Browse Topic: Single cylinder engines

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Analysis of In-Cylinder Flow for Hybrid Gasoline Engine using High-Speed Particle Image Velocimetry2026-01-0298To be published on 04/07/2026
To curb global warming, reduction of CO2 emissions in automotive powertrains is required. Hybridization and further improvement of thermal efficiency has been promoted in internal combustion engines. Therefore, the 2.0-liter inline 4-cylinder direct-injection engine for 2 motor-hybrid powertrain have been developed to realize rapid combustion by in-cylinder flow enhancement. In this paper, in-cylinder flow analysis using high-speed PIV on the optical single-cylinder engine was performed, and evaluated the combustion promotion concept by analyzing the bulk flow and the turbulence. To achieve rapid combustion, the intake port shape for tumble flow enhancement and bowl-in type piston which was smoothly converted the tumble flow to upward flow were examined. As a method for turbulent component decomposition, the time filter method proposed by the authors were applied. The characteristics of the time filter method is that turbulent component does not include the cycle-by-cycle fluctuations
Okura, Yasuhiro, Urata, Yasuhiro
Advancing Oil Consumption Prediction with 3-D Multiphase CFD: Insights into Piston Design Impacts2026-01-0282To be published on 04/07/2026
Engine oil consumption contributes to hydrocarbon and particulate emissions, catalyst degradation, and reduced thermal efficiency. Reducing it is essential for meeting emission standards and improving engine reliability. This study introduces a 3-D Computational Fluid Dynamics (CFD) framework that captures micron-scale gaps in the piston-ring-cylinder system while accounting for ring dynamics. The model leverages Simerics-MP+ features—including a novel mesh motion strategy and Mismatched Grid Interface (MGI) coupling—to resolve fine crevice regions alongside coarser bulk domains. It incorporates piston translation, ring motion, and crankshaft rotation, and uses the Volume of Fluid (VOF) method to capture multiphase interactions in thin oil films. Compared to experiments, this approach offers detailed flow visualization in optically inaccessible regions at lower cost and complexity. Unlike traditional 1-D models, it captures nonlinear behaviors without relying heavily on parameter
Mohapatra, Chinmoy K., Schlautman, Jeff, Manne, Venkata Harish Babu, schroeder, Debera, Srinivasan, Chiranth
Optimizing an H2 combustion system and investigating abnormal combustions through advanced visualization techniques2026-01-0324To be published on 04/07/2026
The rapidly evolving mobility sector is facing the dual challenge of market expansion and the need for significant emissions reduction. Most of the transition tends to go in favor of electrification, yet it’s widely assumed that no single solution is perfect. Thus, hydrogen as an energy-vector presents a compelling alternative. H2 internal combustion engine use a well-known architecture and utilizes existing production facilities making it a viable short-term and cost-effective option. This context prompted us to investigate the hydrogen spark-ignited internal combustion engine, focusing specifically on critical combustion issues. Various studies have identified recurring challenges such as managing abnormal combustion and achieving high specific power. During our in-house developments, we also faced abnormal combustions and sought to determine the root cause of these issues. Initially, using a modular single-cylinder engine, a combustion system has been optimized regarding injection
LONDOS, Benoit, Bardi, Michele, Serrano, David, Laget, Olivier, Gautrot, Xavier, Bramoullé, Clément, Cordier, Matthieu
Experimental analysis and numerical simulation of the performance parameters of pyrolytic tire oil in a compression ignition engine.2026-01-0345To be published on 04/07/2026
The search for alternative solutions for non-fossil fuels has led to several studies worldwide. This study focuses on environmentally responsible solutions to accelerate tire degradation, focusing on the transformation of these residues into fuel for diesel engines. The objective of this study was to experimentally evaluate, through numerical simulation, the performance of a compression ignition engine operating with Diesel S10, crude and refined pyrolytic tire oil, and mixtures in proportions of 20, 40, and 60% with Diesel oil. The experimental tests were performed on a single-cylinder engine coupled to a dynamometer bench, and the numerical simulation was performed using the Diesel Engine RK software. The experimental results indicated that increasing the proportion of refined pyrolytic oil in diesel slightly improves engine performance up to approximately 2750 RPM, after which the performance is reduced compared to pure Diesel. The addition of crude pyrolytic oil slightly improves
Santana, Claudio Marcio, Prudente, Lucas Rhuan, ROCHA, ANA MAURA, Peixoto, Claudio
Potential of a Hydrogen Fuel-Share Combustion Concept for a Conventional Medium-Speed Marine Diesel Engine2026-01-50072/2/2026
To meet the International Maritime Organization’s (IMO) short-term greenhouse gas (GHG) reduction targets, partial decarbonization of the existing fleet, often powered by medium-speed diesel engines, is required. One approach for reducing CO2 emissions is to enrich the charge air with hydrogen to substitute diesel. However, hydrogen’s high reactivity can lead to combustion abnormalities such as backfire, pre-ignition, and knocking, thus limiting the feasible admixture rates. These challenges are particularly relevant in medium-speed diesel engines designed for high power output and efficiency at low rpm. While hydrogen fuel-share has previously been tested in small-bore engines at moderate loads, this study investigates the influence on combustion and achievable hydrogen admixture rates in a medium-speed, 4-stroke diesel engine operating with up to 30 bar net indicated mean effective pressure (net IMEP). To minimize retrofitting efforts and to preserve diesel performance, the
Achenbach, Tobias, Meinert, Robert, Mahler, Kay, Kunkel, Christian, Rösler, Sebastian, Prager, Maximilian, Jaensch, Malte
Comprehensive Evaluation and Development of a Single Cylinder Engine Vehicle for Refinement of NVH Characteristics2026-26-03081/16/2026
The scale of worldwide population presents its own set of difficulties, especially in densely populated cities. Almost every individual has some form of personal transport, which leads to congestion and limited parking space. Automotive manufacturers are scaling down the size of vehicles to resolve these issues to some extent. This paper is based on the NVH development of a single cylinder diesel engine vehicle. It provides an insight into the comprehensive vehicle level NVH refinement approaches adopted. The NVH characteristics of benchmark two-cylinder diesel and baseline vehicle were measured and analyzed for target setting. The performance of each subsystem such as engine mounting, vehicle structure, intake and exhaust was evaluated, and gap analysis was performed against set targets. It was found that the engine mounting system and vehicle structure were inefficient in isolating the excitation forces. The design and location of the mounting system was evaluated using CAE and
Ghale, Guruprasad Chandrashekhar, Baviskar, Shreyas, Bendre, Parag, Kamble, Pranit, Bhangare, Amit, THAKUR, SUNIL, Kunde, Sagar, Wagh, Sachin
Optimization of Biogas Combustion in SI Engines Applied to the Pre-Chamber Ignition System2025-36-020912/18/2025
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Siqueira, Caio Henrique Moreira, Ázara, Luiz Eduardo Martins, Ribeiro, José Vitor Puttini, Soares, Gabriel Faria, Silva, Fábio Moreira, Alvarez, Carlos Eduardo Castilla
Development of a Comprehensive Predictive QD Knock Simulation Model for Hydrogen, Methanol, and an Ammonia–Hydrogen Blend2025-01-052811/25/2025
To support the transition toward climate-neutral mobility and power generation, internal combustion engines (ICEs) must operate efficiently on renewable, carbon-neutral fuels. Hydrogen, methanol, and ammonia-hydrogen blends are promising candidates due to their favorable production pathways and combustion properties. However, their knock behavior differs significantly from conventional fuels, requiring dedicated simulation tools. This work presents a modeling framework based on quasi-dimensional (QD) engine simulation, including two separate knock prediction models. The first model predicts the knock boundary of a given operating point and combines an auto-ignition model with a knock criterion. The overall methodology was originally developed for gasoline and is here adapted to hydrogen, methanol, and ammonia-hydrogen blends. For this purpose, the relevant fuel properties were incorporated into the auto-ignition model, and a suitable knock criterion was identified that applies to all
Benzinger, Steffen, Yang, Qirui, Grill, Michael, Kulzer, Andre Casal, Plum, Lukas, Hermsen, Philipp, Günther, Marco, Pischinger, Stefan, Hurault, Florian, Foucher, Fabrice, Rousselle, Christine
Sustainable Engines with Carbon-Neutral Fuels – Fast Adaptation for Efficient Multi-Fuel Operation by Tailored Charge Motion Design2025-01-053411/25/2025
As a fundamental element of measures to reduce the carbon footprint of commercial applications, carbon-neutral fuels are increasingly coming into focus for heavy installations. In addition to diesel substitute fuels, alternative energy carriers like NG, H2, MeOH and NH3 are gaining increasing attention. The energy conversion of these fuels is typically taking place on the principle of premixed combustion, which places different demands on fuel injection and mixture formation, as compared to optimized diesel-like combustion. Accordingly, the demand to layout multi-fuel capable engine designs centers to a high share on the above-mentioned design that can burn these different fuels with high efficiency and support a high degree of commonality with the in-series engine to carry over reliable operation and to maintain attractive cost figures. FEV has developed the Charge Motion Design (CMD) process, which can be applied to design the intake ports and combustion chambers for multi-fuel
Koerfer, Thomas, Dhongde, Avnish, Boberic, Aleksandar, Zimmer, Pascal, Pischinger, Stefan
Measurement of the Liquid Fuel Film on the Combustion Chamber Wall of a Gasoline Engine using a Novel Capacitive Sensor2025-32-001811/3/2025
The reduction of exhaust emissions and particulate matter from internal combustion engines remains a critical challenge, particularly under cold start and warm-up conditions, where a significant portion of total emissions is generated. In spark-ignition (SI) gasoline engines, the formation of liquid fuel films on intake ports wall, piston and cylinder wall surface significantly contributes to unburned hydrocarbon and particulate emissions. Also, the fuel film adhering to the wall can be a cause of the lubricating oil dilution. To address these issues, a novel capacitive sensor, fabricated using MEMS technology, was developed and applied to investigate the behavior of liquid fuel films formed inside the combustion chamber of a single-cylinder engine. The sensor detects changes in capacitance caused by fuel film adhesion to the sensor surface. The sensor was installed in a single-cylinder test engine along with a direct fuel injector allowing for the controlled formation of fuel films on
Kuboyama, Tatsuya, Nakajima, Takeru, Moriyoshi, Yasuo, Takayama, Satoshi, Nakabeppu, Osamu
Advanced 3D Simulations of a Four-Stroke High-Performance Engine Valvetrain for the Analysis of the Mechanical Stresses and Energy Losses2025-32-001011/3/2025
Enhancing the performance of naturally aspirated 4-stroke engines relies heavily on improving trapping efficiency, increasing maximum engine speed, and reducing friction losses. In this regard, the valvetrain plays a critical role. Achieving high volumetric efficiency at higher engine speeds necessitates very steep valve opening and closing ramps, making this aspect pivotal in the design process. At high engine speeds, significant dynamic phenomena arise, including valve float during the lift phase and valve bounce during the closing phase. These effects not only induce substantial modifications to the valve lift curve but also increase the mechanical stress on critical components such as the valve and the rocker arm, thereby elevating the risk of failure. Moreover, the timing system substantially contributes to overall engine losses due to frictional energy dissipation, which results from the numerous interactions between moving components. The present work aims to develop a numerical
Tarchiani, Marco, Pizzicori, Alessio, Raspanti, Sandro, Romani, Luca, Meli, Enrico, Ferrara, Giovanni, Trassi, Paolo
Effect of In-Cylinder Hydrogen Mixture Formation on Hydrogen Combustion2025-32-006511/3/2025
Global efforts to mitigate climate change include ambitious long-term strategies by countries to achieve net-zero greenhouse gas emissions by 2050. The automotive sector is exploring carbon-free powertrains, with hydrogen emerging as a key technology. Its zero-emission potential positions it for widespread adoption in power generation, transportation, and industry. Hydrogen engines, particularly direct injection engines offering high power and efficiency, are gaining traction due to their adaptability using existing engine components. However, in a hydrogen direct injection engine, achieving proper mixing of hydrogen and air in the cylinder is challenging, making in-cylinder mixture formation a crucial factor for ensuring stable combustion. To predict hydrogen mixture formation in the cylinder, we conducted a Schlieren visualization experiment of the hydrogen jet. Based on the results, a detailed hydrogen jet model for the direct injection injector was developed. This model was then
Hisano, Atsushi, Saitou, Masahito, Sakurai, Yota, Ichi, Satoaki
Design, Optimization and Calibration of a Single-Cylinder, Motorcycle Engine for Integration into a Novel Formula SAE Electric Hybrid Powertrain2025-32-004511/3/2025
The Formula SAE competitions often drive changes in the automotive research field by developing, implementing and emphasizing new technologies for both on-road and on-track applications and by training future engineers, mechanics, logistics and administrative personnel. In this work, the adaptation of a motorcycle, single-cylinder engine for the installation in an electric hybrid car for Formula SAE races is described, focusing on the design of intake and exhaust parts and on the development of the fully open-access Engine Control Unit (ECU) code. In the first part of the work, the 1-D model of the engine is developed and used to design the intake and the exhaust parts needed to make the Formula Student car rules compliant. In particular, the intake manifold and the intake ducts have been designed with the assistance of the engine model to optimize the engine response under transient conditions and to maximize the power. On the other hand, the exhaust line was designed to increase the
Brusa, Alessandro, Fabbri, Pietro, Shethia, Fenil, Bassani, Davide, Petrone, Boris, Cavina, Nicolo
A Study of Knocking Characteristics in a Hydrogen SI Engine under High Compression Ratio2025-32-006311/3/2025
This study investigated the knocking characteristics of a hydrogen spark ignition engine for the purpose of increasing efficiency and expanding the operating range. In recent years, research focused on carbon neutrality has been vigorously conducted, and hydrogen has attracted attention as a next-generation fuel for internal combustion engines (ICEs). The combustion characteristics of hydrogen are vastly from those of existing gasoline. It is essential to have a sufficient understanding of the combustion characteristics of hydrogen in order to develop next-generation ICEs designed to operate on hydrogen fuel. There are especially many aspects of the knocking mechanisms of hydrogen that are unclear. Consequently, those characteristics and mechanisms must be clarified for the purpose of expanding the operating range of hydrogen engines and enhancing their efficiency. In this study, experiments were conducted using a single-cylinder hydrogen engine that was operated at a high compression
Ishihara, Hiromasa, Kishibata, Shunsuke, Miyake, Shota, Iida, Tomoya, Kuwabara, Kenta, Yoshihara, Shintaro, Miyamoto, Sekai, Iijima, Akira
Firing TDC Identification Through Wasted Spark Duration Measurements During Cranking of Small Engines2025-32-008511/3/2025
Implementing control techniques through “virtual sensors” is extremely attractive for small size engines, given that cost effectiveness is essential. This work presents a routine for identifying the firing TDC through measurement of spark duration. Previous capability of correctly identifying cycle phasing through this route was confirmed during normal operation of a power unit that featured a wasted spark ignition system. Starting with the hypothesis that this could be implemented during engine cranking, the procedure was adapted for identifying the firing TDC as quickly as possible; it was also developed with the specific task of requiring less time for synchronization, compared to the previous version. The new method was verified on a small size 50 cc single cylinder engine that featured a recoil starter mechanism. Correct identification was confirmed, with the possibility of generating the reference signal as early as the 2nd cycle that featured normal operation of the ignition
Irimescu, Adrian, Merola, Simona
Approaches for Mechanical Development and Validation of Hydrogen Internal Combustion Engines2025-01-039810/7/2025
Hydrogen Internal Combustion Engines (H2 ICEs) are seen as a viable zero-emission technology that can be implemented relatively quickly and cost-effectively by automotive manufacturers. The changed boundary conditions of a hydrogen-fueled engine in terms of mechanical and thermal aspects require a review and potential refinement of the design especially for the 'piston bore interface' (liner honing, ring and piston design) but also for other engine sub-systems, e.g. the crankcase ventilation system. The influence of oil entry into the combustion chamber is even more important in hydrogen engines due to the risk of oil-induced pre-ignition. Therefore, investigations of the interaction between friction, blowby and oil transfer into the combustion chamber were performed and are presented in this paper. During the investigations, experimental tests were carried out on a single-cylinder engine ('floating liner') and on a multi-cylinder engine. The 'floating liner' concept allows the crank
Plettenberg, Mirko, Gell, Johannes, Grabner, Peter, Gschiel, Kevin, Hick, Hannes
ML-based Identification of Lactones for Blend Studies and Combustion Performance in a Spark-Ignition CFR Engine2025-24-00719/7/2025
The identification of sustainable fuels that exhibit optimal physico-chemical properties, can be synthesized from widely available feed-stocks, enable cost-effective large-scale production, and integrate seamlessly with existing infrastructure is essential for reducing global carbon emissions. Given their high energy density, efficient handling, and versatility across applications, renewable liquid fuels remain a critical component of even the most ambitious energy transition scenarios. Lactones, cyclic esters derived from the esterification of hydroxycarboxylic acids, feature a ring structure incorporating both a carbonyl group (C=O) and an ether oxygen (O). Variations in ring size and carbon chain length significantly influence their physicochemical properties, which in turn affect their performance in internal combustion engines. According to predictive models based on artificial neural networks, valerolactone, hexalactone, and heptalactone isomers show promise as fuels in spark
Sirna, Amanda, Loprete, Jason, Ristow Hadlich, Rodrigo, Assanis, Dimitris, Patel, Rutvi, Mack, J. Hunter
Methodology for the Study of Hydrogen Combustion in an Optical Spark Ignition Engine2025-24-00629/7/2025
The use of hydrogen as a fuel in internal combustion engines represents a promising alternative for reducing CO2 emissions. To optimize its efficiency and better understand the phenomena associated with its combustion, it is essential to have advanced visualization techniques for a better understanding of the processes involved. This paper presents the methodology used in the development of an optical engine for the study of hydrogen combustion, designed from a 454cc single-cylinder engine. The configuration of the optical system is described, which includes the use of high-speed cameras to capture the spark plug activation as well as the flame propagation in the combustion chamber. The engine has two optical accesses, one through the piston and one at the top of the cylinder that allows side viewing of the combustion chamber. In addition, the experimental procedure that alternates combustion cycles with motoring cycles, the determination of the air-hydrogen ratio with which the engine
Pastor, Jose V., Novella, Ricardo, Tejada, Francisco J., Cáceres-Carías, José
Water Injection Effects on a Heavy-Duty Hydrogen Spark Ignition Engine2025-24-00509/7/2025
Hydrogen engines have gained interest recently, as they present a promising alternative for decarbonizing heavy-duty transport, aligning with carbon neutrality regulations. This study investigates the effects of inlet manifold water injection on a heavy-duty hydrogen-fueled spark ignition single-cylinder engine, focusing on moderating abnormal hydrogen combustion and its impact on performance, thermal efficiency, and exhaust emissions. Water injection has been identified as a potential solution to mitigate the challenges associated with hydrogen combustion, such as pre-ignition and knock, by reducing the reactivity of the mixture (lowering temperature and increasing the dilution). The lower reactivity of the mixture allows running richer lambdas or higher compression ratios without spontaneous preignition, mitigating boosting requirements for full load and transient performance. Experimental results demonstrate that water injection significantly improves engine performance, thermal
Peñin Garcia, Alfonso Jose, Valls Claramunt, Carles, Rivas, Manuel, Birnstingl, Johannes, Wieser, Martin, Martin, Jaime, Novella, Ricardo
Ammonia Combustion with Ignition Improvement Measures in a High-Speed Marine Application2025-24-00259/7/2025
Ammonia (NH3) has gained significant attention as a zero-carbon fuel which is capable of supporting global decarbonization goals, especially in the maritime transportation and power generation sectors. Its hydrogen density, storage feasibility, established production methods, and transportation infrastructure are key benefits which contribute to its potential both as a hydrogen carrier and as a direct fuel. The study investigates the combustion characteristics and emission profiles of ammonia on a spark ignited 2.13L single cylinder engine with the goal of evaluating ammonia as a single fuel. This displacement is representative of the typical cylinder displacement of small to mid-size engines for marine applications on sportfishing boats and as auxiliary power units. Challenges to consider for ammonia combustion are its high ignition energy requirement and low laminar flame velocity. Several methods were employed to compensate for these properties such as increasing compression ratio
Li, Zhengling, Lückerath, Moritz, Pischinger, Stefan, Boberic, Aleksandar, Franzke, Bjoern, Dhongde, Avnish, Jagodzinski, Bartosch, Burrows, John, Korkmaz, Metin
Toward Sustainable Heavy-Duty Transport: Evaluating Charge Dilution and Advanced Corona Ignition System Effects on SI Natural Gas Engine Efficiency and Combustion Characteristics2025-24-00249/7/2025
Reducing greenhouse gas (GHG) emissions in the transportation sector is a significant challenge. A multi-technology approach is the most practical and sustainable solution for minimizing the environmental impact of road transport. Alternative gaseous fuels derivable from bio sources have the potential to significantly cut equivalent carbon dioxide (CO2eq) emissions from a Well-to-Wheel (WtW) perspective, and the development of technologies that allow to improve the efficiency of natural gas-powered Heavy Duty (HD) Spark Ignition (SI) engines is of strategic importance. In such applications, charge dilution strategies might have the potential to increase engine efficiency at a relatively low implementation cost. Diluting the in-cylinder charge can reduce fuel consumption by decreasing wall and pumping losses, and increasing the Heat Capacity Ratio (γ). The coupling with innovative technologies aimed at enhancing ignition energy, influencing combustion development, could be a promising
Di Domenico, Davide, Napolitano, Pierpaolo, Papi, Stefano, Ricci, Federico, Golini, Stefano, Rapetto, Nicola, Giordana, Sergio, Beatrice, Carlo
Numerical and Experimental Investigation of a Pre-Chamber Igniter for Enhanced Low Load Stability in Internal Combustion Engines2025-24-00029/7/2025
Developing innovative ignition technologies offers a crucial opportunity to improve the performance of internal combustion engines while significantly reducing harmful emissions, contributing to a more sustainable future. The replacement of the standard spark plug with a pre-chamber igniter is a well-known combustion accelerator for externally ignited engines for passenger vehicles. An increase in engine efficiency, especially at high loads, can be realized. However, pre-chamber ignition technology has not yet been widely adopted in the market, primarily due to the difficulty of achieving stable operation at lower engine loads. A better understanding of the flow and mixture conditions is needed to improve the combustion stability with the pre-chamber igniter in low-load operating conditions. The gas exchange in the passive pre-chamber was studied using a combination of numerical modelling and experimental methods. Accessing those parameters experimentally requires a high effort in test
Fellner, Felix, Härtl, Martin, Jaensch, Malte, D'Elia, Matteo, Burgo Beiro, Marcos, Nambully, Suresh Kumar, Rothbauer, Rainer
Combustion System Optimization of Commercial Vehicle Hydrogen Engines via 3DCFD Simulations and Single Cylinder Engine Measurements: Injector Cap, Injection Strategy and Intake Duct Design2025-24-00089/7/2025
The development of hydrogen fueled engines has dramatically accelerated in recent years. They have gained much in operating reliability and the specific power outputs is at least comparable to those of current natural gas engines. This has been made possible by combining specific development tools derived from the development of compression-ignition and spark-ignition engines. These include jet visualization techniques (Schlieren, PIV, and LIF), video endoscopy on engine, and 3-D fluid dynamics simulations. In hydrogen engines for commercial vehicles, efforts have so far been made to keep engine components as unchanged as possible from similar diesel or gasoline versions. Similarly, some manufacturers have favored the port fueled injection (PFI) solution because it is easier to implement than the in-cylinder (DI) injection one. The present work concerns the evaluation of the further improvement potential made possible by using direct injection (DI) technology, and intervening on both
Gaballo, Maria Rosaria, Iacobazzi, Marino, Burtsche, Thomas, Cornetti, Giovanni
A Novel Chemical Kinetics-Based Approach for Studying Feasibility and Optimise Retrofitting Strategies of Hydrogen CI Engines: Application to a Laboratory-Scale Single-Cylinder Engine2025-24-00549/7/2025
The climate emergency has prompted countries to adopt strategies to limit the rise in global temperatures by promoting low-carbon technologies. In this context, hydrogen (H2) can be considered a viable solution, especially in road and marine transportation, where Compression Ignition (CI) internal combustion engines (ICEs) are widely used. Despite its potential to significantly reduce pollutant emissions compared to fossil fuels, hydrogen presents a major challenge for CI engines due to its high autoignition temperature (greater than diesel). To overcome this problem, a novel methodology is proposed to evaluate the feasibility of hydrogen retrofitting. Each engine operating point is simulated as an ideal zero-dimensional (0D) reactor into which a diesel-hydrogen-air mixture is introduced. A fully detailed kinetic mechanism is used to simulate the complex chemical interactions between the two fuels, as well as its significant effect on engine behaviour, obtaining accurate predictions of
Episcopo, Domenico, Rossetti, Salvatore, Mancaruso, Ezio, Saponaro, Gianmarco, Camporeale, Sergio, Laera, Davide
Modeling and Experimental Study on Spark-Ignition Engine Using Hydrogen–Methane–Blended Fuel2025-01-50568/22/2025
A combustion model of a hydrogen–methane–blended fuel for internal combustion engines is developed and validated. Mixed fuels include hydrogen–methane, octane–methanol, and octane–ethanol blends. To address the complex dependencies of laminar flame speed of hydrogen–methane–blended fuel on temperature, pressure, equivalence ratio, and exhaust gas recirculation (EGR) ratio, a machine learning–based model was constructed. Gaussian process interpolation and polynomial extrapolation were employed to create a comprehensive laminar flame speed map. Additionally, two flame-quenching models, wall quenching and turbulent flame stretching, were introduced to predict unburned hydrocarbons. NOx emissions were estimated using the extended Zel’dovich mechanism. The accuracy of these models was verified by comparing numerical simulations with experimental data from single-cylinder engine experiments. Results showed strong agreement for cylinder pressure, heat release rates, and emissions across
Hayashi, Shinji, Yamada, Toshiyuki, Omori, Yuya, Nakagawa, Kentaro, Tanaka, Kotaro
Ethanol Fuel as Enabler for High-Efficiency and Low-Soot Combustion in Dual-Fuel and Blend Modes03-18-04-00287/16/2025
Global climate initiatives and government regulations are driving the demand for zero-carbon tailpipe emission vehicles. To ensure a sustainable transition, rapid action strategies are essential. In this context, renewable fuels can reduce lifecycle CO2 emissions and enable low-soot and NOx emissions. This study examines the effects of renewable ethanol in dual-fuel (DF) and blend fueling modes in a compression ignition (CI) engine. The novelty of this research lies in comparing different combustion modes using the same engine test rig. The methodology was designed to evaluate the characteristics of various injection modes and identify the inherent features that define their application ranges. The investigation was conducted on a single-cylinder engine equipped with state-of-the-art combustion technology. The results indicate that the maximum allowable ethanol concentration is 30% in blend mode, due to blend stability and regulatory standards, and 70% in DF mode, due to combustion
Belgiorno, Giacomo, Ianniello, Roberto, Di Blasio, Gabriele
Variable Valve Actuation and Multiple Injections to Enhance the Gas Exchange of a Passive Pre-Chamber Igniter2025-01-03157/2/2025
Pre-chambers, in general, represent an established technology for combustion acceleration by increasing the available ignition energy. Realizing rapid fuel conversion facilitates mixture dilution extension with satisfying combustion stability. More importantly, knock-induced spark retarding can be circumvented, thus reducing emissions and increasing efficiency at high engine loads. Adapted valve actuation and split injections were investigated for this study to enhance the gas exchange of a passive pre-chamber igniter in a single-cylinder engine. The findings support the development of passive pre-chamber ignition systems operable over the whole engine map for passenger vehicles. There are two configurations of pre-chamber igniters: passive pre-chambers and scavenged pre-chambers. This study focuses on the passive design, incorporating an additional small volume around the spark plug into the cylinder head. Hot jets exit this volume after the ignition onset through several orifices
Fellner, Felix, Härtl, Martin, Jaensch, Malte
Effect of Gasoline Component on Fuel Economy of WLTC Drive with EGR and Lean Combustion2025-01-03057/2/2025
It is becoming increasingly clear that research into alternative fuels, including drop-in fuels, is essential for the continued survival of the internal combustion engine. In this study, the authors have evaluated olefinic and oxygenated fuels as drop-in fuels using a single-cylinder engine and considering fuel characteristic parameters. The authors have assessed thermal efficiency by adding EGR or excess air from zero to the maximum value that allows stable combustion. Next, we attempted to predict fuel efficiency for four types of passenger cars (Japanese small K-car N/A, K-car T/C, Series HV, and Power-split HV) by changing the fuels. We created a model to estimate fuel efficiency during WLTC driving. The results indicated that fuel economy could potentially be improved by adding an olefin fuel that burns stably even with a large amount of EGR or air and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was particularly notable for
Moriyoshi, Yasuo, Xu, Fuguo, Wang, Zhiyuan, Tanaka, Kotaro, Kuboyama, Tatsuya
Analysis of Combustion Characteristics of a Small 2-Stroke Opposed Piston Engine Using an Optically Accessible Engine and Numerical Analysis2025-01-02236/16/2025
As global warming becomes more serious, decarbonization of internal combustion engines, which emit a large amount of carbon dioxide, is being promoted. It is predicted that many vehicles will still be equipped with engines in 2035, and a variety of powertrains will be required in the future. Therefore, we focused on the opposed-piston engine as an internal combustion engine specialized for power generation applications. The opposed-piston engine is characterized by its light weight due to the absence of a cylinder head, low S/V ratio due to the ultra-long stroke, reduced cooling loss due to the long stroke, and reduced vibration due to the offsetting of the reciprocating inertial forces of the left and right pistons. We believe that the engine for power generation can achieve the required high efficiency operation and vibration reduction. Therefore, in this study, combustion analysis of a two-stroke opposed-piston engine with features of low vibration, high efficiency, and high output
Yamazaki, Yoshiaki, Watanabe, Sou, Okawara, Ikumi, Otaki, Yusuke, Liu, Jinru, Iijima, Akira
Combustion and Emission Characteristics of Marine Ammonia-Diesel Dual Fuel Engine with Micro-Pilot Injector Change2025-01-02356/16/2025
Recently, as regulations on greenhouse gas emissions have become stricter, driven by global warming, there is increasing interest in engines utilizing environmentally friendly fuels. In this context, ammonia is attracting attention as a potential alternative to fossil fuels in the future. However, due to its distinct fuel properties compared to conventional fuels, research is being conducted on utilizing diesel as an ignition source for ammonia. In this study, the effects of diesel injector fuel flow rate, and micro-pilot (MP) diesel injection timing on combustion and exhaust emission characteristics were analyzed in a single cylinder 12L marine ammonia-diesel dual-fuel engine. Two types of diesel micro-pilot injectors were tested. The first one was high flow rate micro-pilot injector (HMPI) and the second one was low flow rate micro-pilot injector (LMPI). HMPI injector had 66% more number of fuel injector nozzle hole and 250% larger fuel flow rate. Therefore, HMPI injector could
Jang, Ilpum, Park, Cheolwoong, Kim, Minki, Park, Chansoo, Kim, Yongrae, Park, Gyeongtae, Lee, Jeongwoo
Thermal Efficiency Improvement and Emission Reduction of Methanol Spark Ignition Engine Using Lean-Burn Strategy2025-01-02246/16/2025
Methanol is a promising fuel for achieving carbon neutrality in the transportation sector, particularly for internal combustion engine vehicles. With its high-Octane number, methanol enables higher thermal efficiency compared to gasoline engines. Additionally, its wide flammability range allows stable engine operation under lean burn conditions at low to mid-load levels. These characteristics make methanol well-suited for lean-burn strategies, which reduce pumping losses and enhance thermal efficiency. However, there remains a lack of studies on the influence of injection timing under different lean conditions, particularly in a wall-guided spark ignition engine. Wall-guided systems use the chamber wall or piston surface to redirect and stratify the fuel-air mixture near the spark plug at the time of ignition. The combustion performance of lean-burn engines in highly sensitive to variations in injection and excess air ratio. In this study, experiments were conducted on a single
Lee, Seungwon, Kim, Hyunsoo, Hwang, Joonsik, Bae, Choongsik
Improvement of Lean Burn Characteristics with Ozone Addition in a Diesel Micro-pilot Natural Gas Engine2024-32-01044/18/2025
Ozone (O3) was introduced into the intake air in a natural gas fueled engine ignited by micro-pilot of diesel fuel, to utilize the reactive O-radicals decomposed from the O3 for the promotion of the combustion and for improvements in the thermal efficiency and exhaust emissions. Experiments were carried out in a single cylinder engine to elucidate the effects of the ozone addition under the lean burn conditions. A supercharger was employed to increase the intake air amount and vary the equivalence ratio of natural gas. The experimental results showed that the O3 addition has a limited effect on the ignition of the diesel fuel injected near top dead center, while the heat release during the flame propagation in the natural gas/air mixture was increased at the lower equivalence ratio of natural gas. Further the ignition of natural gas was promoted, resulting in the increase of the combustion efficiency and the degree of constant volume heat release. The cooling loss and the NOx emissions
Kobashi, Yoshimitsu, Miyata, Shoki, Kawahara, Nobuyuki, Inagaki, Ryuya
Dynamic Analysis of Intake and Exhaust Valve Motion in a High-Performance four Stroke Engine. Part 2 - Development of a Numerical Model for the Simulation of the Valvetrain2024-32-00844/18/2025
The intake and exhaust valve motion have, as known, a pivotal role in determining engine operation and performances. When dealing with high specific power engines, especially at high rpm, the dynamic behavior of the valve can differ from the kinematic one defined during the design phase. This is related to the high acceleration and forces to which the valve and the other components of the valvetrain system are subjected. In particular, the valve can detach from the cam profile at the end of the opening stroke, and it can show a bouncing behavior during the closing stroke. In addition, all the elements of the valvetrain system are not infinitely rigid and aspects such as the timing chain elongation, the camshaft torsion and the valve stem compression can determine a change in phase with respect to the kinematic one. Since the high complexity level of valvetrains, advanced numerical simulations are mandatory to deeply analyze the behavior of the whole mechanism and each subsystem. The
Tarchiani, Marco, Romani, Luca, Raspanti, Sandro, Bosi, Lorenzo, Ferrara, Giovanni, Trassi, Paolo, Fiaschi, Jacopo
Techniques and Analysis Methods Used in Development of 13.4kW Horizontal Water-Cooled Diesel Engine2024-32-01164/18/2025
Horizontal water-cooled diesel engines are single-cylinder engines equipped with all the necessary components for operation such as a fuel tank and a radiator. Due to their versatility, there are used in a wide range of applications in Asia, Africa, South America, etc. It is necessary to comply with strengthened emissions regulations year by year in countries where environmental awareness is increasing such as China, India, etc. We have developed a new compact and high-power 13.4kW(18HP) engine which meets these needs. We realized a high-power density by using our unique expertise to maintain an engine size and increase a displacement. In addition, by optimizing a layout of crankcase ribs through structural analysis, we have achieved a maximum bore and “Reduction of the weight of the crankcase and lubricating oil consumption (LOC), and reduction of friction with narrow-width low-tangential load piston rings”. Furthermore, by designing an intake port using 3D CFD, we have optimized a
Shiomi, Kenta, Hosoya, Ryosuke, Komai, Yoshinobu, Takashima, Yusuke, Kitamura, Takahiro, Fujiwara, Tsukasa, Suematsu, Kosuke
Impact of Oxygenated Fuel Components on Engine Performance and Particulate Emissions in Gasoline Blends2025-01-84464/1/2025
The challenges with electrification in the automotive industry have led to rethinking the decisions to ban internal combustion engines. Nonetheless, decarbonization of transportation remains a regulatory priority in many countries, irrespective of the energy source for automotive powertrains. Renewable oxygenated fuel components can help with the rapid decarbonization of gasoline fuels in the current fleet. Ethanol is one of the primary renewable components typically used for blending in gasoline primarily at 10% v/v but up to 20% v/v substitution which corresponds to 3.7 to 8.0% oxygen by mass. However, a range of oxygenates could be used instead of ethanol. This study aimed to determine if the engine could discriminate between different oxygenates in gasoline fuels blended at the same octane (RON) and oxygen levels. Oxygenates such as methyl-tert-butyl-ether (MTBE) and ethyl-tert-butyl-ether (ETBE) were considered in this study. Blends were made using a combination of n-heptane, iso
Kalaskar, Vickey, Mitchell, Robert, Pourreau, Daniel
10 % Fuel Economy Benefit at Part Load and up to 33 % at Idle for a Diesel Engine via Reducing Friction. Testing the Rotating Liner Engine and an Identical Baseline Under Load2025-01-83904/1/2025
The Rotating Liner Engine (RLE) is a design concept where the cylinder liner of a heavy-duty Diesel engine rotates at about 2-4 m/s surface speed to eliminate the piston ring and skirt boundary friction near the top and bottom dead center. Two single cylinder engines are prepared using the Cummins 4BT 3.9 platform, one is RLE, the other is baseline (BSL), i.e. conventional. In 2022, we published the test results of the RLE under load, but we lacked detail test data for the baseline. In this new set of experiments, we compare the RLE performance at idle and under load of up to about 7 bar IMEP (indicated mean effective pressure) to the baseline under similar conditions. It has been proven that the elimination of metallic contact between the compression rings and cylinder wall takes place with a liner speed of 1.5-2.3 m/s surface speed (283-426 rpm for the 102 mm bore) for the 850-1280 rpm crankshaft speed. The RLE FMEP is substantially reduced under load, which is a trend opposite to
Dardalis, Dimitrios, Hall, Matthew, Riley, Sebastian, Basu, Amiyo, Matthews, Ron
Enhancing Dual Fuel Combustion Simulation: A Novel Geometric Approach for Accurate Flame Entrainment Estimation2025-01-83664/1/2025
Maritime transportation plays a vital role in the economy and is one of the most energy-efficient modes of transportation. However, it is a growing source of greenhouse gas emissions. A potential solution to lower carbon emissions from maritime transport is to use renewable fuels in marine engines. Hydrogen or methanol can serve as the primary energy source in internal combustion (IC) engines. However, their high autoignition temperatures require an external ignition source to start combustion in compression ignition (CI) engines. The Dual Fuel (DF) approach offers an effective method for incorporating these fuels. To accurately simulate dual fuel combustion, certain parameters need to be carefully addressed. One crucial parameter to investigate is estimating the flame entrainment area, as it directly affects the mass burning rate. In this work, a novel geometric approach is developed to estimate the evolution of the flame entrainment area. This model is integrated into a multi-zone
Parsa, Somayeh, Daenens, Arthur, Verschaeren, Roel, Dierickx, Jeroen, Verhelst, Sebastian
Experimental Study of Glow Plug Assisted Methanol Compression Ignition2025-01-84124/1/2025
Methanol can be produced renewably and used in compression ignition (CI) engines as a replacement for fossil diesel. However, methanol is a low cetane fuel, creating challenges in achieving stable operation, particularly at low load. One potential solution is through surface ignition via a glow plug. In this work, experiments were conducted on a methanol-fueled 2.1 L single cylinder engine instrumented with a glow plug. The engine was designed for alcohol combustion with an elevated compression ratio (26:1) and a narrow injector umbrella angle (120 degrees) compared to standard diesel compression ignition hardware. As such, no plume was directly intercepted by the glow plug. A representative low load case of two conventional mixing controlled compression ignition (MCCI) strategies (single injection and pilot-main) and three kinetically controlled advanced CI strategies (homogenous charge compression ignition, split injection, partially premixed combustion) were tested with and without
Gainey, Brian, Svensson, Magnus, Verhelst, Sebastian, Tuner, Martin
Experimental and Numerical Investigation of Different Dilution Techniques in a High-Performance H2 - Fueled SI Engine2025-01-84244/1/2025
Nowadays, hydrogen (H2) is rising as a key solution to fuel internal combustion engines (ICE) since it allows carbon free combustion process. At the same time, ICE fueled with H2 can reach similar performance and driving experience of gasoline fueled ones. In stoichiometric conditions, hydrogen shows higher flame speed, lower ignition energy and lower quenching distance than gasoline. Mainly for these reasons, H2 combustion is characterized by a high risk of abnormal combustion (i.e. knock and pre-ignition), relevant NOx emissions and high heat losses. On the other hand, the wide flammability range and high combustion stability of H2 allow the use of different techniques to reduce combustion reactivity. This work presents a combined approach, experimental and numerical, to assess the benefits of three mixture dilution methods. The experimental campaign, in different operating conditions, was carried out on a production derived high specific power gasoline Single Cylinder Engine (SCE
Tonelli, Roberto, Medda, Massimo, Gullino, Fabrizio, Silvestri, Nicola, Zaffino, Francesco, Mariconti, Roberto, Rossi, Vincenzo
Nitrogen Oxides Reduction Potential Via Water Direct Injection in a Single-Cylinder Hydrogen-Fueled Direct Injection Spark Ignition Engine2025-01-84274/1/2025
In hydrogen-fueled internal combustion engine (H2ICE), there are some ways to reduce nitrogen oxides (NOx) emissions. Using the wide flammability range of hydrogen, such as conducting lean combustion to reduce nitrogen oxides and employing exhaust gas recirculation (EGR), have been adopted. However, challenges exist in terms of load expansion, and due to the absence of high heat capacity of carbon dioxides in the exhaust, EGR also struggles to exhibit significant effects. In such a scenario, there is growing interest in injecting water into the H2ICE as an alternative to augment the EGR effect. In this study, the spark ignition (SI) single-cylinder engine equipped with two direct injectors was used to evaluate the hydrogen and the water dual direct injection combustion system. This system involved the direct injection of hydrogen using a wall-guided gasoline direct injector and the direct injection of water into the combustion chamber using a diesel injector. This approach utilizes the
Kim, Kiyeon, Lee, Seungil, Kim, Seungjae, Lee, Seunghyun, Min, Kyoungdoug, Oh, Sechul, Son, Jongyoon, Lee, Jeongwoo
Combustion of Hydrated Ethanol and Gasoline RON95 Ultra-High Pressure Direct Injection in Optical Access SI Engine2024-36-015212/20/2024
High and ultra-high pressure direct injection (UHPDI) can enhance efficiency gains with flex-fuel engines operating on ethanol, gasoline, or their mixtures. This application aims to increase the engine’s compression ratio (CR), which uses low CR for gasoline due to the knocking phenomenon. This type of technology, involving injection pressures above 1000 bar, permits late fuel injection during the compression phase, preventing auto-ignition and allowing for higher compression ratios. UHPDI generates a highly turbulent spray with significant momentum, improving air-fuel mix preparation, and combustion, resulting in even greater benefits while minimizing particulate matter emissions. This study aims to develop ultra-high-pressure injection systems using gasoline RON95 and hydrated ethanol in a single-cylinder engine with optical access. Experimental tests will be conducted in an optically accessible spark ignition research engine, employing thermodynamic, optical, and emission results
Malheiro de Oliveira, Enrico R., Mendoza, Alexander Penaranda, Martelli, Andre Luiz, Dias, Fábio J., Weissinger, Frederico F., dos Santos, Leila Ribeiro, Lacava, Pedro Teixeira
Experimental Investigation on Combustion Strategy of Light Duty GCI Fueled High Reactivity Gasoline Fuel2024-01-428211/5/2024
Diesel engines are largely used as power units with high fuel efficiency. Conversely, they have an adverse impact on the environment and human health as they emit high NOx and particulate matter emissions. As more stringent regulations for emissions are introduced, low temperature combustion strategy such as Gasoline Compression Ignition evolved and demonstrated the potential to reduce the particulate matter and NOx emissions by operating engines under a Partially Premixed Combustion mode. Therefore, a 0.55 mm single cylinder engine (Gasoline Direct Injection), was tested over range of engine loads with constant speed (1500 rpm) using RON80 without oxygenates. Different operating parameters such as injection, exhaust gas recirculation (EGR) etc. were used to control combustion phasing and mixture stratifications. At low loads, rebreathing of hot exhaust gas produced low levels of NOx and smoke emissions. It reduced NOx by 60% and smoke levels below 0.20 FSN when it is coupled with low
Qahtani, Yasser Al, Sellnau, Mark, Yu, Xin
Prediction of WLTC Mode Drive Fuel Consumption for Vehicles Running on Blended Gasoline2024-01-429111/5/2024
It is becoming increasingly clear that research into alternative fuels, including drop-in fuels, is essential for the continued survival of the internal combustion engine. In this study, the authors have evaluated olefinic and oxygenated fuels as drop-in fuels using a single-cylinder engine and considering fuel characteristic parameters. The authors have assessed thermal efficiency by adding the EGR amount from 0 to the maximum value that allows stable combustion at the theoretical air-fuel ratio. Next, we attempted to predict fuel efficiency for three types of passenger cars (Japanese small K-car N/A, K-car T/C, and Series-HV) by changing the fuels. We created a model in OpenModelica to estimate fuel efficiency during WLTC driving. The results indicated that fuel economy could potentially be improved by adding an olefin fuel that burns stably even with a large amount of EGR and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was
Moriyoshi, Yasuo, Kuboyama, Tatsuya, Kawakami, Sota, Wang, Zhiyuan
Powertrain NVH Optimization of Single Cylinder CI Engine2024-28-000110/17/2024
With increasing pursuit for comfort in mobility NVH characteristics are becoming more important than ever. Achieving a benchmark beating NVH behavior involves optimizing source, transfer paths as well as target location mechanical characteristics. In ICE vehicles, powertrain accounts for major source of noise and vibration. This work encompasses NVH refinement strategies for a single cylinder compression ignition engine. The work starts with setting target values for NVH characteristics based on competitive benchmark data analysis. A complete development strategy involving extensive testing and CAE correlation is presented here. Contribution analysis in component level for optimization of NVH behavior is carried out employing NVH testing in anechoic chamber supported by CAE simulations. This paper describes the later phases of the entire development process which are decisive for engine NVH; the combustion and mechanical development phase and the NVH development and refinement phase
Kunde, Sagar, Thakur, Sunil, Wagh, Sachin, Bhangare, Amit, Prabhakar, Shantanu
Influence of Lube Oil and Fuel Additives on the Particulate Raw Emission Behavior of Gasoline Engines04-18-01-000410/3/2024
The aim of this work was to investigate the influence of different combinations of engine oil and oil additive as well as additivated and unadditivated fuel on particulate emissions in gasoline engines. To accomplish this, load, speed, and type of oil injection were varied on a single-cylinder engine, and the influence on particle number concentration and size distribution were evaluated. The tests were supplemented by an optical investigation of their in-cylinder soot formation. The investigation of fuel additives showed no significant differences compared to the reference fuel without additives. However, in the case of oil additives, detergents led to a significant increase in the number of particles in the <20 nm range. This effect occurred when used as both a single additive and a component in the standard engine oil. While viscosity improvers also lead to a measurable, but less pronounced, increase in the particle number concentration, no significant influence can be determined
Böhmeke, Christian, Heinz, Lukas, Wagner, Uwe, Koch, Thomas
Numerical and Experimental Analysis of Dual Fuel Hydrogen/Diesel Combustion at Varying Engine Speed on a Single Cylinder Engine2024-24-00449/18/2024
In this study, dual fuel combustion process has been investigated numerically and experimentally in a single cylinder research engine. Two engine speeds have been investigated (1500 and 2000 rpm) at fixed BMEP of 5 bar for both engine speeds. For each engine speed two operating points have tested with and without EGR (Exhaust Gas Recirculation). The hydrogen has been injected in the intake manifold in front of the tumble intake port inlet and a small amount of diesel fuel has been introduced directly in the cylinder through two injections strategy: one pilot injection occurring Before Top Dead Center (BTDC) and one main occurring around the Top Dead Center (TDC). The dual-fuel combustion model in GT-SUITE has been used first to calibrate the combustion model by using the Three Pressure Analysis (TPA) model. This step allows the calibration of the combustion model to predict in-cylinder combustion processes. Simulations have been performed at varying mass distribution of injected diesel
Maroteaux, Fadila, SEBAI, Salim, Mancaruso, Ezio, Rossetti, Salvatore, Schembri, Patrick, Radja, Katia, Barichella, Arnault
Numerical Investigation of Injection and Mixture Formation in Hydrogen Combustion Engines by Means of Different 3D-CFD Simulation Approaches2024-01-30077/2/2024
For the purpose of achieving carbon-neutrality in the mobility sector by 2050, hydrogen can play a crucial role as an alternative energy carrier, not only for direct usage in fuel cell-powered vehicles, but also for fueling internal combustion engines. This paper focuses on the numerical investigation of high-pressure hydrogen injection and the mixture formation inside a high-tumble engine with a conventional liquid fuel injector for passenger cars. Since the traditional 3D-CFD approach of simulating the inner flow of an injector requires a very high spatial and temporal resolution, the enormous computational effort, especially for full engine simulations, is a big challenge for an effective virtual development of modern engines. An alternative and more pragmatic lagrangian 3D-CFD approach offers opportunities for a significant reduction in computational effort without sacrificing reliability. The detailed and the lagrangian approach are both validated against optical measurements
Schmelcher, Robin, Kulzer, Andre, Gal, Thomas, Vacca, Antonino, Chiodi, Marco
Effect of Ethanol and Iso-Octane Blends on Isolated Low-Temperature Heat Release in a Spark Ignition Engine04-17-03-00165/17/2024
Low-temperature heat release (LTHR) is of interest for its potential to help control autoignition in advanced compression ignition (ACI) engines and mitigate knock in spark ignition (SI) engines. Previous studies have identified and investigated LTHR in both ACI and SI engines before the main high-temperature heat release (HTHR) event and, more recently, LTHR in isolation has been demonstrated in SI engines by appropriately curating the in-cylinder thermal state during compression and disabling the spark discharge. Ethanol is an increasingly common component of market fuel blends, owing to its renewable sources. In this work, the effect of adding ethanol to iso-octane (2,2,4-trimethylpentane) blends on their LTHR behavior is demonstrated. Tests were run on a motored single-cylinder engine elevated inlet air temperatures and pressures were adjusted to realize LTHR from blends of iso-octane and ethanol without entering the HTHR regime. The blends were tested with inlet temperatures of 40
White, Samuel Philip, Bajwa, Abdullah Umair, Leach, Felix
TOC99-06-02-0TOC4/15/2024
TOC
Tobolski, Sue
Next Generation High Efficiency Boosted Engine Concept2024-01-20944/9/2024
This work represents an advanced engineering research project partially funded by the U.S. Department of Energy (DOE). Ford Motor Company, FEV North America, and Oak Ridge National Laboratory collaborated to develop a next generation boosted spark ignited engine concept. The project goals, specified by the DOE, were 23% improved fuel economy and 15% reduced weight relative to a 2015 or newer light-duty vehicle. The fuel economy goal was achieved by designing an engine incorporating high geometric compression ratio, high dilution tolerance, low pumping work, and low friction. The increased tendency for knock with high compression ratio was addressed using early intake valve closing (EIVC), cooled exhaust gas recirculation (EGR), an active pre-chamber ignition system, and careful management of the fresh charge temperature. Engine weight reduction measures were implemented throughout the engine system making use of composite materials, advanced manufacturing techniques, and architectural
Shelby, Michael H., Case, Mark E., Chesney, Lynn A.
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