Browse Topic: Power and Propulsion

Items (52,121)

060002To be published on 01/01/2099

Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement

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

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

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

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

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

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

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

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

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

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.

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

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

Optimizing Cooling Circuit Lines in between Batteries and Its Thermal Management Unit

2025-01-501703/21/2025

Ensuring uniform coolant distribution in electric buses is crucial for battery performance, longevity, and thermal stability. This study optimizes the battery thermal management system (BTMS) for an 18-m electric bus, addressing uneven coolant flow to battery packs caused by pressure drop variations. One-dimensional (1D) simulations were chosen for their ability to quickly and efficiently analyze flow and pressure variations, providing a fast solution to optimize coolant distribution across the system. dP-Q curves for the BTMS pump and battery packs were integrated into the 1D model based on supplier data, while the flow resistances of other components (pipes, bends) were calculated using KULI software. To correct flow imbalances, pipe diameters were adjusted to increase resistance in over-cooled areas, redistributing coolant to under-cooled sections. This modification resulted in a balanced flow and improved thermal consistency, contributing to longer battery life. Validation showed

Birgül, Çağrı Emre, Meydan, Ömer

Mitigating Carbon Dioxide Emissions in Diesel Engines through the Application of Physical Adsorbents

2025-01-500802/13/2025

Graphical Abstract Abstract The world is targeting zero-emission standards by promoting flexi-fuel-based vehicles. In the automotive industry, IC engine-powered vehicle has a good market. Either IC or flexi-fuel engines are considered the safest mode of transport, one tedious problem needs to be addressed is their toxic exhaust emissions from those engines. However, there are many aftertreatment systems available to control HC, CO2, NOx, and PM emissions. To control CO2 emissions there is no aftertreatment system available. Physical adsorbents such as activated carbon and zeolite are going to be used in this work to reduce emissions from exhaust gases. Zeolite has a greater affinity toward NOx emission, and activated carbon has greater potential to capture HC and carbon dioxide emissions. Initially computational studies were carried out to evaluate back pressure developed in adsorbent chamber. Analysis was carried out by varying conical length of the adsorbent chamber (68 mm, 75 mm

Subramanian, MohanKumar, Muthiya, Solomon Jenoris, Pachamuthu, Senthilkumar, Naveena, B. E., Divya, G. S., Praveen Kumar, M. V.

AFR Adaptation Strategy Based on Lambda Sensor for a Methanol Engine

2025-01-703901/31/2025

Methanol is an main type clean energy and it taken important part for the future internal combustion engine technology. The Equivalent air-fuel ratio (AFR) is very import for the engine combustion of methanol. And a lot of case the ratio between methanol and gasoline is not the constant number. There are no studies about AFR when fuel ratio is arbitrary in the currently. The AFR changes obviously if the tank was fueled with gasoline by mistake at a methanol spark ignition engine. Emission will be affected heavily at this situation because the AFR of gasoline is 2 times more than methanol. Some fuel trim adaptation error will be detected by engine controller or even the engine will stall if engine controller keep use the previous AFR to do the fuel injection control. The Investigation provide a relevant AFR adaption strategy based on lambda sensor and the fuel pipes configuration. The strategy was proved valid by some simulation cases to reduce lambda disturbance, optimize emission

Liu, Yiqiang, Zhong, Jun, Qian, Pengfei, Qiao, Zhiwei, Zhu, Delei, Zhong, Shuanglei, Dong, Yanzhao, Yu, Xiuju

Improving the Carbon Footprint of Long-Haul Trucks Running on First-Generation Biodiesel

2025-01-500701/27/2025

Lowering carbon emissions from road-based transport is required to achieve climate targets. In addition to passenger cars, long-haul trucks contribute more than one-third of on-road generated carbon emissions. Therefore, this sector has great potential to reduce such emissions. Numerous options including electrified drivetrains are possible. Nevertheless, the existing fleet of trucks powered by conventional diesel engines also needs to be addressed. Additionally, a ramp-up of green electricity and charging infrastructure is required to ensure carbon-neutral and reliable transport. Heavy-duty diesel engines are typically suitable for use with first-generation biofuels. However, operational restrictions, such as shorter oil drain intervals are mandatory for users. In the case at hand, the oil change was mandatory after only 30,000 km when pure biodiesel (B100) was used instead of 120,000 km when operating on conventional, mineral oil-based diesel. These boundaries counter efforts to

Rohbogner, Christoph J., Heine, Carsten

Performance Analysis of Graphene-Coated Heat Pipe Heat Exchangers for Automobile Exhaust Cooling and Purification

2025-01-500601/23/2025

This research investigates the development of a heat pipe heat exchanger coated with graphene for cooling and purification of automobile exhausts. The heat exchanger directly affects the performance of the engine because proper heat dissipation and transfer can improve engine performance, reduce fuel consumption, and decrease the emission. Moreover, this effect is much more noticeable on coated heat pipes because of the enhanced thermal conductivity and mechanical properties of the graphene films. A heat null emitted by internal combustion engines was used in the experimental setup to test the thermal performance, cooling efficiency, and purification efficiency of the newly designed in-house exhaust simulation system where the new heat pipes were inserted. The results of the experiment show that the heat pipes have very high thermal performance as the efficiency of the heat pipes was calculated to be around 85%. Furthermore, the temperature decrease over the surfaces of the heat

Karthigairajan, M., Seeniappan, Kaliappan, Balaji, N., Natrayan, L., Sheik, Salman Basha, Ravi, D.

AIRS12242024 (Current)12/24/2024

A-20A Crew Station Lighting

AIR12122024A (Current)12/12/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

AIR12122024 (Historical)12/12/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

ARPTEST3008A (Current)12/12/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

AIR12092024 (Current)12/09/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

Demo Title 12/3/2024

AIR12032024 (Current)12/03/2024

Demo Scope 12/3/2024

A-6 Aerospace Actuation, Control and Fluid Power Systems

Aviation Safety Expert Unites Industry to Safeguard Aviation Supply Chain

TBMG-5212812/01/2024

In the summer of 2023, a receiving clerk in the procurement department of TAP Air Portugal, a Lisbon-based airline, made a curious discovery: A $65 engine part that should have appeared brandnew showed signs of significant wear. The clerk checked the documentation from the London-based parts supplier and noticed that the submitted documentation was also suspicious.

DC-DC Converters for High Reliability eVTOL Auxiliary Power Systems

TBMG-5214712/01/2024

3D-Printed Reactor Core Makes Solar Fuel Production More Efficient

TBMG-5219312/01/2024

In recent years, engineers at ETH Zurich have developed the technology to produce liquid fuels from sunlight and air. In 2019, they demonstrated the entire thermochemical process chain under real conditions for the first time, in the middle of Zurich, on the roof of ETH Machine Laboratory. These synthetic solar fuels are carbon neutral because they release only as much CO2 during their combustion as was drawn from the air for their production. Two ETH spin-offs, Climeworks and Synhelion, are further developing and commercializing the technologies.

Quantitative Analysis of a Hybrid Electric HMMWV for Fuel Economy Improvement

2024-01-3356-TEST-REC11/15/2024

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

Automation 1730608826599

AIR12349999 (Current)11/08/2024

Automation Test Scope

Experimental Study on Quality Control and Variable Valve Timing Strategy of Hydrogen Engine for High Efficiency and Low Emission at Low Load

2024-01-509510/15/2024

In order to reduce the pumping loss of low loads and maximize the lean combustion advantage of hydrogen, the paper proposes a load control strategy based on hydrogen mass, called quality control, for improving thermal efficiency and emissions at low loads. The advantages of quality control and the effect of VVT on the combustion performance of hydrogen internal combustion engines under low loads were discussed. The results show that when the relative air–fuel ratio (λ) increases to more than 2.5, the NOx emissions are reduced to less than 3.5 g/kW · h at the brake mean effective pressure (BMEP) below 8 bar, especially when the BMEP is less than 5 bar, the NOx is within 0.2 g/kW · h. Compared to quantity control based on air mass, the quality control strategy based on hydrogen mass achieves over a 2.0% reduction in pumping loss at BMEP levels lower than 4.4 bar. Furthermore, it enhances thermal efficiency by up to 5% at low loads, while maintaining NOx emissions within 0.2 g/kW · h at

Li, Yong, Chen, Hong, Fu, Zhen, Du, Jiakun, Wu, Weilong

Clutch Torque Optimization for Heavy-Duty Vehicles Starting Based on Intelligent Identification of Driver’s Starting Intention, Vehicle Mass, and Road Grade

02-17-03-001810/08/2024

For heavy-duty vehicles equipped with automated mechanical transmission (AMT), the control of automatic clutch torque is crucial during the start-up process. However, the difficulty of controlling clutch torque is exacerbated by differences in driver’s starting intentions, changes in vehicle mass, and road gradient. Therefore, this article proposes the clutch starting torque optimization strategy based on intelligent recognition of driver’s starting intention, vehicle mass, and road gradient. First, an intelligent recognition strategy is proposed based on the combination of data-driven and onboard transmission control unit (TCU) algorithms, which improves the accuracy of recognizing the driver’s intention to start as well as the vehicle mass and road gradient. Based on the vehicle’s historical state data information, the predictive model is trained offline using a long–short-term memory (LSTM) network to obtain predicted parameter identification results, which are then used to

Geng, Xiaohu, Liu, Weidong, Lei, Yulong, Fu, Yao, Xue, Maohan

Influences of Lubricant Viscosity and Metallic Content on Diesel Soot Oxidation Reactivity

2024-01-508408/23/2024

This study examined the effects of lubricant viscosity and metallic content on the oxidation reactivity of diesel particles. In the first part, the factors affecting thermogravimetric analysis (TGA) experiments was discussed and confirmed. The influences of initial soot mass, heating rate, and airflow rate on soot oxidation rate and experimental reproducibility were investigated to develop an optimized TGA method. On the basis of these experiments, an initial soot mass of 2.0 mg, airflow rate of 4.8 L/h, and heating rate of 2.5°C/h were used for all subsequent TGA tests. It could be found that the TGA experiments had high repeatability, and the differences were less than 0.1%. In the second part, a four-cylinder diesel engine was lubricated with seven kinds of lubricant with different viscosity and metallic content by the use of viscosity index improver (VII), antioxidant and corrosion inhibitor (ACI), and ashless dispersant (AD). Particle samples were subjected to TGA to test their

Meng, Hao, Yang, He, Zhang, Weili, Xing, Jianqiang, Xu, Yan, Wang, Yajun

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