Browse Topic: Combustion and combustion processes

Items (15,341)

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

2025-01-5026

04/03/2025

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

Zepf, Andreas, Härtl, Martin, Jaensch, Malte

Achieving Lagrangian-esque Fuel Mass Tracking in an Eulerian Frame of Reference CFD Diesel Engine Simulation

2025-01-8358

04/01/2025

Diesel combustion is a highly heterogeneous process in which the fuel must undergo several sub-processes after injection in order to release its heat through combustion. Prior to evaporation, computational fluid dynamic (CFD) simulations track the injected fuel mass using a Lagrangian frame of reference to determine the pathlines of the liquid fuel in the gaseous environment. However, after evaporation, when the fuel mass becomes part of the working fluid, it is no longer tracked in a Lagrangian reference frame as it undergoes its mixing and combustion processes. To gain deeper insights into the diesel combustion process, a methodology is proposed to track the evolution of fuel mass packets while in the gaseous state attaining a Lagrangian-esque description of the fuel’s evolution. This is achieved using the commercially available capabilities in Convergent Science’s CFD package, without requiring user-defined functions. The methodology is applied to a heavy-duty diesel engine and

Gohn, James, Kumar, Mohit, Gainey, Brian, Lawler, Benjamin

Data-driven Modeling and Control Framework for Multi-Fuel Compression-Ignition Engines

2025-01-8349

04/01/2025

Controlling the combustion phasing of a multi-fuel compression ignition engine in varying ambient conditions, such as low temperature and pressure, is a challenging problem. Traditionally, engine control is achieved by performing experiments on the engine and building calibration maps. As the number of operating conditions increase, this becomes an arduous task, and model-based controllers have been used to overcome this challenge. While high-fidelity models accurately describe the combustion characteristics of an engine, their complexity limits their direct use for controller development. In recent years, data-driven models have gained much attention due to the available computation power and ease of model development. The accuracy of the developed models, which, in turn, dictates the controller’s performance, depends on the dataset used for building them. Several actuators are required to achieve reliable combustion across different operating conditions, and obtaining extensive

Govind Raju, Sathya Aswath, Sun, Zongxuan, Kim, Kenneth, Kweon, Chol-Bum

Optical Investigation of DI Hydrogen Jet Development and Jet-Wall Interactions Under Engine-Like Conditions

2025-01-8456

04/01/2025

Direct injection (DI) hydrogen internal combustion engines are gaining attention as a promising technology for a sustainable energy transition, particularly in the transport sector. A key factor in improving the performance of these engines is understanding how hydrogen jets behave within the combustion chamber, especially their interactions with the chamber walls. These jet-wall interactions are critical since they have a major influence on fuel-air mixing which directly affects combustion efficiency and emissions. This study investigates the behavior of high-velocity hydrogen jets formed after exiting the injector. These jets propagate through surrounding air and interact with wall surfaces. When they impinge on wall surfaces, they undergo various processes such as radial spreading outward along the wall surface, mixing, and diffusion. These processes are influenced by factors including pressure ratio (PR) - the ratio between injection pressure and chamber pressure - and the geometry

Gong, Miaoxin, Lundgren, Marcus, Eismark, Jan, Andersson, Mats

Impacts of Injection Pressure on Split-Injection Energy-Assisted Compression-Ignition Combustion of Low Cetane Number SAFs with a Gaussian-Shaped Ribbed Piston Bowl Design

2025-01-8350

04/01/2025

The impact of injection pressure on a split-injection energy-assisted compression-ignition (EACI) combustion strategy was studied in an optically accessible engine with a custom ribbed piston bowl design. Three injection pressures (600, 800, and 1000 bar) were investigated for three split-injection dwells (1.5, 2.0, and 2.5 ms) with a fixed second injection timing of -5.0 CAD. The Gaussian-shaped ribbed piston bowl design was employed to position hot combustion gases from the first injection near the centrally located injector to enable rapid ignition and mixing-controlled combustion of the second injection. At 600-bar injection pressure, as injection dwell was shortened, relocation of hot combustion gases near the injector became increasingly more difficult due to less available time for relocation and due to the higher in-cylinder densities at the start-of-injection (SOI) for the first injection. Increased injection pressure (800 and 1000 bar) improved the relocation of the first

Amezcua, Eri, Stafford, Jacob, Kim, Kenneth, Kweon, Chol-Bum, Rothamer, David

Study on End Gas Auto-Ignition and Ion Current Formation Mechanism Based on One-Dimensional Flame Ionization Model

2025-01-8356

04/01/2025

In future spark-ignition internal combustion engines, characterized by high compression ratios, issues such as knocking and super-knocking have increasingly emerged as major factors limiting thermal efficiency improvements. Ion current detection technology, with its advantages of not altering engine structure, low cost, and maintenance-free operation, is considered as one of the most promising methods for in-cylinder combustion detection. However, the mechanism of ion current formation under end gas auto-ignition conditions remains unclear, and the matching law between the ion current signal and the combustion state can only be obtained by experimental and statistical methods so far, posing challenges for abnormal combustion diagnostics and control based on ion current detection technology. To analyze the signal characteristics of ion current under abnormal combustion from a more intrinsic perspective, this paper develops a one-dimensional flame ionization model using MATLAB. The model

Zhou, Yanxiong, Dong, Guangyu, Ni, Xiaoci, Xu, Jie, Li, Xian, Li, Liguang

Operating the Tour Split-Cycle Engine on Hydrogen/Methane Fuel Blends to Achieve High Efficiency and Reduction of Both GHG and NOx Emissions

2025-01-8422

04/01/2025

Decarbonized or low carbon fuels, such as hydrogen/methane blends, can be used in internal combustion engines to support ambitious greenhouse gas (GHG) emission reduction goals worldwide, including achieving carbon neutrality by 2045. However, as the volumetric concentration of H2 in these fuel blends surpasses 30%, the in-cylinder flame propagation and combustion rates increase significantly, causing an unacceptable increase in nitrogen oxides (NOx) emissions, which is known to have substantial negative effects on human health and the environment. This rise in engine-out NOx emissions is a major concern, limiting the use of H2 fuels as a means to reduce GHG emissions from both mobile and stationary power generation engines. In this study, an experimental investigation of the combustion performance and emissions characteristics of a 4th generation Tour split-cycle engine was undertaken while operating on 100% methane and various hydrogen/methane fuel blends (30%, 40%, and 50% by volume

Bhanage, Pratik, Cho, Kukwon, Anderson, Bradley, Kemmet, Ryan, Tour, Gilad, Atkinson, Chris, Tour, Hugo, Tour, Oded

Effects of Combustion Characteristic Parameters on Emission Performance in Ammonia-Hydrogen Internal Combustion Engine

2025-01-8425

04/01/2025

Under the background of the global dual carbon target, ammonia and hydrogen as the carbon-free fuel, have become a research hotspot for internal combustion engines. The existing researches mainly focus on the combustion characteristics influenced by equivalence ratio, hydrogen jet ignition and so on, while the relationship between combustion and emission characteristics should be also paid more attention. In this paper, the impact of combustion characteristic parameters on engine emissions is investigated by GT-power. The simulation model is based on a single cylinder engine with an active pre-chamber. Meanwhile, combustion characteristic parameters, in terms of CA50, combustion duration, CA10-CA50 and CA50-CA90 are set referred to the research of hydrogen jet ignition ammonia-hydrogen internal combustion engines. The results shown that there is compelling correlation between combustion parameters and specific emission profiles in ammonia-hydrogen internal combustion engines. Notably

Yuan, Yang, Shang, Quanbo, Deng, Jun, Li, Liguang, Yin, Xuemei, Lai, Huilong, Ma, Jiangli, Yu, Fei, Feng, Feng, Cui, Hao, Du, Junchen

Six Stroke Engine Optimization for Mid to High Loads Using Genetic Algorithm

2025-01-8438

04/01/2025

The development of new internal combustion (IC) engine technologies is essential as the automotive industry moves towards hybrid powertrains. Six-stroke (6S) gasoline compression ignition (GCI) engine is one such promising technology. It has the potential to improve performance and reduce emissions by introducing an additional power stroke (PS2) after the first power stroke (PS1). The aim of this study was to determine the optimal injection parameters for 6S GCI operation with one injection event in each power stroke. Parameters included the start of first (SOI1) and second injection (SOI2), and the fuel split ratio (SR) between PS1 and PS2. The study focused on mid (12, 15 bar) to high (18, 21 bar) engine loads, relevant for hybrid powertrains. Genetic algorithm technique was employed to optimize thermal efficiency while adhering to constraints on soot, NOx, maximum pressure rise rate (MPRR), and peak cylinder pressure (PCP). For 12 bar load, delaying the SOI1 timing to -4 CA ATDC led

Ullal, Ankith, Zhu, Shengrong, Ha, Kyoung Pyo, Purushothaman, Ashwin Karthik, Ra, Youngchul

Intebrake 3-D CFD Transient Simulation Studies for Predicting Flow Performance

2025-01-8362

04/01/2025

This paper presents transient, complex, moving mesh, 3-D CFD analysis of an intebrake lubrication oil circuit for predicting flow performance. Intebrake is a mechanism for improving braking performance during over speeding conditions. The mechanism briefly opens the exhaust valve at the end of a compression stroke with a small valve lift and releases the compressed gases, thereby helping in quick application of the brake. There is no fueling during the process and hence, no combustion induced pressure rise which helps in quick application of the brake. During the intebrake operation, opening of the exhaust valve is achieved by using a complex lube oil circuit inside the exhaust rocker lever. The intebrake lube oil circuit consists of various spring-operated valves with micro-sized clearances, high oil pressure generation up to ~ 250 bar, 3-D movement of the mechanism components, and it is a transient operation. The 3-D movement consists of simultaneous rotational and translational

Tawar, Ranjit Ramchandra, Pasunurthi, Shyam Sundar, Bedekar, Sanjeev, Ranganathan, Raj

Development of a Detailed Ignition Model with Energy Deposition and its Application to Full Engine Simulation

2025-01-8360

04/01/2025

A multi-dimensional model of the spark ignition process for SI engines was developed as a user-defined function (UDF) integrated into the commercial engine simulation software CONVERGE CFD. The model presented in this paper simulates energy deposition from the ignition circuit into the fuel-air mixture inside the cylinder. The model is based on interaction and collision between electrons in the plasma arc and the gas molecules inside the cylinder using parameters from the ignition circuit and gas inside the cylinder. Full engine simulations using CONVERGE CFD with the developed ignition model including the ignition circuit model, arc propagation model, and energy deposition model were performed to evaluate the validity and performance of the model and to compare with the ignition model provided by CONVERGE CFD. A low turbulent port fuel injected single-cylinder CFR engine was used for comparison. Continuous multi-cycle RANS simulations showed cycle-to-cycle variations. The range of the

Kim, Kyeongmin, Hall, Matthew, Joshi, Sachin, Matthews, Ron

Virtual Evaluation of Ceramic Glow Plug Design using Multiphysics Simulation Approach

2025-01-8367

04/01/2025

A glow plug is generally used to assist the starting of diesel engines in cold weather condition. Low ambient temperature makes the starting of diesel engine difficult because the engine block acts as a heat sink by absorbing the heat of compression. Hence, the air-fuel mixture at the combustion chamber is not capable of self-ignition based on air compression only. Diesel engines do not need any starting aid in general but in such scenarios, glow plug ensures reliable starting in all weather conditions. Glow plug is actually a heating device with high electrical resistance, which heats up rapidly when electrified. The high surface temperature of glow plug generates a heat flux and helps in igniting the fuel even when the engine is insufficiently hot for normal operation. Durability concerns have been observed in ceramic glow plugs during testing phases because of crack formation. Root cause analysis is performed in this study to understand the probable reasons behind cracking of the

Karmakar, Nilankan, Orban, Hatem

Evaluation of the Effect of Image Processing Methodology on Vapor Length and Spray Angle in a Constant Volume Combustion Chamber

2025-01-8465

04/01/2025

In direct injected engines the spray formation is important for both combustion performance and emission formation. Thus, being able to compare how the spray formation is affected by changes in nozzle design, injection pressure or fuel formulation is an important area of research for all engine sizes. This becomes especially important for the introduction of new sustainable fuels, or for fuel injection optimization to increase efficiencies and minimize the formation of emissions such as particles. High-speed imaging of the fuel spray using the schlieren technique is well established for this purpose, and the Engine Combustion Network (ECN) has developed multiple guidelines to ensure that a similar experimental approach is used in different laboratories around the world. For the initial image processing, the ECN provides a procedure based on an image-temporal-derivative approach. Many researchers however rely on intensity-based thresholding, preceded by contrast adjustment, background

Sileghem, Victor, Larsson, Tara, Dejaegere, Quinten, Verhelst, Sebastian

Numerical Study of the Hydrogen/Air Mixing in a High Performance 2 Stroke Opposed Piston Engine

2025-01-8365

04/01/2025

Hydrogen as a fuel for internal combustion engines is the most promising candidate for the achievement of the zero-emissions target fixed by the European institutions for sports car applications. The development of a high-specific-power hydrogen engine is not trivial considering the low volumetric energy density of hydrogen. Furthermore, the necessity to reduce the engine encumbrance in favour of on-board fuel storage makes alternative engine architectures, such as the two-stoke opposed-piston design, particularly attractive. A numerical study is conducted to evaluate the potential of such architecture. First, the overall engine is simulated in a 1D-CFD framework assuming a fully homogeneous hydrogen/air mixture. Then, the intake and exhaust port phasing are optimized, and a 3D CAD model of the cylinder is developed based on the defined parameters. 3D-CFD simulations of the scavenging process are performed and employed to tune the 1D model. Starting from a single point injection

Marini, Alessandro, Volza, Antonello, Baudone, Antonio, Mattarelli, Enrico, Fontanesi, Stefano, Di Sacco, Michele, Tonelli, Roberto, Breda, Sebastiano

Impact of Injector Geometry and Parcel Injection Location on Flash Boiling Spray Simulations of the ECN Spray G Injector

2025-01-8462

04/01/2025

For fuels sprays under flash boiling conditions, the near nozzle region experiences rapid changes in ambient conditions due to the flashing liquid. So, it is crucial to understand the influence of spray boundary conditions on parcel-based simulations for improved predictions of fuel spray behavior in engine applications. This study builds upon previous research investigating the impact of detailed injector tip geometry on parcel simulations of non-flash boiling conditions by investigating how flash boiling behaviors affect the near nozzle region and parcel initialization conditions. Four key parameters were varied individually from a baseline spray simulation model, which resulted in a total of five cases. The parameter variations were the presence of detailed injector tip geometry versus a simplified flat surface, parcel initialization at the nozzle exit versus at the counterbore exit, the use of experimental rate-of-injection versus one-way coupling with an internal nozzle Volume of

Kumar, Aman, Van Dam, Noah

Comprehensive Investigation of Combustion Characteristics, Emissions, and Tribological Properties of Synthetic Kerosene (S8) in a CVCC and CRDI Research Engine

2025-01-8443

04/01/2025

There is a need to reduce both the greenhouse gas emissions of internal combustion engines, and the reliance on traditional fossil fuels like Ultra Low Sulfur Diesel (ULSD). In this research, a synthetic paraffinic kerosene fuel, designated S8 and created from natural gas feedstocks using the Fischer-Tropsch process was investigated to determine its autoignition and combustion characteristics, emissions, and tribological properties. This fuel, S8, was found to have a Derived Cetane Number (DCN) of 62, which reflects a shorter Ignition Delay (ID), and Combustion Delay (CD) compared to ULSD, which has a DCN of 48. However, due to the chemical properties of S8, it lacks sufficient lubrication qualities in comparison to ULSD, so addition of 3% methyl oleate by mass was used to improve lubricity. The shorter ignition delay of S8, initially observed in a Constant Volume Combustion Chamber (CVCC) and confirmed in a fired Common Rail Direct Injection (CRDI) experimental engine. Investigations

Soloiu, Valentin, Willis, James, Norton, Coleman, Davis, Zachary, Graham, Tristan, Nobis, Austin

Assessment of a Heavy-Duty Diesel Engine Retrofitted to Dual-Fuel and Neat Methanol SI Operation

2025-01-8440

04/01/2025

This paper explores the potential of leveraging methanol's knock-resistant properties to facilitate both dual fuel (DF) and spark ignition (SI) operation in retrofitted heavy-duty (HD), high-speed marine engines. The study involves retrofitting an original 6-cylinder 7.15L CI diesel engine with port fuel injection (PFI) of methanol to enable DF operation. Later, the diesel injectors were replaced with six spark plugs allowing SI operation. Notably, efforts were made to minimize adaptations to the existing diesel engine, maintaining the compression ratio (CR) at 17.6:1 and retaining the same turbocharging pressure. This research aims to assess the feasibility of retrofitting conventional HD diesel engines (high CR, large bore) for dual-fuel and SI operation on methanol, with a focus on optimizing engine performance, while preserving key characteristics for HD applications, e.g. high torque and high power density. The high CR required spark retarding to prevent knock at higher loads in

Dejaegere, Quinten, Ballerini, Alberto, Demiddeleer, Sheldon, Vanderbeken, Thomas, Bracke, Kwinten, Gyselinck, Ben, D'Errico, Gianluca, Verhelst, Sebastian

A Study on Cetane on Demand Technology Part 2: Gasoline Reforming and Ignitability Evaluation

2025-01-8444

04/01/2025

The integration of low-octane gasoline with a compression ignition combustion system has been proposed as a strategy to reduce Well-to-Wheel CO2 emissions from automobiles in petroleum-based fuel. However low-octane gasoline is not widely available in the market currently. Onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. To reform commercial gasoline, a reformer with a spiral structure reactor and mechanical stirring air introduction was designed and prototyped based on the results of toluene reforming tests (A Study on Cetane on Demand Technology Part 1: Development of fuel reformer to improve fuel ignitability). Using N-hydroxyphthalimide (NHPI)-supported ZSM-5 as a catalyst, commercial gasoline was reformed. As a result, 25.5 liters of reformed gasoline was obtained. The hydroperoxide concentration in the entirety of our reformulated gasoline was determined to be

Matsuura, Katsuya, Hashimoto, Kohtaro, Yamada, Yoshikazu, Al-Taher, Maryam, Kalamaras, Christos, Voice, Alexander, Bhadra, Kaustav

Assessment of Knock Tendency in a Hydrogen-Fuelled High-Performance Internal Combustion Engine: A Chemistry-Based Numerical Study

2025-01-8429

04/01/2025

Hydrogen is a viable option to power high-performance internal combustion engines while reducing pollutant emissions thanks to its high lower heating value (LHV) and fast combustion rate. Furthermore, if compared to gasoline, hydrogen is characterized by a higher ignition delay time, which makes it more knock-resistant under the same thermodynamic conditions. In this paper, hydrogen potential as a fuel in a high-performance PFI naturally aspirated engine under stoichiometric conditions and high load regimes is investigated through zero and three-dimensional simulations. The analyses show that a stoichiometric hydrogen mixture reaches higher pressure and temperature values during compression than iso-octane at the same operating conditions, hence limiting the maximum engine compression ratio to avoid undesired ignitions throughout the combustion process. Additionally, hydrogen low density causes a reduction in terms of trapped energy inside the cylinder. Thus, despite its LHV is almost

Madia, Manuel, Vaccari, Marco, Dalseno, Luca, Cicalese, Giuseppe, Corrigan, Daire, Villa, Davide, Fontanesi, Stefano, Breda, Sebastiano

Effects of Post-Injection Strategy on the Performance of Diesel Catalyst-Heating Operation

2025-01-8414

04/01/2025

Minimizing the time needed to achieve light-off temperatures in diesel engine aftertreatment devices is key to mitigate pollutant emissions during the first minutes of operation. Catalyst heating operation typically includes one or multiple post-injections late during the expansion stroke aimed to increase the enthalpy of the exhaust gases. However, post-injection retardability is constrained by low combustion efficiency and the formation of CO and unburned hydrocarbons that cannot be oxidized by a still-inactive oxidation catalyst. In this study, the effects of post-injection strategy on the performance and emissions of a medium duty diesel engine have been investigated experimentally, focusing on the impacts on post-injection retardability. A five injection strategy (two pilot, one main, two post) was implemented in the engine, and the injection duration ratio between the two post-injections has been varied systematically while performing post-injection timing sweeps to identify the

Lopez Pintor, Dario, Lee, Sanguk, Cho, Seokwon, Busch, Stephen, Wu, Angela, Narayanan, Abhinandhan, Abboud, Rami

Effect of Geometrical Manipulation of the Pre-Chamber Design Parameters on the Combustion Performance of an Argon Power Cycle Engine

2025-01-8405

04/01/2025

Most of the power produced by manufacturing industry in the United States is via combined heat and power (CHP) systems, with most CHP installations using reciprocating internal combustion engines (RICE). RICE CHP systems offer several advantages, such as low installation and operational costs, high performance, load flexibility, and adaptability to various applications spanning from kilowatt to megawatt scales. Noble Thermodynamic Systems' (NTS) core technology, the Argon Power Cycle (APC), is a revolutionary, new power generation system that boosts the efficiency of RICE CHP generation systems while emitting zero greenhouse gasses or producing zero air pollutants, including nitrogen oxides (NOx). The APC uses the noble gas argon, a monatomic gas, which dramatically increases the specific heat ratio of the working fluid, resulting in a significantly higher ideal Otto cycle efficiency. The APC presents a promising solution to reach a carbon-neutral future for the energy needs of pivotal

Sharma, Eshan, Kim, Joohan, Strickland, Tyler, Scarcelli, Riccardo, Beardsell, Guillaume, Nilsen, Christopher, Sierra Aznar, Miguel

Research on the Combustion Characteristics of Gasoline Compression Ignition (GCI) Engine Based on Quasi-Homogeneous Mixture Charge Activity Control

2025-01-8409

04/01/2025

High-octane fuel presents significant potential for enhancing the efficient and clean combustion of small GCI engines. To achieve both efficient and stable combustion during low load scenarios, this study employs the combination of simulation and experimental methodologies. By coordinating the mixing rate and chemical reaction rate, as well as optimizing the equivalent ratio, temperature inhomogeneity and other parameters, introduces a control strategy termed ‘gasoline-air’ control coupling quasi-homogeneous mixture multi-pulse charge activity control. The research indicates that a quasi-homogeneous mixture can be formed through pilot injection of gasoline during the intake stroke, with low injection pressure can enhance charge activity and promoting clean combustion. The optimal injection timing is identified at approximately -315 CA ATDC, where appears peak value of indicated thermal efficiency. The multi-pulse charge activity control strategy can effectively control the combustion

Nie, JinLong, Yi, Yucheng

DME-to-Propane Mixture Effects on a Light Duty Compression Ignition Engine

2025-01-8415

04/01/2025

Fuels that can be produced in a sustainable manner are of high interest because they can provide an essential step toward net zero emissions vehicles. This study examines the combustion of two such fuels, Dimethyl Ether (DME) and propane, in a compression ignition, 4-cylinder, 2.2L engine running with mixtures of DME-to-Propane ranging of 100%-0%, 85%-15%, 75%-25%, and 65%-35% by weight. Testing was conducted at 2000rpm - 100Nm, an important representative point in the FTP certification cycle. For each fuel mixture, conditions tested include sweeps of boost, EGR and injection pressure. Tests are mainly conducted at a constant combustion timing with CA10 of -1 deg with respect to TDC, with an engine controller combustion feedback system based on in-cylinder sampling of pressure. Trends of NOx, HC, and CO are similar for the range of DME-to-propane, from 100%-0% to 75%-25%. Boost and injection pressures had the most notable impact on the heat release traces. Higher boost, from

De Ojeda, William, Wu, Simon (Haibao), Hall, Carrie, Ankobea-Ansah, King, Hassan, Hafiz Ahmad, Harrison, Christopher

Combustion and Emissions Improvement of Engine Idling Via Advanced Ignition Strategies

2025-01-8404

04/01/2025

During engine idling, the low engine speed, typically from 600 rpm to 800 rpm, together with the low throttle opening angle, makes it challenging for a proper fuel air mixing process. The uneven intake charge distribution and high portion of internal EGR because of the inefficient gas exchange process further make the air fuel ratio unstable, which is challenging for a robust ignition and combustion process. In this paper, the challenge of achieving proper combustion phasing while maintaining acceptable combustion stability is investigated, and a specially designed common-coil pack was utilized to improve engine idling performance by supplying prolonged ignition duration and elevated discharge current amplitude. The common-coil pack, which comprises three parallel connected ignition coils, was shared by all 4 cylinders of the engine. The ignition strategy shows the capability to advance the combustion phasing for higher IMEP output, while maintaining the combustion stability, and

Yu, Xiao, Chen, Guangyun, Qian, Jin, Leblanc, Simon, Wang, Linyan, Zheng, Ming

Fundamental Experimental Evaluation of Hydrogen Combustion with Low Injection Pressure Using the Focusing Compression Principle

2025-01-8423

04/01/2025

In our laboratory, the focusing compression principle has been proposed, which is based on pulsed multi-jets of gas colliding around the chamber center. This aims to reduce the cooling loss on the chamber wall and the exhaust loss and improve the thermal efficiency. Our past studies focused on gasoline combustion experiments using the engine with the principle and suggested that the engine had the potential to achieve high thermal efficiency and knock resistance. Considering these past results and the growing interest in carbon-free fuels for net zero, in this paper, fundamental experimental evaluations of hydrogen combustion were principally conducted using the same engine with the focusing compression principle. The air was injected toward the chamber center from seven intake nozzles, while hydrogen gas was supplied from one intake nozzle, respectively. Hydrogen was injected with a relatively low pressure of 50 kPaG. This means that an injector with high injection pressure was not

Yamada, Sota, Naitoh, Ken, Baba, Shotaro, Ukegawa, Hiraku, Nishizawa, Tomohiko, Yatabe, Atsuhiro

Optimizing Engine Component Design Using Advanced Techniques

2025-01-8647

04/01/2025

Designing engine components poses significant challenges due to the long simulation times required to model complex thermal and mechanical loads, such as high-pressure forces, vibration, and fatigue. Accurate simulations are critical for ensuring component reliability and durability, but they are computationally intensive, leading to prolonged development timelines. In the fast-paced automotive industry, where meeting tight deadlines is essential, lengthy simulation processes create bottlenecks that hinder achieving optimal design outcomes on time. To address this, we utilize a Modified Extensible Lattice Sequence (MELS) approach combined with Design of Experiments (DOE). MELS generates low-discrepancy, space-filling sequences that ensure uniform coverage across the design space, minimizing clusters and gaps in experimental designs. This tool streamlines the simulation process, enabling engineers to explore broader design parameters and optimize components efficiently. By forecasting

Dhangar, Vinaykumar, Goswami, Somshree

Modelling and Simulation of a Formula 1 Power Unit for 2026 and Predicting Formaldehyde Levels

2025-01-8004

04/01/2025

The transition to fully sustainable fuels, like ethanol, for Formula 1 power units in 2026 introduces challenges related to engine performance and emissions. The lower energy content of these fuels can have a negative impact on power output, while the increased levels of formaldehyde produced during combustion pose an environmental concern. This study aims to evaluate engine performance while meeting the FIA’s 2026 regulations using numerical simulations and to develop a method for estimating formaldehyde emissions produced during combustion. An F1 power unit model was developed in GT-Suite, incorporating all relevant regulations for 2026. The model was validated against literature data for combustion characteristics, such as laminar and turbulent flame speeds, and friction losses. Additionally, compliance with operational limits, such as energy flow restrictions, was confirmed. Suitable elementary and global reaction mechanisms for formation and destruction of formaldehyde were

Fuss, Nadine, Samuel, Stephen

Correlation Study of Low-Frequency Engine Order Noise Prediction at Compressor Inlet for a PHEV and Resonator Tuning

2025-01-8643

04/01/2025

Sound pollution has become one of the major environmental concerns for the global automotive industry. Air Induction System (AIS) plays an important role in engine performance and vehicle noise. An ideal design of AIS provides debris-free air for combustion and reduces the engine noise that is heard while snorkeling. This work aims to correlate low-frequency engine order noise prediction at the compressor inlet and snorkel inlet for a 2.0L I4 turbo engine of a Plug-in hybrid vehicle (PHEV) for better acoustic performance without compromising on engine performance. 1D simulation software GT-POWER, Simcenter 3D, and Hypermesh are used for this work. Transmission loss (TL) results with respect to the frequency of the air-box with ducts and intake manifold with charge air cooler are plotted from 0 to 1000 Hz. The air intake system TL results show a good correlation between 3D and 1D till 600 Hz. Compressor and snorkel noise simulation results, especially the firing order and its harmonic

Dixit, Manish

Performance and Emissions Analysis of a Hydrogen-Powered Heavy-Duty High Compression Ratio SI Engine Across Various Loads and Speed at Ultra-Lean Condition

2025-01-8428

04/01/2025

With the global shift towards sustainable and low-emission transportation, hydrogen-fueled engines stand out as a promising alternative to traditional fossil fuels, offering significant potential to reduce greenhouse gas emissions. This study provides a comprehensive evaluation of the performance and emissions characteristics of a hydrogen-powered heavy-duty compression ignition engine, which has been modified to operate as a Spark Ignition (SI) engine with a high compression ratio of 17:1. The evaluation was conducted across various speeds, loads, and spark timings under ultra-lean combustion conditions. The analysis utilized a modified 6-cylinder, 13-liter Volvo D13 diesel engine, configured to operate in single-cylinder mode with the addition of a spark plug for SI operation. The study examined key performance metrics, including brake thermal efficiency (BTE), power output, and specific fuel consumption, under the selected operating conditions. Emissions profiles for nitrogen oxides

Dyuisenakhmetov, Aibolat, Panithasan, Mebin Samuel, Cenker, Emre, AlRamadan, Abdullah, Im, Hong, Turner, James

Development of Ceramic Humidity Regulator (CHR) Using Honeycomb Type PTC Heater to Improve Electric Vehicle Driving Range in Winter

2025-01-8177

04/01/2025

With Rapid growth of Electric Vehicles (EVs) in the market challenges such as driving range, charging infrastructure, and reducing charging time needs to be addressed. Unlike traditional Internal combustion vehicles, EVs have limited heating sources and primarily uses electricity from the running battery, which reduces driving range. Additionally, during winter operation, it is necessary to prevent window fogging to ensure better visibility, which requires introducing cold outside air into the cabin. This significantly increases the energy consumption for heating and the driving range can be reduced to half of the normal range. This study introduces the Ceramic Humidity Regulator (CHR), a compact and energy-efficient device developed to address driving range improvement. The CHR uses a desiccant system to dehumidify the cabin, which can prevent window fogging without introducing cold outside air, thereby reducing heating energy consumption. A desiccant system typically consists of two

Hamada, Takafumi, Shinoda, Narimasa, Konno, Yoshiki, Ihara, Yukio, Ito, Masaki

Fuel Composition Effects on Combustion Characteristics of a Low-Temperature Gasoline Combustion Engine

2025-01-8410

04/01/2025

Low Temperature Gasoline Combustion (LTGC) in compression ignition engines is controlled by chemical kinetics and the autoignition reactivity of the fuel-air mixture, which are heavily influenced by the composition of the fuel. To investigate fuel-engine interactions, experiments were performed on a single-cylinder LTGC engine at various operating conditions with three premium-grade gasoline-like fuels with nominally the same octane rating but with high aromatic (HA), high cycloalkane (HCA) and high ethanol (E30 - 30%vol) contents, respectively. At fully-premixed naturally aspirated conditions, E30 showed the highest autoignition reactivity followed by HCA and HA. However, reactivity differences became less relevant when direct-injecting the fuel because of the vaporization cooling effect on the in-cylinder reactivity, which compensated for differences in fuel’s chemistry. Intake pressure sweeps demonstrated that the autoignition reactivity of E30 had the highest sensitivity to

Narayanan, Abhinandhan, MacDonald, James, Lee, Sanguk, Lopez Pintor, Dario

Experimental Study of Glow Plug Assisted Methanol Compression Ignition

2025-01-8412

04/01/2025

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

Control-Oriented Statistical Model of In-Cylinder Pressure, Combustion Phasing, and Torque for Compression-Ignition Engines Operating with Low Cetane Fuels

2025-01-8351

04/01/2025

Sustainable aviation fuels are becoming more widely available for current and future engine powered propulsion systems. However, the diversity of ignition behavior in these fuels poses a challenge to achieving robust, efficient operation. Specifically, low cetane fuels with poor ignitability exhibit highly variable torque production unless fuel is injected earlier during compression. The tradeoff is that earlier injection may cause dangerously high in-cylinder pressure rise rates. Novel models that can simulate these competing behaviors are needed so that appropriate strategies may be developed for controlling combustion at low cetane fueling conditions. This work builds upon a previously developed model that simulates asymmetric combustion phasing (CA50) distributions as a function of fuel cetane, fuel injection timing, and electrical power supplied to an in-cylinder thermal ignition assist device. An extension of the model is presented in which the phasing output is used to

Ahmed, Omar, Middleton, Robert, Stefanopoulou, Anna, Kim, Kenneth, Kweon, Chol-Bum

Effects of Intake and Exhaust Continuously Variable Valve Duration on Fuel Consumption and Emission Characteristics in Engine and Vehicle Tests

2025-01-8437

04/01/2025

An experimental study was conducted on a multi-cylinder engine equipped with both intake and exhaust continuously variable valve duration (CVVD). Due to CVVD and continuous variable valve timing (CVVT), valve closing and opening timings of both intake and exhaust sides became decoupled, so that four valve timings (opening and closing timings of intake as well as exhaust sides) can be optimized under each engine condition. Theses independent valve timings allowed reductions of fuel consumption as well as particle number (PN) and stoichiometry combustion under full-load condition without compromise of performance. In addition, to reduce raw gaseous emissions and shorten light-off time of catalyst under catalyst heating condition, various valve timings were tested in the engine test bench. As results, nitrogen oxides (NOx) – total hydrocarbon (THC) trade-off relation was relieved by optimal valve timings including negative valve overlap duration compared to the base engine. As the last

Jung, Jinyoung, Han, Sangyeon, Park, Sangjae, Kwon, Ki Young, Son, Yousang, Kim, Back-Sik, Kim, Youngnam

Experimental Study of Direct-Injection Compression-Ignition Hydrogen Combustion in an Opposed-Piston Two-Stroke (OP2S) Engine

2025-01-8430

04/01/2025

The future heavy duty powertrain market is expected to be more diverse, with a gradual shift towards cleaner and more sustainable alternative fuels. Among various options, the hydrogen Internal Combustion Engine (ICE) holds the promise of significantly reducing carbon emissions while leveraging existing ICE technology. However, it also faces substantial challenges related to engine performance, fuel storage and delivery, infrastructure development, economic feasibility, safety and market acceptance. This paper focuses on performance challenges of hydrogen engine, including knock and pre-ignition, as well as low thermal efficiencies, and introduces the Opposed-Piston Two-Stroke Hydrogen ICE (OP2S-H2ICE) as a potential solution. The study demonstrates that OP2S-H2ICE can operate using direct injection, compression-ignition (CI) combustion solely with hydrogen, under various low-load to partial load conditions. Specifically, as the load increases, the combustion transitions from partial

Huo, Ming, El-Hannouny, Essam, Longman, Douglas

Development of a 6.7L Direct Injection, Lean Burn H2 Spark Ignition Engine for Medium- and Heavy-Duty Commercial Vehicles

2025-01-8393

04/01/2025

This work is part of a production-intent program at Cummins to develop a 6.7L direct injection (DI), lean burn H2 spark ignition (SI) engine for medium- and heavy-duty commercial vehicles that are intended to be compliant with global VII criteria pollutants emissions standards. The engine features a low-pressure DI fuel injection system, a tumble-based combustion system with a pent-roof combustion chamber, two-stage boosting system without EGR, and dual overhead cams (DOHC) with cam phasers. The paper focuses primarily on the performance system architecture development encompassing combustion system, air-handling system, and valve strategy. Comprehensive 3D-CFD guided design analysis has been conducted to define the tumble ports, injection spray pattern, and injection strategy to optimize charge homogeneity and turbulence kinetic energy (TKE). In addition, the boosting system architecture and the valve strategy have been thoroughly evaluated through 1-D system-level engine cycle

Liu, Lei, Zhang, Yu, Qin, Xiao, Hui, He, Min, Xu, Leggott, Paul

Combustion and Emission Performance from the Use of Acid-Catalysed Butanol Alcoholysis Derived Advanced Biofuel Blends in a Compression Ignition Engine

2025-01-8445

04/01/2025

Low-carbon alternatives to diesel are needed to reduce the carbon intensity of the transport, agriculture, and off-grid power generation sectors, where compression ignition (CI) engines are commonly used. Acid-catalysed alcoholysis produces a potentially tailorable low-carbon advanced biofuel blend comprised of mixtures of an alkyl levulinate, a dialkyl ether, and the starting alcohol. In this study, model mixtures based on products expected from the use of n-butanol (butyl-based blends) as a starting alcohol, were blended with diesel and tested in a Yanmar L100V single-cylinder CI engine. Blends were formulated to meet the flash point, density, and kinematic viscosity limits of fuel standards for diesel, the 2022 version of BS 2869 (off-road). No changes to the engine set-up were made, hence testing the biofuel blends for their potential as “drop-in” fuels. Changes in engine performance and emissions were determined for a range of diesel/biofuel blends and compared to a pure diesel

Wiseman, Scott, Li, Hu, Tomlin, Alison S.

Development of Ultra-Fast AI-Driven Diesel Engine Model for Real-Time Optimization

2025-01-8397

04/01/2025

Combustion engines and hybrid systems remain important in sectors like light- and heavy-duty vehicles, where performance, range, or cost limitations play a major role. Optimizing diesel engine efficiency and reducing emissions is critical. However, classical physics-based 0D/1D models are computationally demanding and are hardly applicable for real-time purposes. In this study, a calibrated 1D diesel engine model is suggested for transformation into a neural network architecture to enable real-time optimization. The model divides the engine into intake, exhaust, and combustion sections, each modeled by different neural networks. One of the advantages of this modular and layered approach is the flexibility to change individual components without needing to retrain every single model. Long Short-Term Memory (LSTM) networks are used to capture transient phenomena, such as thermal inertias that arise in the combustion process and gas flow dynamics. The training data was generated by

Frey, Markus, Itzen, Dirk, Sautter, Johannes, Weller, Louis, Hagenbucher, Timo, Yang, Qirui, Grill, Michael, Kulzer, Andre Casal

Experimental Analysis of Piston Surface Temperature in a Heavy-Duty Compression Ignition Engine

2025-01-8383

04/01/2025

The heat transfer processes occurring in a compression ignition engine are complex, especially considering flame-wall interaction on the piston crown from impinging jets. To study the heat flux occurring on the piston in a heavy-duty diesel engine, a piston was instrumented with fifteen thermocouples and a wireless telemetry system. Eight of the thermocouples are high speed surface thermocouples placed primarily in regions with significant flame-wall interaction, providing crank-resolved surface temperature data. This work presents the first experimental datasets collected with this instrumented piston, describing in detail the thermocouple location selection process as well as data processing and uncertainty quantification for the high-speed surface thermocouples with a particular emphasis on cyclic variability and sensor-to-sensor variability. With this methodology established, data from this piston can be used for modeling and simulation studies as well as for studying the impact of

Gainey, Brian, Datar, Aditya, Ravikumar, Avinash, Bhatt, Ankur, Vedpathak, Kunal, Kumar, Mohit, Gingrich, Eric, Tess, Michael, Korivi, Vamshi, Lawler, Benjamin

Effects of Ambient and Injection Conditions on a High-Pressure Hydrogen Jet for Direct Injection in ICE

2025-01-8466

04/01/2025

The transport sector is responsible for about one third of the global CO2 emissions. To align to the net zero emission scenario, the transportation sector needs the implementation of policies aimed to reduce as much as possible the highly emitting transport options and, at the same time, the use of new technologies to reduce the environmental impact of transport methods whose emissions cannot be entirely eliminated. An exploitable solution for the internal combustion engine (ICE), even in the nearest future, would be to use hydrogen as a fuel in these engines. This is supported by the fact that H2-ICE is the only ICE technology currently capable of meeting the standards imposed by the European Union for 2035. Due to the possibility of different injection strategies as well as the variation of in-cylinder back pressure, the comprehensive knowledge of hydrogen injection jet behavior and characteristics is fundamental for improving the combustion process in direct injection H2-ICE. In

Montanaro, Alessandro, Mancaruso, Ezio, Meccariello, Giovanni, Allocca, Luigi

A Conjugate Heat Transfer Numerical Framework Applied to Energy-Assisted Ignition of Jet Fuel in a Rapid Compression Machine

2025-01-8352

04/01/2025

Airborne compression ignition engines operating with aviation fuels are a promising option for reducing fuel consumption and increasing the range of hybrid-electric aircraft. However, the consistent ignition of Jet fuels at high-altitude conditions can be challenging. A potential solution to this problem is to ignite the fuel sprays by means of a glow-plug-based ignition assistant (IA) device. The interaction between the IA and the spray, and the subsequent combustion event result in thermal cycles that can significantly affect the IA’s durability. Therefore, designing an efficient and durable IA requires detailed understanding of the influence that the IA temperature and insertion depth have on the complex physics of fuel-air mixture ignition and flame propagation. The objective of this study is to design a conjugate heat transfer (CHT) modeling framework that can numerically replicate F-24 Jet fuel spray ignition using a glow-plug-based IA device in a rapid compression machine (RCM

Oruganti, Surya Kaundinya, Lien, Hao-Pin, Torelli, Roberto, Motily, Austen, Lee, Tonghun, Kim, Kenneth, Mayhew, Eric, Kweon, Chol-Bum

A Study on Reconstructing in-Cylinder Combustion Images Based on Local Images

2025-01-8381

04/01/2025

The current leading experimental platform for engine visualization research is the optical engine, which features transparent window components classified into two types: partially visible windows and fully visible windows. Due to structural limitations, fully visible windows cannot be employed under certain complex or extreme operating conditions, leading to the acquisition of only local in-cylinder combustion images and resulting in information loss. This study introduces a method for reconstructing in-cylinder combustion images from local images using deep learning techniques. The experiments were conducted using an optical engine specifically designed for spark-ignition combustion modes, capturing in-cylinder flame images under various conditions with high-speed cameras. The primary focus was on reconstructing the flame edge, with in-cylinder combustion images categorized into three types: images where the flame edge is fully within the partially visible window, partly within the

Wang, Mianheng, Zhang, Yixiao, Du, Haoyu, Xiao, Ma, Mao, Jianshu, Fang, Yuwen

Experimental Investigation between Pre-Ignition, Knocking, Vibration and Performance in an Internal Combustion Engine

2025-01-8380

04/01/2025

Otto cycle internal combustion engines have undergone technological developments that can be fueled by various types of fuels in different mixture proportions. To achieve this, a detailed study of the main factors that influence the engine combustion process is necessary. The objective of this study is to evaluate the effects of varying the ignition advance on the performance parameters and vibration level of the engine operated with regular gasoline, podium gasoline, ethanol and a mixture of ethanol with regular gasoline. The experimental tests consisted of operating an Otto cycle engine on a bench dynamometer under full load conditions, varying rotation and ignition advance by 5, 10 and 20% in relation to the original ignition advance and correlating the levels of pre-ignition, knock, engine vibration levels with engine performance parameters. The results showed that the engine vibration level was influenced by the type of fuel used, engine performance parameters and the presence of

Santana, Claudio

Development of the Tour Split-Cycle Internal Combustion Engine

2025-01-8394

04/01/2025

The Tour engine is a novel split-cycle internal combustion engine (ICE) that divides the four-stroke Otto cycle of a conventional ICE between two separate cylinders, an intake and compression cylinder and a second expansion and exhaust cylinder, interconnected by an innovative charge transfer mechanism. The engine working fluid, air and fuel, is inducted into the engine and compressed by a dedicated compression cylinder, transferred with minimal pressure loss via an input port to a specifically designed combined spool shuttle transfer mechanism and combustion chamber. It is then ignited and then transferred from the combustion chamber via an exit port to a separate expansion cylinder where it is expanded and exhausted from the engine. The primary advantage of the Tour engine is that it provides the engineering freedom to independently design, control and optimize the compression, combustion, and expansion processes within a slider-crank piston engine. By decoupling the compression

Tour, Oded, Cho, Kukwon, Hofman, Yehoram, Anderson, Bradley, Kemmet, Ryan, Morris, Daniel, Wahl, Michael, Bhanage, Pratik, Sivan, Ehud, Tour, Gilad, Atkinson, Chris, Tour, Hugo

Comparison of Gasoline Particulate Indices Using U.S. Market Gasoline Samples

2025-01-8449

04/01/2025

Simulated distillation (SimDis) uses wide bore capillary gas chromatography (GC) to provide a detailed volatility profile of blended gasoline. The boiling point distribution from SimDis analysis is correlated to the hydrocarbon contents of spark ignition fuels and provide the resolution necessary to characterize the compositions of the fuel. Recent publications on simulated distillation applied to spark ignition fuel reveal the merits of indexing a gasoline fuel so that it can be correlated to the tendency of particulate emissions from vehicles. With this in mind, SimDis can be a useful and quick tool in assessing the PM-formation potential of market gasolines. Heavy aromatic compounds are compounds identified as having at least 10 Carbons and 1 aromatic ring. These compounds that are present in spark ignition fuels are major contributors to vehicle particulate emissions. These compounds can be found in the higher boiling portion (T70+) of the distillation profiles. As demonstrated in

Goralski, Sarah, Geng, Pat, Dozier, Jon, Butler, Aron

A Computational Investigation of Hydrogen Pre-Chamber and Spark-Ignition Combustion Engines at Different Load Conditions

2025-01-8406

04/01/2025

Pre-chamber (PC) technology has demonstrated its capability to achieve clean and stable combustion in internal combustion engines (ICEs) under lean conditions. This study evaluates the effectiveness of PC in direct injection (DI) hydrogen (H2)-ICEs compared to conventional spark ignition (SI) operation using high-fidelity computational fluid dynamics simulations across a range of load conditions. Various loads were attained by systematically adjusting intake pressure and injected H2 mass. The primary hypothesis posits that highly turbulent PC jets facilitate rapid mixing and combustion of ultra-lean mixtures. The comparative analysis revealed that DI fueling in both PC and SI modes did not achieve perfectly homogeneous mixtures, particularly under high load conditions, although PC slightly enhanced mixture uniformity. Combustion behavior exhibited a non-monotonic trend, with SI outperforming PC at low and high loads, while PC demonstrated superior performance at medium loads despite

Menaca, Rafael, Liu, Xinlei, Mohan, Balaji, Cenker, Emre, AlRamadan, Abdullah, Im, Hong

The Effect of Nitric Oxide (NO) on the Reactivity of Ethanol and Gasoline: An Experimental Study

2025-01-8413

04/01/2025

Achieving stable HCCI combustion requires specific in-cylinder boundary conditions. Trace residual species, such as nitric oxide (NO), can have an impact on the reactivity, and thus the combustion stability, of different fuels in HCCI. This study investigates the effects of nitric oxide (NO) on the reactivity and combustion stability of ethanol and gasoline in a single-cylinder HCCI engine. The promoting and inhibiting impact of NO on iso-octane’s ignition delay time are available in the literature; nevertheless, as a baseline study, these effects on the autoignition of gasoline were documented in this work. For ethanol, the NOx concentration seeded in the intake air varied from 0-1000 ppm while maintaining a constant combustion phasing (CA50 at 7.5 CAD) and a global equivalence ratio of 0.34. Ethanol exhibited a linear reduction in intake temperature, decreasing by 47 K with 927 ppm NO. For gasoline, a 225-ppm increase in NO reduced the intake temperature required for HCCI by 40 K

Bhatt, Ankur, Gandolfo, John, Vedpathak, Kunal, Lawler, Benjamin, Gainey, Brian

Combustion Characterization and Heat Release Rate Modeling of a Heavy-Duty Hydrogen-Diesel Dual-Fuel Engine

2025-01-8418

04/01/2025

Introducing hydrogen (H2) into the intake air of diesel engines provides a near-term approach to reducing tailpipe CO2 emissions from heavy-duty commercial vehicles. The premixed hydrogen results in a complex H2-Diesel dual fuel (H2DF) combustion process, where H2 can both participate in the non-premixed diesel combustion and result in a propagating H2/air combustion. These interactions influence engine combustion characteristics, including in-cylinder pressure and heat release rate (HRR), as well as emissions. The nature and extent of the impact depends on the amount of H2 introduced as a function of the total fuel energy (H2 energy share ratio - HES), the trapped air mass, and engine operating conditions. To optimize the HES ratio under different conditions, it is crucial to understand how H2DF combustion differs from diesel combustion and how this limits engine operation and impacts emissions. To investigate these effects, a heavy-duty class 8 truck fitted with an H2DF system

Farzam, Reza, Guan, Mang, Gmoser, Raine, Steiche, Patrick, Kirchen, Patrick, McTaggart-Cowan, Gordon

Characterization of Spark Ignition Energy Transfer at Different Phases Using Pressure-Rise Calorimetry

2025-01-8402

04/01/2025

The paper presents novel studies on the electrical-to-thermal energy deposition to gas at different phases of a spark. The experiments utilized a 10.9 milliliter custom-built spark calorimeter. The energy transfer efficiencies across spark phases—breakdown+arc, and glow are quantified, emphasizing their importances in ensuring robust ignition. An AC capacitive ignition system was considered in the experiments. The spark plugs used in the experiments were of dual-nickel standard J-gap design of a fixed electrode gap. Test results show the breakdown+arc phases are highly efficient in converting electrical to thermal energy, crucial for ignition. The glow phase, offering control flexibility, is found to be less effective in energy transfer from spark to gas. In addition, a maximum threshold for both glow current and duration is found. Exceeding the threshold reduces the net energy deposition to the gas, indicating an increase in thermal energy losses, primarily to the spark plug

Saha, Anupam, Tunestal, Per, Aengeby, Jakob, Andersson, Oivind

Effects of Lubricating Oil Consumption and Operation Duration on CO ₂ Accumulation and Efficiency in an Argon Power Cycle Hydrogen-Fueled Engine

2025-01-8436

04/01/2025

The trend of internal combustion engines is reducing or eliminating carbon emissions and improve the overall efficiency. The Argon Power Cycle hydrogen-fueled engine can specifically improve the thermal efficiency by employing argon as the working substance. At the same time, due to the utilization of hydrogen and oxygen, the combustion of the fuel in Argon Power Cycle hydrogen-fueled engines produces zero carbon emissions or NOx emissions. However, during engine operation, lubricating oil consumption can still generate CO2 and becomes the only source for carbon emissions. Furthermore, the accumulation of CO2 under closed cycle will impede the condensation recovery of argon and reduce the efficiency and power. In this study, a closed cycle model of Argon Power Cycle hydrogen-fueled engine was constructed, in which argon is recycled by condensation instead of being charged like air in an open cycle model. Effects of lubricating oil consumption and operation duration on CO2 accumulation

Wang, Chenxu, Li, Mo, SU, Xiang, Deng, Jun, Tian, Tian, Li, Liguang

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