, Kazuto, Iwase, Tsutomu, Hayashi, Tatsuo, Sato, Toshiharu, Mogawa, Hajime

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

2024-32-0059

To be published on 04/18/2025

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

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

2024-32-0066

To be published on 04/18/2025

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

Fatigue Analysis of Motorcycle Rear Swing Arm on Different Road Surfaces

2024-32-0046

To be published on 04/18/2025

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

Trends in the Automated and AutomaticTransmission Systems for Two Wheeled Vehicles

2024-32-0061

To be published on 04/18/2025

The two-wheeler industry features a diverse range of transmission systems catering to varied riding preferences and market demands. Manual transmissions offer direct gear control, favored by enthusiasts for its precision and customizable performance. Automatic transmissions simplify riding, especially in urban settings, eliminating manual gear shifts and reducing rider fatigue. Understanding the dynamics of transmission systems in the two-wheeler space is crucial for manufacturers, engineers, policymakers, and riders alike. It informs product development, regulatory compliance efforts, and market positioning initiatives in an increasingly competitive and innovation-driven industry landscape. DCT (Dual Clutch Transmission) and manual transmissions represent extremes in rider engagement, automation, and cost. While DCT offers seamless gear changes and convenience at a higher price point, manual transmissions provide direct control and a tactile experience with lower initial costs. Riders

Kundu, Prantik

Numerical Studies on the Relation between the Multiple Auto-Ignition and Pressure Wave in the Premixed Charge

2024-32-0079

To be published on 04/18/2025

The relation between the multiple auto-ignition in the premixed charge with fuel concentration distribution and associated pressure wave are numerically investigated. This study assumes that the auto-ignition phenomenon in the end-gas of PCCI combustion, a next-generation combustion method which is expected to achieve both low fuel consumption and low emissions at a high level. Detailed numerical analysis considering the elementary chemical reactions of the compressible reacting fluid flow described in the one-dimensional coordinate system with high spatial and time resolution was performed to clarify the detailed phenomena of the onset of the multiple auto-ignition and the pressure wave propagation in the gas.

Iizumi, Kota, Yoshida, Kenji

Experimental Study on Thermo-Catalytic Ammonia Decomposition into Hydrogen

2024-32-0118

To be published on 04/18/2025

In order to rapidly achieve the goal of global net-zero carbon emissions, ammonia (NH3) has been deemed as a potential alternative fuel, and reforming partial ammonia to hydrogen using engine exhaust waste heat is a promising technology which can improve the combustion performance and reduce the emission of ammonia-fueled engines. However, so far, comprehensive research on the correlation between the reforming characteristic for accessible engineering applications of ammonia catalytic decomposition is not abundant. Moreover, relevant experimental studies are far from sufficient. In this paper, we conducted the experiments of catalytic decomposition of ammonia into hydrogen based on a fixed-bed reactor with Ru-Al2O3 catalysts to study the effects of reaction temperature, gas hour space velocity (GHSV) and reaction pressure on the decomposition characteristics. At the same time, energy flow analysis was carried out to explore the effects of various reaction conditions on system

Li, Ze, Li, Tie, Chen, Run, Li, Shiyan, Zhou, Xinyi, Wang, Ning

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

2024-32-0032

To be published on 04/18/2025

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

Sustainable Design of Automotive Batteries

2025-01-0001To be published on 04/18/2025

A consequence of the automotive industry's shift to electrification is that a significantly higher percentage of a vehicle's lifecycle CO₂ emissions occur during the production phase. As a result, vehicle manufacturers and suppliers must shift the focus of product development from the 'in-use phase only' to optimizing the complete product lifecycle. The proper design of a battery has the highest impact to all other phases following in the life-cycle. It influences the selection of materials, the manufacturing, in-use and end of life, respectively the recycling and recycling yield for a circular economy. Using real-life examples the paper will explain what are the main parameters necessary for designing a sustainable battery. What are the low hanging fruits to be considered? In addition, it will elaborate on the relation as well as the impacts to other KPIs like safety, costs and life-time of the battery. Finally it will round up in an outlook on how batteries will evolve in the future

Braun, Andreas, Rothbart, Martin

On the Application of Trapped Vortices in Motorsport Application for Improved Aerodynamic Performance Using Passive and Active Flow Controls

2025-01-5029

To be published on 04/15/2025

New regulations introduced by the Fédération Internationale de l’Automobile (FIA) for the 2026 Formula 1 season mark the first instance of active flow control methods being endorsed in Formula 1 competition. While active methods have demonstrated significant success in airfoil development, their broader application to grounded vehicle aerodynamics remains unexplored. This research investigates the effectiveness of trapped vortex cavity (TVC) technology in both active and passive flow controls, applied to a NACA0012 airfoil and an inverted three-element airfoil from a Formula 1 model. The investigation is conducted using numerical methods to evaluate the aerodynamic performance and potential of TVC in this paper. In the single-airfoil case, a circular cavity is placed along the trailing edge (TE) on the suction surface; for the three-element airfoils, the cavity is positioned on each airfoil to determine the optimum location. The results show that the presence of a cavity, particularly

Ng, Ming Kin, Teschner, Tom-Robin

Experimental and Kinetic-Modeling Study of Ammonia/n-Heptane Combustion

13-06-03-0020

04/09/2025

In recent years, researchers have increasingly focused on ammonia–diesel dual-fuel engines as a means of reducing CO2 emissions. Analyzing in-cylinder combustion processes is essential for optimizing the performance of ammonia–diesel dual-fuel engines. However, there is currently a lack of suitable reaction kinetics models for ammonia–diesel engine conditions. In this study, the ignition delay of ammonia/n-heptane mixtures was measured, and a reduced chemical mechanism was developed. Using rapid compression machine (RCM) experiments, the ignition delays of ammonia/n-heptane mixtures with different ammonia energy fractions (AEFs) (40%, 60%, and 80%) were measured. The test pressure ranged from 1.5 to 3.0 MPa, while the temperature ranged from 667 to 919 K, with an equivalence ratio of 1. The results showed that as the AEFs increased, the ignition delay of the premixed mixture also increased. When the AEF was 40%, the ammonia/n-heptane premixed mixture exhibited the negative temperature

Cai, Kaiyuan, Liu, Yi, Chen, Qingchu, Qi, Yunliang, Li, Li, Wang, Zhi

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