Browse Topic: Combustion and combustion processes

Items (15,366)

Advanced Engine Cooling System for a Gas-Engine Vehicle, Part III: State Feedback Control System Design

2025-01-8161To be published on 04/01/2025

This paper presents an advanced control system design for an engine cooling system in an internal combustion engine (ICE) vehicle. Building upon our previous work, we have derived models for crucial temperatures within the engine, including combustion wall temperature, coolant-out temperature, block temperature, as well as temperatures in external components such as heat exchangers and radiator. To accurately predict these temperatures in a rapid manner, we have utilized a lumped parameter concept with a mean-value approach. This approach allows for precise temperature estimation while maintaining computational efficiency. Given the complexity of the cooling system, we have proposed a linear time-varying (LTV) model predictive control (MPC) system to regulate the temperatures. This control system linearizes the model at each time step and applies linear MPC over the control and prediction horizons. By doing so, we effectively control the highly nonlinear and time-delayed system

Chang, Insu, Sun, Min, Edwards, David

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

2025-01-8177To be published on 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 power 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 power consumption. A desiccant system typically consists of two

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

The numerical study of methane flame characteristics in the ammonia/air environment at sub-atmospheric pressure

2025-01-8450To be published on 04/01/2025

The low emission of carbon and minimum level of soot formation in combustion engines and turbines strategy is adopted by many countries to counteract global warming and climate change. The combustion and emission characteristics of methane coflow flame were studied at low pressure and air polluted by ammonia conditions. The results showed that a significant decline in carbon formation was observed when ammonia was boosted, 5-10%. The impact of sub-atmospheric pressure, 90-70 KPa, on COx development was higher than that of NH3 addition, 0-5%, thanks to the lower formation of hydroxymethylium, formaldehyde, and aldehyde radical. The sub-atmospheric pressure had more impact on the reduction of nitric oxide than that of nitrous oxide, and ammonia impact was greater on the increment of nitric oxide than that of nitrous oxide. The maximum reduction and increment in the profile of nitric oxide were observed ~ 42.1% at 5% NH3 and 182% at 80 KPa. The acetylene species was more affected by sub

HINA, ANAM, Akram, M Zuhaib

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

2025-01-8430To be published on 04/01/2025

The future heavy duty powertrain market is expected to be more diverse, with shifts gradually towards cleaner and more sustainable alternatives. Among various options, the hydrogen ICE holds the promise of significantly reducing 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 by introducing 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 conditions. Specifically, as the load increases, the combustion transitions from partial-premixed controlled CI combustion towards mixing

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

A Comparison of Stochiometric and Lean Burn Ammonia-Hydrogen Co-fuelling in a Modern Spark ignition Engine

2025-01-8432To be published on 04/01/2025

Ammonia (NH3) is emerging as a promising fuel for longer range decarbonised heavy transport, predominantly due to relative favourable characteristics as an effective hydrogen carrier. This is despite generally unfavourable combustion and toxicity attributes, restricting end use to applications where robust health and safety protocols can always be assured. In the currently reported work a spark ignited thermodynamic single cylinder research engine was equipped with separate gaseous ammonia and hydrogen port injection fuelling, with the aim of understanding the impact of varied co-fuelling upon combustion, fuel economy and engine-out emissions (and the arising implications upon future emissions after-treatment). Under stoichiometric conditions, the engine could be operated in a stable manner on pure NH3 at low-to-medium speeds and medium-to-high engine loads, with up to ~20% hydrogen (by energy) required at the lowest engine loads. Engine-out NH3 emissions remained relatively high

Ambalakatte, Ajith, Geng, Sikai, Murugan, Reese, Varaei, Amirata, Cairns, Alasdair, Harrington, Anthony, Hall, Jonathan, Bassett, Michael

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

2025-01-8449To be published on 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 that are present in spark ignition fuels are major contributors to vehicle particulate emissions. These compounds are present in the higher boiling portion (T70+) of the distillation profiles. As demonstrated in recent studies, the particulate indices of gasoline samples are indicative of the relative

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

Ammonia-Hydrogen Combustion in a Heavy-Duty Diesel Engine Converted to Spark Ignition Operation

2025-01-8448To be published on 04/01/2025

Ammonia is a carbon-free fuel alternative for the internal combustion engine decarbonization. However, its toxicity and less advantageous combustion characteristics including higher nitrogen-based engine-out emissions have delayed its use in power generation applications. Therefore, the use of a secondary and also carbon-free fuel such as hydrogen was proposed in the literature as a solution to promote and improve ammonia combustion while minimizing any modifications in engine parameters and control strategy that may be required when compared to using conventional hydrocarbon-based fuels. In addition, the higher resistance to autoignition of ammonia can allow operation at higher compression ratios in spark ignition applications, therefore increasing the thermal efficiency. The study presented here used a single-cylinder heavy-duty research engine converted to spark ignition operation to investigate medium load engine operation with ammonia-hydrogen blends in which hydrogen represented

Alvarez, Luis, Saenz Prado, Stefany, Trujillo Grisales, Juan, Dumitrescu, Cosmin

Fuel composition effects on combustion characteristics of a Low-Temperature Gasoline Combustion engine

2025-01-8410To be published on 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 in 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

Optimizing Engine Component Design Using Advanced Techniques

2025-01-8647To be published on 04/01/2025

Designing engine components presents significant challenges due to the extensive simulation times required to model the complex thermal and mechanical loads they encounter. These include extreme heat generated during combustion, thermal cycling from repeated heating and cooling, and uneven temperature distribution across components, which result in thermal gradients. Mechanical stresses such as high-pressure forces, vibration, and fatigue further complicate the design process. Accurate simulation of these conditions is crucial for ensuring component reliability and durability, but it is both time-consuming and computationally intensive. The iterative nature of the design process, which involves multiple cycles of refinement and optimization, exacerbates these challenges, leading to prolonged development timelines. In the fast-paced automotive industry, where meeting tight deadlines is critical, the lengthy simulation times create significant bottlenecks, making it difficult to achieve

Dhangar, Vinaykumar, Goswami, Somshree

Effects of Injection Timing and Pressure on Combustion Performance and Emissions in Hydrogen Direct Injection Engine

2025-01-8421To be published on 04/01/2025

As the demand for cleaner and more efficient propulsion systems increases, hydrogen internal combustion engines have emerged as a promising solution due to their high thermal efficiency and zero-carbon emissions potential. Achieving ultra-lean combustion conditions (lambda > 2.8) in hydrogen engines significantly improves thermal efficiency while maintaining combustion stability and reducing knock intensity. However, hydrogen injection timing and pressure are crucial factors influencing the combustion and emission characteristics of hydrogen engines. This study investigates the effects of hydrogen injection timing and pressure on the combustion performance and emission characteristics of a direct injection hydrogen engine under different load conditions. Experimental tests were conducted on a multi-cylinder engine equipped with a hydrogen direct injection system, focusing on part-load operation to explore the interplay between injection parameters and engine performance. Results show

Du, Jiakun, Wu, Guangquan, Chen, Hong, Sun, Fanjia, xie, Fangxi, Li, Yuhuai, Sun, Yao, Qi, Hongzhong, Li, Yong

Energy Conversion Efficacy of Neat Dimethyl Ether Combustion with Heat Release Characterization and Emission Analysis

2025-01-8417To be published on 04/01/2025

Dimethyl ether (DME) is widely regarded as a suitable energy source for compression ignition power systems because of its high reactivity. It has been widely reported that DME possesses a significantly low propensity to form soot, hindering the innate NOx-soot trade-off encountered with diesel fuel operation. Beyond the fuel-borne oxygen content of DME, its unique physical properties present a contrasting combustion behavior which may be advantageous to direct injection systems, especially concerning the mixing-controlled combustion mode. This work aims to detail the energy conversion efficacy of DME through heat release characterization and exhaust emission speciation. The tests were controlled within a single-cylinder research engine with an off-board high-pressure injection system to handle liquified DME up to 1000bar. To mitigate interference in fuel additives over the combustion behavior, the high-pressure fuel system specifically managed neat DME. The in-cylinder pressure was the

Leblanc, Simon, Cong, Binghao, Leach, Jace, Yu, Xiao, Reader, Graham, Zheng, Ming

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

2025-01-8393To be published on 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 complaint with global VII criteria pollutants emissions standards. The engine is featured with 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 primary focus of this paper is 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

Liu, Lei

Spray Characterization in a Constant Volume Chamber of Aluminum Oxide Nanoparticles-Diesel Blends

2025-01-8455To be published on 04/01/2025

Aluminum oxide (Al₂O₃) nanoparticle are considered a promising fuel additive to enhance combustion efficiency, reduce emissions, and improve fuel economy. This study investigates the spray characteristics of diesel fuel blended with aluminum oxide nanoparticles in a constant volume chamber. The blends were prepared by dispersing Al₂O₃ nanoparticles in diesel at varying concentrations (25, 50, and 100 mg of aluminum oxide nanoparticles into 1 L of pure diesel, respectively) using a magnetic stirrer and ultrasonication to ensure stable suspensions. Spray characterization was conducted in a high-pressure and high-temperature constant volume chamber, simulating actual engine conditions. The ambient temperatures for this experiment were set from 800 to 1200 K, and the oxygen concentrations were set from 21% to 13%. The study focused on key spray parameters such as spray penetration length, spray angle, and spray area, analyzed using high-speed imaging and laser diffraction techniques

Ji, Huangchang, Zhao, Zhiyu

Knock Assessment in Wankel Rotary Engine Adopting Low Octane Rating Fuels

2025-01-8452To be published on 04/01/2025

Series hybrid vehicles, equipped with internal combustion range extenders, are a promising solution for carbon-free transportation. In this application, zero net carbon emissions can be achieved only using renewable fuels. Fischer-Tropsch-derived e-gasolines allow for high energy density and safe fuels. However, Fischer-Tropsch fuels must undergo several processing stages to reach current engine-grade octane ratings, negatively affecting the synthesis's profitability and energy efficiency. Gasoline engine technologies capable of operating with low-octane fuels could allow the adoption of unprocessed Fischer-Tropsch gasoline. The rotary Wankel engine design suits range extenders thanks to its high power-to-size ratio. In this study, the knocking tendency of homogenous charge spark-ignition rotary Wankel engines is numerically assessed through Chemkin-Pro spark-ignition engine zonal model for knock assessment. Rotary Wankel engines are modeled by providing the corresponding time

Brunialti, Sirio, Vorraro, Giovanni, Turner, James, Sarathy, Mani

Study of the Effects on Plain Bearings in Simulated Corrosion Tests Using Carbon neutral Fuels

2025-01-8470To be published on 04/01/2025

Many countries around the world are currently working toward carbon neutrality, which would reduce greenhouse gas emissions to net zero by 2050. As part of our efforts to achieve carbon neutrality, we have developed low friction bearings that contribute to reduced fuel consumption, and high load capacity bearings for increased engine output and longer service life. Meanwhile, Countries around the world are also considering engines that use carbon-neutral (CN) fuels, such as hydrogen and e-fuel, as part of their efforts to achieve carbon neutrality. It was reported that CN fuels differ significantly from gasoline and diesel in the chemical composition of gases produced after combustion. In particular, hydrogen-fueled internal combustion engines generate more water during combustion than gasoline engines, and nitrogen oxides emissions (NOx) have also been observed under some combustion conditions. Dissolution of these substances in engine oil is expected to create a corrosive environment

Kondo, Makoto, Kawaura, Hiroki, Shiroya, Tomoyasu, Watanabe, Airi

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

2025-01-8437To be published on 04/01/2025

An experimental study was conducted on a multi-cylinder engine equipped with both intake and exhaust continuously variable valve duration (CVVD). Thanks to CVVD, valve closing and opening timings are decoupled, therefore, four valve timings (opening and closing timings of intake as well as exhaust sides) can be optimized under entire engine conditions in terms of minimum brake specific fuel consumption and particle number (PN) emission. Consequently, λ = 1 operation under all engine conditions was achieved without compromise of both fuel economy and performance. Furthermore, to reduce raw emissions and shorten light-off time of catalyst under catalyst heating condition, valve and injection strategies were tested. As a result, it was found that certain level of negative valve overlap duration was beneficial to secure combustion stability, and early exhaust valve opening timing increased exhaust gas temperature for catalyst heating. Therefore, both shorted light-off time and raw engine

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

High-Speed Optical Diagnostics of Misfire Limits in a Spark-Ignited Heavy-Duty Hydrogen Engine

2025-01-8401To be published on 04/01/2025

This study investigates the ignitability of hydrogen in an optical heavy-duty SI engine. While the ignition energy of hydrogen is exceptionally low, the high load and lean mixtures used in heavy-duty hydrogen engines lead to a high gas density, resulting in a much higher breakthrough voltage than in light-duty SI engines. Spark plug wear is a real concern, so there is a need to minimize the spark energy while maintaining combustion stability. The first part of this study was performed on an optical engine fitted with a metal piston. In this configuration, we mapped the combustion stability and frequency of misfires with two different ignition systems: a common inductive system and an actively controlled capacitive system. The equivalence ratio and dwell time were varied for the inductive system while the capacitive system instead varied spark duration and spark current in addition to equivalence ratio. A key finding was that leaner mixtures require longer dwell time or longer spark

Hallstadius, Peter, Saha, Anupam, Sridhara, Aravind, Andersson, Öivind

Exploring the effects of varying pre-chamber geometry in a heavy-duty natural gas optically accessible engine under dilution conditions

2025-01-8407To be published on 04/01/2025

Pre-chamber combustion (PCC) is an advanced ignition strategy that has been shown to enhance spark ignition (SI) engine combustion stability by providing distributed ignition sites from turbulent jets. PCC has been proven especially advantageous compared to SI in dilute and ultra-lean operating conditions. This work involves experimental and computational investigation of the effects of varying pre-chamber geometry on pre-chamber and main chamber combustion under simulated exhaust gas recirculation dilution conditions in a heavy-duty, single-cylinder, optically accessible natural gas engine at stoichiometric fuel-air ratio. Pre-chambers with varying nozzle number (5 – 12), diameter (1.3 – 2.5 mm), and nozzle angle (0 – 20°) are examined, keeping the nozzle area to pre-chamber internal volume (A/V) ratio constant. Pressure-based diagnostics are used to probe pre-chamber and subsequent main chamber combustion, and optical diagnostics including high-speed OH* chemiluminescence and

Dhotre, Akash, Nyrenstedt, Gustav, Rajasegar, Rajavasanth, Varma, Arun, Northrop, William, Singh, Satbir, Srna, Ales

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

2025-01-8351To be published on 04/01/2025

Sustainable alternative fuels can reduce the carbon footprint of compression-ignition (CI) internal combustion engine powered vehicles. However, the diversity of ignition behavior in these fuels poses a challenge to achieving robust and efficient engine operation. Specifically, low cetane fuels with poor ignitability exhibit highly variable combustion phasing and torque production unless fuel is injected earlier during compression. The tradeoff is that earlier fuel 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 asymmetrical combustion phasing 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

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

Experimental and Numerical Investigation of Different Dilution Techniques in a High-Performance H2 - Fueled SI Engine

2025-01-8424To be published on 04/01/2025

Nowadays Hydrogen (H2) fueled Internal Combustion Engine (ICE) can be considered a promising solution for high performance applications since it allows carbon free combustion process. At the same time, H2-ICE can reach similar performance and driving experience of gasoline engines. Compared to gasoline, Hydrogen combustion, in stoichiometric conditions, shows a higher flame speed, a lower ignition energy and a lower quenching distance. Mainly for these reasons H2 combustion is characterized by a high risk of abnormal combustion (Knock and Pre-Ignition), relevant NOx emissions and high heat losses. On the other hand, the high flammability range and high combustion stability of H2 allow the use of different techniques to reduce combustion reactivity. This work presents a combined approach experimental and numerical in order to assess the benefits and the disadvantages of each method. The experimental campaign, in different operating conditions, was carried out on a production derived

Tonelli, Roberto, Medda, Massimo, Gullino, Fabrizio, Silvestri, Nicola, Zaffino, Francesco, Mariconti, Roberto, Rossi, Vincenzo

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

2025-01-8004To be published on 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

Combustion and Emission performance of Acid-catalysed Butanol Alcoholysis derived advanced biofuel Blends from a compression ignition engine

2025-01-8445To be published on 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 EN 590 (on-road), and 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

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

Numerical Investigation of Fuel Injection Strategies for Ammonia-Diesel Dual-fuel Engine

2025-01-8368To be published on 04/01/2025

This study numerically investigates ammonia-diesel dual fuel combustion in a heavy-duty engine. Detailed and reduced reaction mechanisms are validated against experimental data to develop injection timing maps aimed at maximizing indicated thermal efficiency (ITE) while mitigating environmental impacts using stochastic reactor model (SRM). The equivalence ratio, ammonia energy share (AES), injection timing, and engine load are varied to optimize combustion efficiency and minimize emissions. The results demonstrate that advancing injection timing reduces ITE due to heightened in-cylinder temperatures, resulting in increased heat losses through walls and exhaust gases. Maximum chemical efficiency is observed at an equivalence ratio near 0.9 but decreases thereafter, influenced by ammonia’s narrow flammability range. Emission analysis highlights significant reductions in Global Warming Potential (GWP) and Eutrophication Potential (EP) with higher AES, driven by decreased CO2 and nitrogen

Karenawar, Shivraj Anand, YADAV, Neeraj Kumar, Maurya, Rakesh Kumar

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

2025-01-8381To be published on 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

Effect of Hydrogen Addition on Abnormal Combustion of Pre-Chamber Natural Gas Engine at High Load

2025-01-8426To be published on 04/01/2025

In cogeneration system, the pre-chamber natural gas engine adopts combustion technologies such as ultra-highly supercharged lean burn and Miller cycle to increase the theoretical efficiency by increasing the specific heat ratio and the mechanical efficiency by improving the specific power. In recent years, the use of hydrogen fuel has been attracting attention in order to achieve carbon neutrality, and it is required to operate existing high-efficiency natural gas engines by appropriately mixing hydrogen. For this purpose, it is important to have a natural gas and hydrogen co-combustion technology that allows combustion at any mixture ratio without major modifications. The authors mixed hydrogen into the fuel of an ultra-highly supercharged lean burn pre-chamber natural gas engine (Bore size: 200mm) that has already achieved high efficiency, and performed combustion experiments at a brake mean effective pressure of 2 MPa or more. The engine load and hydrogen mixture ratio were used as

Morikawa, Koji, Kimura, Shin, Sakai, Shunya, Moriyoshi, Yasuo

Effects of lubricant oil loss on efficiencies and carbon emissions in Argon Power Cycle hydrogen-fueled engines

2025-01-8436To be published on 04/01/2025

The trend of internal combustion engines is reducing or eliminating carbon emissions and improve the overall efficiency. The Argon Power Cycle (APC) hydrogen-fueled engine, specifically, can improve the thermal efficiency by using Argon as the working substance. At the same time, due to the utilization of hydrogen and pure oxygen, the combustion of the fuel in APC hydrogen-fueled engines produces zero carbon or NOx. However, during engine operation, lubricate oil consumption can still generate CO2 and becomes the only source for emission. Furthermore, the accumulation of CO2 under closed cycle can impede the condensation recovery of Argon and reduce the efficiency. In this study, a computational model was used to analyze the piston ring dynamics and surrounding gas flow in an APC hydrogen-fueled engine at a net indicated thermal efficiency of 62.4% (gross indicated thermal efficiency of 58.6%), and to investigate the effect of lubricate oil loss on the efficiency and carbon emissions

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

Numerical Investigation of Injector Cap Design on Hydrogen Jet Characteristics

2025-01-8463To be published on 04/01/2025

Hydrogen internal combustion engines are emerging as a promising technology for decarbonizing the transportation sector. However, due to hydrogen's low density, achieving sufficient fuel delivery often requires a high flow rate. Despite its excellent diffusivity, optimizing the hydrogen-air mixing in the context of an engine combustion chamber remains a significant challenge. This mixing process critically influences key phenomena such as ignition, flame propagation, knocking, and oxides of nitrogen formation, all of which are shaped by injector design, injection parameters, and in-cylinder flow characteristics. The Injector caps have been found to be useful for providing more control over injection from hollow-cone injectors, which deliver high flow rates, offering the advantage of not needing to modify the entire injector system. Therefore, modeling and understanding the impact of injector cap designs on jet evolution is essential to improving efficiency in heavy-duty engines. In

Zaihi, Abdullah, Moreno Cabezas, Kevin, Liu, Xinlei, Ben Houidi, Moez, Wu, Hao, AlRamadan, Abdullah, Cenker, Emre, Mohan, Balaji, Roberts, William, Im, Hong

A study on cetane on demand technology part 1 - Development of fuel reformer to improve fuel ignitability

2025-01-8447To be published on 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. Also, gasoline components produced via Fischer-Tropsch (FT) synthesis exhibit low octane numbers, rendering them suitable for this combustion concept. In the current situation where low-octane gasoline is not widely available in the market, onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. This requires Cetane on Demand technology, which enables compression ignition combustion with both commercial gasoline and low-octane gasoline. It is known that the ignition property of fuel is enhanced when the fuel is oxidized to generate peroxides. Moreover, the use of N-hydroxyphthalimide (NHPI) as a catalyst promotes peroxide generation at low temperatures. The objective of this

Hashimoto, Kohtaro, Yamada, Yoshikazu, Matsuura, Katsuya, Kudo, Tomohide, Chishima, Hiroshi, Al-Taher, Maryam, Kalamaras, Christos, Albashrawi, Reem

Performance and Emissions Analysis of a Hydrogen-Powered Heavy-Duty High Compression Ratio SI Engine Across Various Loads and speed at ultra-lean condition

2025-01-8428To be published on 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

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

2025-01-8352To be published on 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-plugbased 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

Experimental Study of Glow Plug Assisted Methanol Compression Ignition

2025-01-8412To be published on 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

Ignition and Combustion Improvement via Ignition Modulation under Flow Conditions

2025-01-8403To be published on 04/01/2025

In order to reduce the environmental impact of transportation, the adoption of low and zero carbon fuel is needed to reduce the greenhouse gas emissions from engines, both from tailpipe and well-to-wheel perspectives. However, for some of the promising fuels, such as renewable natural gas and ammonia, the relatively low chemical reactivity and laminar flame speed bring challenge to a rapid and efficient combustion process, especially under lean or diluted conditions to suppress NOx emissions, leading to reduced combustion and thermal efficiencies. To tackle the challenge, high in-cylinder turbulence intensity is needed to shorten the combustion duration, together with strong ignition sources to support the initial flame kernel development. In this paper, an ignition energy modulation system is developed to enhance both discharge duration and discharge energy of a spark event to secure the ignition process. Moreover, a rapid compression machine is employed to compress the fuel-air

Jin, Long, Yu, Xiao, Zhou, Qing, Reader, Graham, Li, Liguang, Zheng, Ming

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

2025-01-8397To be published on 04/01/2025

The shift to electromobility is accelerating, but 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

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

Development of the Tour Split-Cycle Internal Combustion Engine

2025-01-8394To be published on 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

Enhancing Dual Fuel Combustion Simulation: A Novel Geometric Approach for Accurate Flame Entrainment Estimation

2025-01-8366To be published on 04/01/2025

Maritime transport plays a key role in the EU economy and stands as one of the most energy-efficient transportation modes. However, it is a significant and growing source of greenhouse gas emissions. In Europe, maritime transport accounts for 3 to 4% of the EU's total 〖CO〗_2 emissions, which was over 124 million tonnes of 〖CO〗_2 in 2021. These emissions are anticipated to rise to 130% of 2008 levels by 2050. To reduce greenhouse gas emissions from maritime transport, the European Union has set targets to reduce emissions by 6% by 2030 and by 80% by 2050. A promising way to achieve these targets is to use renewable fuels in marine engines. Fuels such as hydrogen or methanol can serve as the primary energy source in internal combustion (IC) engines. However, their high autoignition temperatures require an external ignition source to start combustion in compression ignition (CI) engines. The Dual Fuel (DF) approach offers an effective method for incorporating these fuels. Due to the time

Parsa, Somayeh, Daenens, Arthur, Verschaeren, Roel, Dierickx, Jeroen, Verhelst, Sebastian

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

2025-01-8383To be published on 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

Experimental investigation between pre-ignition, knocking, vibration and performance in an internal combustion engine

2025-01-8380To be published on 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

An experimental investigation of the liquid jet breakup characteristics in a vaporizer under equivalent operating conditions of a microturbine combustion chamber

2025-01-8458To be published on 04/01/2025

This study experimentally investigates the liquid jet breakup process in a vaporizer of a microturbine combustion chamber under equivalent operating conditions, including temperature and air mass flow rate. A high-speed camera experimental system, coupled with an image processing code, was developed to analyze the jet breakup length. The fuel jet is centrally positioned in a vaporizer with an inner diameter of 8mm. Airflow enters the vaporizer at controlled pressures, while thermal conditions are maintained between 298 K and 373 K using a PID-controlled heating system. The liquid is supplied through a jet with a 0.4 mm inner diameter, with a range of Reynolds numbers (Reliq=2300-3400), and aerodynamic Weber numbers (Weg=4-10), corresponding to the membrane and/or fiber breakup modes of the liquid jet. Based on the results of jet breakup length, a new model has been developed to complement flow regimes by low Weber and Reynolds numbers. The analysis of droplet size distribution

ha, Nguyen, Quan, Nguyen, Manh, Vu, Pham, Phuong Xuan

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

2025-01-8643To be published on 04/01/2025

Sound Pollution has become one of the major environmental concerns for global automotive industry in the current era. 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 heard at snorkel. The objective of this work is to correlate low frequency engine order noise prediction at 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. Commercial 1D simulation software GT-POWER, Simcenter 3D and Hypermesh is used for this work. Transmission loss results with respect to frequency of air-box with ducts and intake manifold with charge air cooler are plotted from 0 to 1000 Hz. The air intake system shows good correlation between 3D and 1D till 600 Hz. Compressor and snorkel noise results, especially the firing order and its harmonic orders are

Dixit, Manish, K, Srinivasan

Combustion and Emissions Improvement of Engine Idling via Advanced Ignition Strategies

2025-01-8404To be published on 04/01/2025

Future transportation requires a variety of propulsion systems, using sustainable and renewable energy sources with low carbon footprints. Spark ignition engines remain effective power systems for automotive applications, especially for light and medium-duty applications. However, SI engines are susceptible to excess emissions during engine cold start, as the in-cylinder temperature is low, which leads to unstable ignition and incomplete combustion. More effective and more reliable ignition sources, e.g., with properly modulated and elevated energy, become more favorable for engine cold start. The research results from the author’s lab show that the spark current boost is an effective way to stabilize the spark plasma, increase the discharge energy, and improve the flame kernel development. In addition, recent research results from the author’s lab indicate that the current boost ignition system can provide robust ignition control under low load and lean limit conditions, where

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

Virtual Evaluation of Ceramic Glow Plug Design using Multiphysics Simulation Approach

2025-01-8367To be published on 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 phase because of crack formation. Root cause analysis is performed in this study to understand the reasons of the cracking of the glow plug

Karmakar, Nilankan, orban, Hatem

Data-driven Modeling and Control for Multi-Fuel Compression Ignition Engine

2025-01-8349To be published on 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 a lot of 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

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

2025-01-8360To be published on 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. Two engines with different characteristics were used for comparison, a low turbulent port fuel injected single-cylinder CFR engine and a high turbulent direct injected engine

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

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

2025-01-8465To be published on 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

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

2025-01-8444To be published on 04/01/2025

In petroleum-based fuels, the combination of low-octane gasoline and a compression ignition combustion system has been proposed to reduce Well-to-Wheel CO2 emissions of automobiles. The gasoline components produced by FT synthesis have a low octane number, making them suitable for this combustion concept. In the current situation where low-octane gasoline is not widely available in the market, onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. This requires Cetane on Demand Technology, which enables compression ignition combustion with both commercial gasoline and low-octane 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. Using N-hydroxyphthalimide (NHPI)-supported ZSM-5 as a catalyst, commercial gasoline was

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

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

2025-01-8429To be published on 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 both iso-octane and gasoline 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

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

Optical Investigation of DI Hydrogen Jets and Jet-Wall Interactions Under Engine-like Conditions

2025-01-8456To be published on 04/01/2025

Direct injection (DI) hydrogen internal combustion engines are a promising technology for sustainable energy due to hydrogen's high energy content and potential for zero-carbon emissions. A key factor in improving the performance of these engines is understanding how hydrogen jets interact with the walls of the combustion chamber, as this affects fuel-air mixing and combustion efficiency. When hydrogen jets hit the walls, they undergo various processes like reflection and dispersion, which are influenced by factors such as injection pressure, wall temperature, and chamber design. To study these jet-wall interactions under high-pressure and high-temperature conditions, Schlieren shadowgraphy was used because it allows for real-time, high-resolution imaging of the jet behavior without interfering with the process. The experiment focused on how hydrogen jets interact with flat and curved metal surfaces placed at different heights inside a constant volume spray chamber

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

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

2025-01-8415To be published on 04/01/2025

Study examines the energy breakdown from the combustion of 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. The paper focuses on one the operating point of 2000rpm - 100Nm, important representative points in the FTP certification cycle. For each fuel mixture, conditions tested include sweep of boost, EGR and injection pressure. Tests are conducted at same combustion timing, of CA10 at -1 deg ATDC, with the engine controller operating with a real-time combustion feedback based on in-cylinder sampling of pressure. Trends of NOx, HC, and CO, are similar for 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 stoichiometric to lean resulted in about 3-5% increase on cycle efficiency. Fuel injection pressures resulted in about 1% gain per 200bar. EGR is effective in reducing NOx but has

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

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

2025-01-8409To be published on 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. It introduces a control strategy termed "oil-gas" control coupling quasi-homogeneous mixture multi-pulse charge activity control. The findings indicate that a quasi-homogeneous mixture can be achieved through single direct injection of gasoline during the suction stroke, with low injection pressure enhancing charge activity and promoting stable combustion. The optimal injection timing is identified at approximately -315 CA ATDC, which corresponds to peak thermal efficiency. The multi-pulse charge activity control strategy effectively regulates the heat release rate

Nie, JinLong, Yi, Yucheng

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

2025-01-8422To be published on 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 potentially carbon neutrality by 2045. However, as the volumetric concentration of hydrogen 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 hydrogen 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 fourth generation Tour split-cycle engine was undertaken while operating on 100% methane and various hydrogen/methane fuel blends (30%, 40

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

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