Browse Topic: Environment

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Method for externally controlled availability of lubricating oil in internal combustion engines.2025-01-0302To be published on 07/02/2025
Reduced emissions in internal combustion engines (ICE) are a key component in reaching green-house-gas and pollutive emissions regulations. With increased effort, clean and efficient burning combustion cycles are being developed. With the need of even more efficient engines the friction of ICE engines plays an increasing role in engine efficiency. Also, ingress of lubricating oil into the combustion chamber is a source of particle emissions. Increased optimization to reduce parasitic drag in the piston assembly such as reduced ring pre-tension ore thinner grade oils further increase oil ingress into the combustion chamber with the result of increased particle emissions. The transport mechanisms of oil ingress into the combustion chamber therefore the topic of current research. Specially developed research engines with a vertical optical window have big potentials to visualize phenomena of the oil behavior inside the piston assembly in internal combustion engines. Therefore, these
Stark, Michael, Fellner, Felix, Härtl, Martin, Jaensch, Malte
Technical Paper
Optimized Cabin Heating Strategy for Battery Electric CEP Vehicles2025-01-0263To be published on 07/02/2025
Electromobility is gaining significance in the CEP (Courier, Express, and Parcel) sector, as parcel service providers increasingly rely on zero-emission vehicles to improve their CO2 balance. A general disadvantage of electric vehicles is the reduced range under cold operating conditions due to the higher energy demand for cabin heating. Another CEP-specific effect which affects the energy demand and thermal cabin comfort is the frequent door opening during the parcel delivery. Additionally, the vehicle cabin cools down during the driver’s absence because the cabin heating is turned off. Despite an acceptable level of thermal comfort must be maintained during the driving phases. This paper proposes an optimization-based strategy for the cabin heating of battery electric CEP vehicles. The objective is to maximize the cabin temperature during the driving phases compared to a baseline heating strategy while maintaining a desired energy consumption. For this purpose, a nonlinear model
Rehm, Dominik, Krost, Jonathan, Meywerk, Martin, Czarnetzki, Walter
Technical Paper
In Situ Observation of Different Soot Layers in a Model Filter Channel During Its Regeneration2025-01-0312To be published on 07/02/2025
To keep the air clean, wall-flow particulate filters are predominantly used in the exhaust gas after-treatment systems of combustion engines to remove reactive soot and inert ash particles. These filters consist of parallel porous channels with alternately closed ends, effectively separating particles by forming a layer on the filter surface. However, the particulate layer increases the pressure drop, requiring periodic regeneration. During regeneration, soot oxidation breaks up the particulate layer, while resuspension and transport of individual agglomerates may occur. These phenomena are influenced by gas temperature and velocity, as well as dispersity and the reactivity of the soot particles. Sustainable fuels can produce different types of soot with different reactivities and dispersities, therefore this study focuses on the influences of soot dispersity and reactivity by varying the reactive particle system. A model wall-flow filter channel is used for the investigation, enabling
Desens, Ole, Hagen, Fabian P., Meyer, Jörg, Dittler, Achim
Technical Paper
Application of Sustainable Aviation Fuels in CI Aviation Engines: In-Flight Investigations2025-01-0317To be published on 07/02/2025
To achieve a significant reduction in net CO₂ emissions in the aviation sector, sustainable aviation fuels (SAFs) are considered a key factor. Current research efforts are therefore focused on SAFs, which exhibit properties that differ from conventional kerosene, particularly in aspects critical to compression-ignition (CI) engines, such as cetane number, evaporation behavior or lubricity. These differences necessitate dedicated investigations to assess their suitability and performance in such engines. However, real operating conditions — such as intake air- and exhaust- pressure levels during flight — cannot be fully replicated on standard engine test benches. For this reason, real flight experiments were conducted to address these limitations. Notably, this work marks the first instance of in-flight testing of SAFs in CI aviation engines, constituting a significant milestone in this research area. In the course of these investigations, ASTM D7566 Annex A2-compliant HEFA
Kleissner, Florian, Reitmayr, Christian, Hofmann, Peter
Technical Paper
Prediction of hazardous gaseous emissions from a gasoline engine during cold starts using machine learning methods2025-01-0321To be published on 07/02/2025
Internal combustion engines generate higher exhaust emissions of hazardous gases during the initial minutes after engine start. Experimental data from a state-of-the-art turbo-charged 3-cylinder, 999 cc gasoline engine are used to predict cold start emissions using two Machine Learning (ML) models: a Multilayer Perceptron (MLP) which is a fully connected neural network and an Encoder-Decoder Recurrent Neural Network (ED-RNN). Engine parameters and various temperatures are used as input for the models and NOx, CO, and unburned hydrocarbon (UHC) emissions are predicted. The dataset includes time series recordings from the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC) and four Real Diving Emissions (RDE) cycles at ambient and initial engine temperatures ranging from -20 °C to +23 °C. In total, 21 cases are considered, consisting of eight different ambient temperatures and five distinct driving cycles. Each case consists of a sequence of 2500 samples taken at 5 Hz. The
Mangipudi, Manoj, Denev, Jordan A., Bockhorn, Henning, Trimis, Dimosthenis, Koch, Thomas, Debus, Charlotte, Götz, Markus, Zirwes, Thorsten, Hagen, Fabian P., Tofighian, Hesam, Wagner, Uwe, Braun, Samuel, Lanzer, Theodor, Knapp, Sebastian M.
Technical Paper
Effect of Gasoline Component on Fuel Economy of WLTC Drive with EGR and Lean Combustion2025-01-0305To be published on 07/02/2025
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 the EGR or air from 0 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 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 or air and an oxygen fuel whose octane number increases. It was observed that the fuel economy improvement rate was particularly
Moriyoshi, Yasuo, Xu, Fuguo, Wang, Zhiyuan, Tanaka, Kotaro, Kuboyama, Tatsuya
Technical Paper
Life-Cycle Assessment of a Composite vs. a Metallic Bipolar Plate for Fuel Cell Applications: More Sustainable while Maintaining Same Performance Standards?2025-01-0298To be published on 07/02/2025
Faced with one of the greatest challenges of humanity – climate change – the European Union has set out a strategy to achieve climate neutrality by 2050 as part of the European Green Deal. Life Cycle Assessment (LCA), which among other aspects identifies climate change effects, is an important tool to assess the environmental characteristic of sustainable technologies or products to fulfill this ambitious target. In this context, research is presented that examines the ecological sustainability impacts of a metallic vs a composite bipolar plate made of innovative graphite-compound based foils. A bipolar plate is a central component of the fuel cell stack to ensure efficiency and durability. For this purpose, a LCA was performed for both bipolar plate materials. This assessment follows the methodology of DIN EN ISO 14040/44 and the EU Product Environmental Footprint framework. Focusing on cradle-to-gate system boundary conditions, the research focuses on the manufacturing processes with
van Sloun, Andreas, Schroeder, Benedikt, Kexel, Jannik, Schmitz, Maximilian, Balazs, Andreas, Walters, Marius, Koßler, Silas, Pischinger, Stefan, Joemann, Michael
Technical Paper
Optimization of Metallic Substrate by 1D simulations to fulfill High Power Cold Start Conditions2025-01-0308To be published on 07/02/2025
The future of the internal combustion engine is strictly related to his capability to have Life Cycle Emission comparable to the pure Battery Electric Vehicles. To achieve this goal, it will be necessary not only to have carbon free fuels but also to increase the hybridization of the powertrain in order to have lower fuel consumption. On the other hand, it will be necessary to reduce to almost zero any further emissions of pollutants. For this reason, highly sophisticated exhaust aftertreatment must be developed. One particular use case is the so-called High-Power Cold Start. This can occur for the Plug-In Hybrid Electric Vehicles when the transition from pure electric drive to ICE assisted drive happens during high load request, for example an acceleration on the freeway ramp. This use case has been evaluated by CARB and in many other works. Nevertheless, in this particular paper, the Authors would like to investigate which Metallic Substrate Technology fits better during a HPCS. This
Montenegro, Gianluca, Onorati, Angelo, Della Torre, Augusto, Marinoni, Andrea, Pace, Lorenzo, Konieczny, Katrin, Laurell, Mats, Klövmark, Henrik
Technical Paper
Methodology for Fast-Running, Time-Resolved Simulation of Non-Exhaust Particle Emissions from Brake Wear Abrasion2025-01-0275To be published on 07/02/2025
Non-exhaust particle emissions, particularly those generated by brake wear, are a significant source of fine particulate matter in urban environments. These emissions contribute to air pollution and pose serious health risks, particularly in densely populated areas. While vehicle exhaust emissions have been extensively studied and regulated, the contribution of non-exhaust sources, including brake wear, remains a critical factor in air quality management. This paper presents a novel methodology for fast-running, time-resolved simulation of non-exhaust particle emissions, specifically those from brake wear abrasion. A 3D CFD model computes the turbulent flow field around the disc brake. The resulting information on the convective air cooling is applied as boundary conditions on a 3D thermal model. This thermal simulation setup is compared and verified with experimental data from literature. The 3D numerical models produce data and boundary conditions for an efficient 1D numerical
Herkenrath, Ferris, Lückerath, Moritz, Günther, Marco, Pischinger, Stefan
Technical Paper
Effects of Double Injection Strategy in a Diesel-Ammonia Dual-Fuel Engine2025-01-0206To be published on 06/16/2025
This study investigates the application of a double injection strategy in a single-cylinder marine diesel-ammonia dual-fuel engine retrofitted for experimental analysis. Diesel micro-pilot (MP) injection was used to ignite ammonia combustion, with diesel and ammonia injected separately into the cylinder through dedicated injectors. The first MP injection timing was fixed at -20 CAD before ammonia injection timing, and both early and late double MP injection strategies were implemented to evaluate their effects on ammonia combustion, engine performance, and exhaust emissions. Under all conditions, the ammonia injection timing remained constant. Early double injection strategies, with the second MP injection occurring before the first, enhanced premixed diesel combustion by raising in-cylinder temperature and pressure. However, this early heat release was ineffective for ammonia evaporation and combustion due to poor timing alignment. In contrast, late double injection strategies, with
Park, Chansoo, jang, Ilpum, Park, Cheolwoong, Kim, Minki, Park, Gyeongtae
Technical Paper
Techno-Economic Analysis of an Integrated E-Methanol Production Plant Utilizing First and Second Generation Biomass Resources2025-01-0182To be published on 06/16/2025
Building upon foundational research utilizing Aspen Plus modeling for e-methanol production from sugar cane and sugar beet biomass, this study advances by incorporating a comprehensive techno-economic assessment (TEA) of an integrated e-methanol production system. The established integrated system converts biomass into ethanol through fermentation and synthesizes e-methanol using both captured CO2 and syngas derived from biomass residue gasification. The approach optimizes dual utilization of CO2 and biomass thereby fostering a circular carbon economy. The TEA quantifies capital expenditures (CAPEX), operational expenditures (OPEX), and levelized costs of energy (LCOE), providing a detailed economic analysis of the potential for commercializing e-methanol. Additionally, a sensitivity analysis is conducted to evaluate the impact of variable factors such as feedstock prices, process yields, and energy costs on the economic outcomes. This sensitivity analysis is crucial for understanding
Fernandes, Renston Jake, Shakeel, Mohammad Raghib, Nguyen, Ducduy, Im, Hong G., Turner, James W.G.
Technical Paper
Ultra low engine-out particle emissions from gas fuelled engines through lube oil formulation: evidence from an experimental campaign and machine learning based approach for data analysis2025-01-0249To be published on 06/16/2025
The transportation industry has undergone major changes in the past years, switching from traditional fossil fuels supply to alternative and cleaner ones. This is true especially in the field of heavy-duty (HD) engines, where Compressed Natural Gas is currently the most valid substitute of Diesel for off-road and transport applications. The upcoming stringent limits on sub-23 nm particles emissions will regard also gas fuelled engines; their compliance with future regulations requires great technological effort. The present work is addressed to the investigation of strategies to reduce particles emitted from HD gas engines. In particular, focus of the activity is the study of the potentiality offered by lubricant oils formulation in particle number (PN) emissions control. Indeed, particle emissions from gas engines come mainly from the combustion of lubricant oil leaking into the engine combustion chamber. An extensive experimental campaign on an HD SI engine with different lubricants
Guido, Chiara, Napolitano, Pierpaolo, Arpino, Alfonso, Cerbone, Daniele, Di Domenico, Davide, Beatrice, Carlo, Bozza, Fabio
Technical Paper
Investigating lubricants base oils reactivity in ammonia/hydrogen engines via accelerated aging2025-01-0240To be published on 06/16/2025
As a carbon-free molecule, ammonia is more and more considered as a relevant fuel for long distance and off-road applications. However, this gas has different combustion characteristics compared to conventional fuels, challenging the suitability of lubricants to such engines. In this work, the evolution of lubricants under conditions mimicking ammonia combustion was assessed. Mineral and polyester lubricant base oils were exposed to oxygen, nitrogen oxides, and ammonia in a pressurized reactor under stirring. Oil aliquots were sampled at regular intervals, and characterized using Fourier Transform Infrared Spectroscopy (FTIR), viscosity and total oxygen and nitrogen contents measurements. Exposure to air containing nitrogen oxides resulted in quicker accumulation of oxidation products compared to neat air, for both the mineral and complex polyester base oil. Besides, exposure to gaseous ammonia in air resulted in a slower oxidation rate for both oils, compared to neat air. A global
Doncoeur, Carole, Giarracca, Lucia, Cologon, Perrine, Rousselle, Christine
Technical Paper
Combustion and emission characteristics of marine Ammonia-Diesel dual fuel single-cylinder engine with MP injector change2025-01-0235To be published on 06/16/2025
Recently, as regulations on greenhouse gas emissions due to global warming have tightened, there has been growing interest in engines that use environmentally friendly fuels. In this context, ammonia is gaining attention as a potential alternative to fossil fuels in the future. However, due to the unique fuel characteristics of ammonia compared to traditional fuels, research is being conducted on using diesel as an ammonia ignition source. In this study, combustion and exhaust characteristics were compared according to the characteristics of micro-pilot diesel injectors in the marine ammonia-diesel dual fuel single-cylinder engine. Various injectors with different hole numbers and sizes were examined (Injector A: more holes and larger size, Injector B: fewer holes and smaller size). To maintain a constant energy ratio between ammonia and diesel at a steady load, the injection duration was adjusted, and the MP injection timing varied in 5 CAD intervals to evaluate performance and
Jang, Ilpum, Park, Cheolwoong, Kim, Minki, Park, Chansoo, Kim, Yongrae, Park, Gyeongtae, Lee, Jeongwoo
Technical Paper
A Numerical approach to predict UREA crystal deposition in the exhaust system2025-01-0233To be published on 06/16/2025
The stringent emission regulations for NOx pollutants force further development of automotive exhaust aftertreatment systems with selective catalytic reduction. Crystal free operation is one of the major requirements for automotive exhaust aftertreatment systems with selective catalytic reduction using urea water solution as NH3carrier fluid. A high injection rate of UWS or unfavorable operating such as high injection rate or low exhaust temperatures conditions may lead to formation of solid deposits. Both may lead to formation of solid deposits which increase backpressure and impair ammonia uniformity. Crystals forming on the injector tip may fail the emissions test and will also need frequent service to the vehicle, which will be stinging point to the customer. To optimize the exhaust path, a reliable & a faster numerical simulation approach was considered. An initial assessment of the spray deposit and the correlation with the experiment is initially studied to understand the
Krishnan, Karthikeyan N.
Technical Paper
Overview of Indian Government Policies, Regulations and Automotive Company Strategies toward Net-zero Emissions2025-01-0184To be published on 06/16/2025
The automotive sector in India is undergoing a transformation, driven by government policies and regulations aimed at achieving net-zero carbon emissions. In alignment with global climate goals, the Indian government has set ambitious targets to reduce greenhouse gas emissions, with a focus on promoting Electric Vehicles (EVs) and Hydrogen Fuel Cell Vehicles (FCVs). Initiatives like the Faster Adoption and Manufacturing of Hybrid and Electric Vehicles (FAME) Scheme, along with tax incentives, subsidies, and charging infrastructure development, are designed to accelerate the adoption of cleaner vehicles. The introduction of stricter emission standards and the National Electric Mobility Mission Plan (NEMMP) further underscores the push toward sustainable mobility. In response, Indian automotive companies are shifting strategies to align with these government directives. Major players are significantly increasing investments in EV technology, focusing on enhancing battery performance
Patil, NIKHIL, Saurabh, Saurabh, Gawhade, Ravikant, Bhardwaj, Rohit, Gadve, Dhananjay, Amancharla, Naga Chaithanya
Technical Paper
Analysis of Combustion Characteristics of a Small 2-Stroke Opposed Piston Engine Using an Optically Accessible Engine and Numerical Analysis2025-01-0223To be published on 06/16/2025
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, Iijima, Akira, Liu, Jinru, Otaki, Yusuke, Watanabe, Sou, Okawara, Ikumi
Technical Paper
Performance evaluation of a turbocharged spark-ignition engine operating on various H2-gasoline blend ratios2025-01-0227To be published on 06/16/2025
The transportation sector's significant contribution to global carbon emissions has intensified the search for cleaner alternative fuels, with hydrogen (H2) emerging as a promising candidate. Its high energy density, clean combustion characteristics, and compatibility with existing internal combustion engine (ICE) technology make it particularly attractive as an alternative to conventional fuels. While pure H2-fuelled ICEs still face numerous technical challenges, H2-gasoline dual fuel systems present a practical transitional approach, offering the benefits of hydrogen combustion while utilizing existing fuelling infrastructure. This study presents an experimental investigation of a turbocharged spark-ignition (SI) engine operating on various H2-gasoline fuel blends. The port-injection engine, which serves as the core test unit in UTM-LoCARtic's facility, has been extensively tested under various operating conditions (steady-state, transient, and drive cycles) and different
Rajoo, Srithar
Technical Paper
Commercial vehicles exhaust front pipe reliability improvement through virtual simulation and experimental Validation2025-01-0209To be published on 06/16/2025
Exhaust front pipe is an important structural component of any commercial vehicle. It requires to be reliable enough to ensure leak proof flow of exhaust gases into exhaust after treatment system and at the same time it must withstand engine as well as frame vibrations. To isolate engine and frame vibrations, front pipe is equipped with flex connector having ability to withstand several displacements at certain frequency level. The position of flex connector with respect to engine crank axis plays an important role in its structural reliability during its services life. This paper presents a comparison between existing design with horizontal position versus modified design with vertically positioned flex connector evaluated with excitation of 25 mm lateral displacement at 8 Hz frequency and a correlation has been established between virtual simulation and experimental validation. Virtual and experimental results conclude that there is 70% of increase in front pipe life when flex
Paroche, Sonu, Chandel, Kushal, NAMDEV, AKHILESH, Jain, Shailendra, Patil, Keyur
Technical Paper
Development of After-treatment Systems and Control Strategy for a Hybrid-dedicated Homogeneous Lean Burn Engine2025-01-0217To be published on 06/16/2025
Lean-burn gasoline engines can improve fuel economy thanks to the higher specific heat ratio of the mixture and the reduced cooling loss during the combustion process. In addition, when combined with hybrid technology, the technology can achieve more synergies by overcoming obstacles such as limited operating conditions. However, the challenge of this technology is to reduce exhaust emissions to a level suggested by future stringent regulations. In lean-burn gasoline engines, nitric oxide (NOx) emissions are difficult to convert using conventional three-way catalysts (TWCs). Therefore, developing an effective NOx after-treatment system has been a key technology in the development of lean-burn engines. In addition, hydrocarbon (HC) emissions are also challenging because they increase under lean combustion conditions, while the lower exhaust temperature under lean conditions makes them hard to oxidize. Therefore, a catalyst technology capable of effectively converting HC, even at a low
Oh, Heechang, Lee, Jonghyeok, Sim, kiseon, Lim, SeungSoo, Park, Jongil, Park, Minkyu, Kang, Hyunjin, Han, Donghee, Lee, Kwiyeon, Song, Jinwoo
Technical Paper
Comparison of HRD and Petro Diesel in Industrial Engine Applications2025-01-0243To be published on 06/16/2025
Renewable fuels are seen as a key enabler on the path to a lower carbon future. A low greenhouse gas fuel of particular interest is hydrotreated renewable diesel (HRD), also known as hydrotreated vegetable oil (HVO). HRD is of interest because it is a drop-in replacement to existing petroleum fuels used in diesel engines. An experimental investigation was undertaken to evaluate combustion characteristics of HRD versus a standard petroleum diesel. The work was carried out using a 2.5-liter fully instrumented single-cylinder research engine. This engine was chosen because it provides a very precise view of the difference in combustion and emissions of the fuels. Results represent the difference in combustion characteristics of the fuels, rather than potential differences in engine performance seen in a production engine, as each particular engine model will react a bit differently to the changes in combustion. The engine was operated according to three ISO 8178-4 test cycles: C1, D2, and
Bardell, Michael, Abi-Akar, Hind, Seiler, Patrick, Nash, Brady, McMahon, Donna, Ioannou, Marios
Technical Paper
numerical investigation into the combustion and emission characteristics of ammonia direct injection mechanism2025-01-0241To be published on 06/16/2025
Ammonia is an attractive option because of its relatively low greenhouse gas (GHG) emissions, high energy density, competitive cost, and ubiquitous infrastructure for manufacturing, storage, and distribution. In this work, the optimum combustion characteristics are investigated to propose an efficient ammonia engine for future investigation. The effects of ammonia addition on diesel combustion characteristics were numerically investigated in a CI engine. The investigation was conducted by structured 3D CFD modeling to analyze the combustion characteristics. The validation of the boundary condition was compared to the designed experimental ammonia engine. The direct injection timing of 10o-50oBTDC and injection pressure 300-800 bar was proposed to identify the optimum autoignition characteristics. The equivalence ratios 1, 0.75, 0.5, and 0.25 were used in order to analyze the high cetane number characteristics and the air-fuel ratio.
setiawan, ardhika
Technical Paper
Development of Simple Models for Performance Estimation of an Ammonia Fueled Spark Ignition Engine2025-01-0238To be published on 06/16/2025
Achieving a carbon neutral society, eliminating greenhouse gas emissions is one of the most important issues. Ammonia is expected as a carbon free energy source. However, the laminar burning velocity of ammonia is much slower than hydrocarbons. Then, it is common to reform a portion of ammonia and use the ammonia/hydrogen mixture as a fuel. In this research, the operating characteristics of spark-ignition engine fueled with ammonia reformed gas is investigated and construct model estimating engine performance. A four-stroke single cylinder spark-ignition engine with a stroke volume of 212 cm3 is used. Total equivalence ratio is kept at unity and ammonia equivalence ratio is changed. Also, ammonia reformed gas is simulated as follows: ammonia and hydrogen are supplied from high pressure cylinders and injected by using automobile gaseous fuel injectors. Nitrogen is supplied from high pressure cylinder and supplied 1/3 of the molar ratio to hydrogen by a mass flow controller. The test
Ichikawa, Aya, Ogura, Yuto, Yanaoka, Kazuki, Gonzalez Palencia, Juan, Kambara, Shinji, Araki, Mikiya
Technical Paper
Evaluation of Several Jet Fuels under Compression-ignition Operation on Thermal Efficiency, NOx, Particulate Matter, and Particle Size Distribution2025-01-0244To be published on 06/16/2025
Alternative fuels such as Fischer-Tropsch Synthesized Paraffinic Kerosene (FT-SPK) and Catalytic Hydrothermal Conversion Jet (CHCJ) are among those important sustainable aviation fuels (SAFs) for future transportation. However, these alternative fuels often vary in their fuel characteristics, which depend on feedstock and fuel production processes. Therefore, a detailed analysis of combustion, emissions, and efficiency of these alternative fuels must be performed under controlled experiments to understand the impact of fuel properties and operating conditions. Using a single-cylinder research engine (SCRE), extensive operating conditions were performed to realize any difference in performance that can be fundamentally understood by fuel properties (e.g., cetane number, heat of combustion, and density) of these fuels in comparison with Jet-A. The experimental setup includes high-speed data acquisition for combustion analysis and gaseous and solid emissions benches for nitrogen oxides
Cung, Khanh, Miganakallu Narasimhamurthy, Niranjan, Khalek, Imad, Hansen, Greg
Technical Paper
Evaluating the Impact of Displacing Injected Gasoline with Aspirated Ammonia in a Direct Injection Spark Ignition Engine2025-01-0226To be published on 06/16/2025
Replacing fossil fuels with renewable ammonia could provide a crucial step towards the decarbonisation of transport sectors. However, many challenges remain in utilising ammonia within combustion systems: the volumetric energy density of ammonia is significantly lower than that of gasoline, exposure to ammonia (including ammonia slip) can be detrimental to human health, and the production of emissions, including unregulated emissions (such as N2O), from ammonia combustion can be catastrophic for the environment if not treated appropriately. Therefore, there is a need to determine the efficacy of ammonia as a fuel for internal combustion engines and the impact on the efficiency of energy release and the resulting exhaust emissions. A modern spark ignition engine was modified such that ammonia was aspirated through the engine intake air to incrementally displace engine gasoline and maintain a constant work output. It was found that displacing the fuel energy supplied by direct injected
Sivaranjitham, Annaniya Mitchell, Hellier, Paul, Ladommatos, Nicos, Millington, Paul, Alcove Clave, Silvia
Technical Paper
Thermal efficiency improvement and emission reduction of methanol spark ignition engine using lean-burn strategy2025-01-0224To be published on 06/16/2025
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. In this study, experiments were conducted on a single-cylinder engine to examine the combustion and emission characteristics under varying excess air ratios and injection timings. The results showed that the highest thermal efficiency was achieved at the highest excess air ratio, despite the lowest combustion efficiency and the longest burn duration. This outcome highlights that a larger air mass reduces heat loss and pumping loss. Furthermore, NOx emissions decreased due to the reduction in in-cylinder temperatures. However, HC emissions increased as a result of the decline in combustion efficiency
Lee, Seungwon, Kim, Hyunsoo, Hwang, Joonsik
Technical Paper
Impact of reduced catalytic activity on passive regeneration of catalyzed diesel particulate filters2025-01-0185To be published on 06/16/2025
Oxidation catalysts can greatly improve the regeneration efficiency of diesel particulate filters (DPF) by providing sufficient levels of NO2 for low-temperature soot oxidation. As for other automotive catalysts, catalyzed DPFs (CDPFs) are subject to aging effects, resulting in decreased performance of the NO oxidation reaction. The life span of CDPFs generally only considers the elevated back pressure as a consequence of the accumulation of ash. However, with reduced catalytic activity and impaired functionality of the regeneration process there is a risk of premature replacement of the CDPF or accumulation of soot above critical levels. In this study, a new exhaust aftertreatment system has been developed to accommodate sub-scale catalysts and DPFs for testing with full-size heavy-duty engines. The modified exhaust aftertreatment system was used together with a rig for accelerated soot and ash loading to assess the impact of CDPF aging on regeneration performance under real
af Ugglas, Samuel, Ersson, Anders, Yao, Dawei, Pettersson, Lars, Kusar, Henrik
Technical Paper
Life Cycle Assessment of Hydrogen Production via Steam Methane Reforming: Comparative Analysis of Steam and Electricity as Co-Products2025-01-0181To be published on 06/16/2025
This research presents a numerical analysis of the environmental impacts associated with using hot steam as a co-product in hydrogen production through Steam Methane Reforming (SMR) of renewable gas sources. As hydrogen production technology advances rapidly, reducing emissions and addressing environmental concerns, particularly greenhouse gas (GHG) emissions, have become essential. This study examines the SMR process with a focus on the environmental effects of utilizing hot steam as a co-product for electricity generation or facility heating. The analysis evaluates renewable feedstocks, including landfill gas, animal waste, food waste, and wastewater sludge, to determine their viability for sustainable hydrogen production. Key pollutants, such as carbon monoxide and nitrogen oxides, along with GHGs, are assessed to identify the most environmentally advantageous feedstock options. This work aims to provide insights promote sustainable hydrogen production practices.
Rosyadi, Ahmad Adib
Technical Paper
Catalyzing the Hydrogen Economy: Designing Low-Cost Refueling Modules for India's Mobility Revolution2025-01-0187To be published on 06/16/2025
The likely depletion of fossil fuel reserves in the next fifty years and growing environmental concerns caused by petroleum fuel-based vehicles highlight the urgent need for sustainable alternatives. India, a developing country, requires a significant amount of energy to sustain its growth, most of which is imported. Hydrogen is one of the cleanest fuels and offers sustainable pathways to a low-carbon future. The government of India has already launched a Green Hydrogen mission and has set up a very ambitious target for 2030. However, the absence of adequate refueling infrastructure is a significant blockade to India's widespread adoption of hydrogen-powered vehicles. The mobile hydrogen refueling station (MHRS) is a flexible system that enables lower initial capital costs than fixed hydrogen refueling stations and allows for the gradual build-up of hydrogen mobility fleets. Such a system could be very useful in India, and it integrates advanced safety features, including hydrogen leak
Mathur, Animesh, Nayak, Ajay, Kumar, Naveen
Technical Paper
Optimization of the lubricating oil composition to reduce emissions from hydrogen engines2025-01-0212To be published on 06/16/2025
The decarbonization of the transport sector has become a priority for governmental authorities and industrial stakeholders alike, driving regulatory measures and innovation in powertrain technologies. Among the innovative solutions, hydrogen combustion engines have gained significant attention due to their customization to diverse applications, including heavy-duty vehicles, passenger cars, generators, and even two- and three-wheelers. Hydrogen combustion, characterized by high ignitability, rapid flame speed, soot-free operation, and water as a combustion by-product, introduces distinct challenges for engine lubrication. These unique characteristics require the development and adaptation of lubricant formulations to ensure optimal engine performance and durability. Specifically, tailored lubricants play a vital role in addressing four key challenges: pre-ignition, particulate emissions, water contamination, and wear protection. This study investigates the impact of crucial formulation
Gohl, Marcus, Wulff, Robert, Scholl, Peter, Günthner, Michael, Jung, Philipp Emanuel, Chapelot, Pierre
Technical Paper
Understanding how blending different ratios of renewable fuels with diesel impacts the toxicity of exhaust particulates to human health.2025-01-0207To be published on 06/16/2025
The urgent need to decarbonise transport has increased the utilisation of renewable fuels with current hydrocarbons. Heavy duty vehicle electrification solutions are yet to be realised and therefore the reliance on diesel engines may still be present for decades to come. Currently, the diesel supplied to fuel stations across the UK is a 7% blended biodiesel, whilst in South Korea a 5% blend is utilised. Biodiesel is produced from renewable sources for example; crops, waste residue and oils or biomass. Particulates from diesel combustion are known to be toxic, due to the presence of polyaromatic hydrocarbons (PAHs) however there is very limited understanding of blending oxygenated fuels on the toxicity of the particulates produced. PAHs are aromatic structures that can be metabolised into chemicals which can disrupt DNA replication and potentially influence cancer mechanisms if inhaled in high quantities. Soyabean methyl-ester (SME) was blended at lower ratios, e.g., 5%, 10%, 15% and
Hailwood, Emma, Hellier, Paul, Ladommatos, Nicos, Leonard, Martin
Technical Paper
Research on Combustion Characteristics of Flash-Boiling Spray in Cylinders Based on Machine Learning Methods2025-01-0205To be published on 06/16/2025
With the increasing number of vehicles in operation, exhaust emissions from engines have exerted negative impacts on ecological environments, prompting researchers to actively pursue cleaner and more efficient in-cylinder combustion strategies. Flash-boiling spray technology, capable of generating superior fuel atomization under relatively low injection pressures, has emerged as a promising approach for achieving performance breakthroughs in gasoline direct injection (GDI) engines. While current research primarily focuses on morphological characterization and mechanistic analysis of flashboiling spray, there remains insufficient understanding of flame development characteristics under flash boiling spray conditions within engine cylinders. This study systematically investigates the combustion characteristics of TPRF and PRF fuels under both subcooled and flash-boiling spray conditions through the integration of image processing and machine learning methodologies. Experimental
Zhang, Weixuan, Shahbaz, Muhammad, Cui, Mingli, Li, Xuesong, Xu, Min
Technical Paper
A Study on the Effects of Combustion Duration on Engine Behavior, Emissions, and Residual Gas in a Propane-Fueled Spark-Ignition Engine under Varying Loads2025-01-0202To be published on 06/16/2025
This study examines the effects of combustion duration on combustion behavior, pollutant formation, and residual gas fraction (RGF) in a propane-fueled spark-ignition engine across different load regimes. Experiments were conducted on a twin-cylinder research engine equipped with a dynamometer, varying the combustion duration between 40 and 80 degrees. Engine performance, emissions, and RGF were analyzed at engine loads of 25%, 50%, and 100%. The findings demonstrate distinct trends in combustion dynamics, emissions, and RGF as combustion duration and engine load change. At lower loads (25% and 50%), RGF fluctuations remain moderate, with peak values at specific combustion durations. In contrast, at 100% load, RGF shows significant deviations, indicating complex interactions between combustion and load. Additionally, variations in effective release energy (ERE), brake mean effective pressure (BMEP), and brake specific fuel consumption (BSFC) were observed, with longer combustion
Quach, Nhu Y
Technical Paper
Effect of ignition condition and fuel octane number on knock intensity in a small 2-stroke engine2025-01-0211To be published on 06/16/2025
The internal combustion engines are widely used on automotive transportation for its high energy storage system efficiency and the economic benefits. The 4-stroke engine has dominated all other forms to date, because the Otto cycle is much simpler to comprehend. However, the significant benefits such as, less pumping work and friction, lighter construction of 2-stroke engine, helped with applications which appreciate the simplicity and power density as well as meet the emission regulations. The disadvantages of the 2-stroke engine mainly caused by the lack of sufficient scavenging process, which limited its trapping efficiency. Also, the overlap of the intake and exhaust phases results in charge short-circuiting, more fuel consumption and high unburned hydrocarbon emissions. For the reason above, it is difficult for 2-stroke engines to realize stoichiometric combustion and unable to use three-way catalyst to control emissions. The residual exhaust gas in the cylinder makes the spark
Liu, Jinru, Iijima, Akira, Yamazaki, Yoshiaki, Yokota, Takumi, Kato, Hayato, Otaki, Yusuke
Technical Paper
Comparison of spark and turbulent jet ignition in a fully ammonia-fueled engine2025-01-0201To be published on 06/16/2025
Ammonia (NH₃) is an emerging carbon-free fuel with the potential to decarbonize the energy sector. However, its widespread adoption is hindered by challenges like low flame speed, high ignition energy, and elevated emissions of nitrogen oxides (NOx) and unburnt NH₃. These limitations necessitate innovative combustion strategies for efficient and stable engine operation. This study investigates the potential of turbulent jet ignition (TJI) to overcome these challenges through the implementation of a pre-chamber, a small auxiliary chamber equipped with a spark plug to create hot, reactive jets that propagate into the main chamber, promoting rapid combustion from distributed ignition sites. In this work, TJI operation is compared to conventional spark ignition (SI) in a Cummins ISB6.7 engine retrofitted for 100% ammonia operation. Experiments were conducted at 1200 and 1800 RPM across varying loads (25%, 50%, 75%, and 100%) with equivalence ratio and spark timing sweeps. Combustion
Dhotre, Akash, Voris, Alex, Okey, Nathan, Kane, Seamus, Northrop, William
Technical Paper
A Comprehensive Experimental Analysis of Ethanol 27% Fuel Blend in a Turbocharged Gasoline Direct Injection Engine2025-01-0245To be published on 06/16/2025
India is committed to achieving a 20% ethanol blend in petrol (E20) by 2025, as part of its national biofuels policy to reduce carbon emissions, enhance energy security, and support the agricultural economy. Building on E20's achievement in reducing GHG emissions, E27 fuel—which contains 27% ethanol in gasoline—is one of the means of advancing India's ethanol strategy and reducing dependency on fossil fuels. In line with the literature and the preliminary study, an experimental analysis utilizing fuel blends ranging from E10 to E40 was conducted. It was found that E27 provides the optimal balance of emissions reduction and performance without requiring engine modifications, complying with the government's aim to boost ethanol blending and cut carbon emissions by 2030. This study examines a turbocharged gasoline direct injection (TGDI) engine powered passenger car that was tested using E27 fuel for a mileage accumulation of 20,000 km under real-world driving conditions. This evaluation
D R, Vigneshwar, Bhakthavachalu, Vijayabaskar, Muralidharan, M.
Technical Paper
A Comparative Assessment of Port Fuel Injection and Direct Injection of Hydrogen in Internal Combustion Engines: Performance, Efficiency, and Emissions2025-01-0239To be published on 06/16/2025
With the transition toward low-carbon fuels-based transportation systems, hydrogen is becoming increasingly promising as a sustainable internal combustion engine (ICE) fuel. There are two pathways for introducing hydrogen: Port Fuel Injection (PFI) and Direct Injection (DI) in an engine, which greatly affects performance, efficiency, and emissions. In the Port Fuel Injection (PFI); hydrogen is introduced into the intake manifold and mixed with air before reaching the combustion chamber. This approach is preferred due to its affordability, ease of use, and compatibility with current engine configurations. Because of PFI's more uniform air-fuel mixture, combustion is smoother, and NOx emissions are reduced. On the other hand, it raises the possibility of pre-ignition, particularly when engine loads are high, and a decrease in volumetric efficiency due to a reduction in the volume of intake air as hydrogen replaces it. Direct injection gives exact control over the timing and volume of
Ahirwar, Sachin, Kumar, Naveen
Technical Paper
Statistical approach to develop Worst Case Cycle for BS6 RDE using On Road Data2025-01-0234To be published on 06/16/2025
The OEMs need to improve their Tail Pipe emission and confirm compliance to the norms for any on road driving condition. In the coming April 2022 BS6 RDE will be implemented, Failure to confirm leads to a huge penalty and damage to brand image. An optimized trade-off is required between fuel efficiency and tail pipe emissions. On-road cycles have random variation of conditions from terrain, traffic, temperature and driver behavior. This increases the risk of exceeding the compliance limits. The objective of the activity is to generate a Worst-case cycle that satisfies the IRDE boundary conditions and produces the maximum emission. To gain confidence before the actual implementation, two approaches were followed. In the first method, Random cycles were generated using a commercially available 1D simulation code. In the second method, Worst-Case Cycle was created from a MATLAB code was made to identify the worst engine out strips from over 1000 km data and was stitched with low
Krishnan, Karthikeyan N.
Technical Paper
An Experimental Study on Aqueous Ammonia and Diesel Dual-Fuel Combustion with Ignition Improving Additives in a Compression Ignition Engine2025-01-0231To be published on 06/16/2025
Ammonia is a potential vector of renewably produced hydrogen for combustion systems and decarbonisation of transport. However, anhydrous ammonia remains dangerous and difficult to handle due to its volatility and toxicity. Therefore, a water-based solution of ammonium hydroxide (NH4OH) was proposed to investigate the potential use as a fuel in a compression-ignition engine. Ammonium hydroxide, also referred to as aqueous ammonia, is liquid phase under atmospheric conditions; therefore, the storage of such a fuel does not require high pressure. Previous work has established that ammonium hydroxide solution could contribute to energy release during co-combustion with fossil diesel. However, the presence of water reduced combustion stability and limited the extent to which aqueous ammonia could displace diesel. In addition, the characteristics of pollutant emissions of burning such a fuel remained less understood. This study therefore explores the potential of ignition improving additives
Han, Yanlin, Hellier, Paul, Ladommatos, Nicos
Technical Paper
DoE-Based Numerical Optimization of Intake and Exhaust Port Geometry of a Small Opposed-Piston 2-Stroke (OP2S) Hydrogen Engine2024-32-0054To be published on 04/18/2025
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.
Technical Paper
A Power Split eCVT Hybrid for Sustainable Urban Mobility2024-32-0029To be published on 04/18/2025
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.
Technical Paper
Investigation on Degradation Process of PdRuIr/CZ “Pseudo-Rh” Catalysts Used for Motorcycles2024-32-0016To be published on 04/18/2025
Platinum (Pt), palladium (Pd), and rhodium (Rh) are used as active substances in exhaust gas purification catalysts for automobiles. Among these, Rh is an essential element because it efficiently promotes a NOx reduction reaction. On the other hand, the price of Rh has been rising in recent years. From the perspective of the supply risk of rare resources, there is an urgent need to develop technologies to replace or reduce the amount of Rh used in catalysts. We focused on the pseudo-rhodium alloy developed by the ACCEL program of the Japan Science and Technology Agency (JST), and then investigated the application of the pseudo-rhodium alloy on the catalysts of our motorcycles and also the degradation process. A nanosized PdRuIr alloy supported on a ceria-zirconia solid solution (PdRuIr/CZ) was prepared and assembled into a motorcycle for emissions measurement. The PdRuIr/CZ catalyst with an alloy loading of 4.0 g/L had initial properties comparable to the Rh supported on a CZ (Rh/CZ
Motegi, Takuya, Tatara, Shunya, Takamoto, Shunpei, Doi, Kosuke
Technical Paper
Development of a High-Frequency Measurement Apparatus for Evaluating Piston Friction in a Small Gasoline Engines2024-32-0100To be published on 04/18/2025
Efforts to enhance fuel efficiency in small gasoline engines, vital for reducing CO2 emissions, are concentrated on minimizing piston friction losses. Achieving this balance while addressing concerns such as piston seizure prevention and minimizing oil consumption presents challenges, particularly in small gasoline engines operating at higher speeds where the risk of piston seizure is significant. Hence, there is a critical need for accurate methods to measure piston friction. This study introduces the development of a measurement apparatus employing the floating liner method, initially devised by Takiguchi [1] and further adapted by Yamasaka for a mono-cylinder air-cooled gasoline engine [2, 3]. Yamasaka’s research successfully investigated the correlation between the apparatus’s natural frequency and the maximum engine speed measurable, achieving piston friction measurement up to 5000 rpm. Expanding on this achievement, this research aims to broaden the application of the floating
Honda, Riku, Ito, Akemi, Saika, Santa, Yamase, Ryouta, Hasegawa, Tatsuhiko, Sakioka, Takeru, Suda, Naoyuki, Ninomiya, Yoshinari
Technical Paper
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 System2024-32-0058To be published on 04/18/2025
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
Technical Paper
Basic Investigation of Thermodynamic Effects on a Hydrogen Two-Stroke Engine2024-32-0039To be published on 04/18/2025
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
Technical Paper
Research on the Combustion Characteristics of Port Injection Hydrogen Engines for Motorcycles2024-32-0094To be published on 04/18/2025
To prevent global warming, reducing CO2 emissions is the most important issue, and for this reason, efforts are needed to realize a carbon neutral society. Since hydrogen can be stored and transported, and does not emit carbon dioxide when burned, it has attracted particular attention as a fuel for internal combustion engines in recent years and has been studied in various industrial fields[1]. However, many of these studies have been conducted on commercial and passenger vehicle engines, and there has not yet been sufficient validation on small motorcycle engines. Therefore, in this study, a single cylinder gasoline engine for two-wheeled vehicles was converted into a hydrogen engine with port injection, and the abnormal combustion, which is a problem of hydrogen combustion, was verified. In this report, the parameters affecting the abnormal combustion are summarized based on the experimental results, and the reason why the parameters are a factor of the abnormal combustion generation
Suzuki, Haruaki, Inui, Taichi, Okado, Takanori, Tamura, Shohei, Kagawa, Yuta, Ninomiya, Yoshinari
Technical Paper
Development of Higher Clarity Injection Molded Windscreen for Motorcycles2024-32-0040To be published on 04/18/2025
The windscreen is one of the key elements to enhance passenger comfort of touring motorcycle. The clarity through the windscreen should not discomfort the rider. The discomfort we discuss here mainly refers to three factors: the “distortion,” the “blur,” and the “transparency.” Introduced in this paper is the technical measures to achieve sufficient clarity by the injection molding method. Firstly, with respect to the “distortion,” we determined the main cause was local unevenness of plate thickness. As the uneven thickness were related to the accuracy of the die, we clarified the tolerable zone and carried out higher precision machining of the die to satisfy the requirements. Regarding the “blur,” we analyzed the refractive power of the windscreen and found the main cause of blur is the microscopic roughness on the surface. As the microscopic roughness were attributable to the die surface, we clarified the tolerable zone and established the polishing conditions satisfactory for the
Yamada, Atsushi, Endo, Sakae
Technical Paper
Research on Basic Characteristics of a Two-Stroke Opposed Piston Engine2024-32-0112To be published on 04/18/2025
This study investigated the performance characteristics of a two-stroke opposed piston engine that is capable of constantly operating with high power output and high efficiency. An investigation was also made of the performance obtained by applying a pseudo uniflow condition as a measure against large hydrocarbon (HC) emissions owing to blow-by of unburned mixture, which is an issue of two-stroke engines. The test engine had a displacement of 127 cm3 and a bore and stroke of 48 x 70 mm. One-point and dual-point ignition systems were used, and regular gasoline was supplied as the test fuel using a carburetor-based fueling system. Experiments were conducted at engine speeds of 1500 and 3000 rpm at ignition timings of 45 deg. and 35 deg. before top dead center. The results showed that large quantities of HC emissions were emitted because stable combustion was not achieved. This revealed that a stronger uniflow condition must be applied as a countermeasure rather than a simple pseudo
Fukushima, Shumpei, Uehara, Ryota, Hayashi, Yoshiaki, Igarashi, Ryo, Tokita, Kazuho, Iijima, Akira
Technical Paper
Effects of Hydrogen Addition on Spark Knock Suppression under High Engine Speed and Boosted Conditions2024-32-0108To be published on 04/18/2025
The effect of hydrogen addition on spark knock suppression under high engine speed (4800 rpm) was investigated at the intake pressures of 96 kPa and 120 kPa. The experimental results showed that hydrogen addition has a slight effect on advancing the knock limit at 96 kPa, whereas a greater spark knock suppression effect can be achieved by increasing the intake pressure. To elucidate the influences and differences of hydrogen addition on the ignition process under low and high intake pressures, chemical kinetic analyses were performed using a two-zone combustion model. The calculation results showed that the reduction of heat release in the end gas resulting from the consumption of OH radicals by hydrogen can only be achieved at the initial stage of the ignition process. This leads to the smaller knock suppression effect at low intake pressures, where a remarkable heat release at this stage is absent. On the other hand, an increase in intake pressure results in a remarkable heat release
Goto, Jun, Ueno, Yoshito, Kobashi, Yoshimitsu, Shibata, Gen, Ogawa, Hideyuki, Kojima, Kentaro
Technical Paper
Coupled Analysis of First Principle Calculation and Chemical-Kinetics Simulation to Predict the Activity of Three Way Catalyst2024-32-0004To be published on 04/18/2025
This study proposes a technique to predict the catalytic activity of the CO-NO-O2 reaction using the first principle calculations without experiment. The proposed method consists of four steps. (1) Assuming the detailed chemical reactions based on the Langmuir-Hinshelwood mechanism. (2) Estimating the activation energy (Ea) for each detailed chemical reaction using first principle (e.g. Density Functional Theory: DFT) calculations. (3) Defining frequency factors (A) theoretically. (4) Inputting the estimated Ea and A values into simulation software for chemical-kinetics (e.g. exothermia suite) and running the simulation. The validity of the proposed method was evaluated by experiments. This study predicted the catalytic activities of Pt, Pd or Rh(111) surfaces. The predicted results qualitatively matched the experimental outcomes obtained from the Pt, Pd or Rh thin-film catalyst prepared by the “arc plasma method”.
Miura, Kazuya, Kusaba, Hiroki, Miyoshi, Tomoya, Yoshida, Hiroshi, Tsuchizaki, Hiroyuki, Machida, Masato
Technical Paper
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