Browse Topic: Air / fuel ratio

Items (1,426)

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

Exploring the Effects of Varying Pre-Chamber Geometry in a Heavy-Duty Natural Gas Optical Engine under Dilution Conditions

2025-01-8407

04/01/2025

Pre-chamber combustion is an advanced ignition strategy that has been shown to enhance spark ignition (SI) combustion stability in natural gas (NG) engines by providing distributed ignition sites from turbulent jets and enhancing main-chamber turbulence. Pre-chamber combustion has been proven especially advantageous compared to SI in ultra-lean and dilute operating conditions. This work involves experimental investigation of the effects of varying passive pre-chamber nozzle configuration on pre-chamber and main chamber combustion under simulated exhaust gas recirculation (EGR) dilution (0 and 20%) conditions in a heavy-duty, single-cylinder, optically accessible NG engine at stoichiometric fuel-air ratio. Pre-chamber nozzle configurations include four pre-chambers with constant nozzle area to pre-chamber volume ratio (A/V) with different nozzle sizes and orientations and one configuration with larger nozzles. The optical engine is operated in a skip-fire sequence consisting of 18

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

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 Comparison of Stoichiometric and Lean Burn Ammonia-Hydrogen Co-Fuelling in a Modern Spark Ignition Engine

2025-01-8432

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 ammonia’s 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

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

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

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

Ignition and Combustion Improvement Via Ignition Modulation under Flow Conditions

2025-01-8403

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 flow speed 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 current and discharge energy of a spark event to secure the ignition process. Moreover, a rapid compression machine is employed to compress the fuel-air mixture to the

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

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 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

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

AFR Adaptation Strategy Based on Lambda Sensor for a Methanol Engine

2025-01-7039

01/31/2025

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

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

Flash Boiling Impact on Spray, Flame, Emissions, and Soot of Gasoline-Acetone-Butanol-Ethanol Blend at Simulated Cold-Start GDI Operation Using a CVCC

2025-01-7046

01/31/2025

The use of carbon-neutral fuels instead of conventional fuels in gasoline direct injection (GDI) engines is beneficial to global decarbonization. However, the application of renewable non-petroleum fuels in GDI engines is still unclear due to their different physicochemical properties. Acetone-Butanol-Ethanol (ABE) is a promising low-carbon alternative fuel for GDI engines, but its high viscosity and latent heat cause pool firing during cold start. The existing flash boiling technology can solve this problem. This study explores the effects of flash boiling on spray characteristics, flame propagation, soot, and emissions of gasoline-ABE blend in a constant volume combustion chamber (CVCC) without airflow. Optical windows, high-speed camera recording, in-chamber pressure measurement, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscope (TEM) were used to analyze flame spreading, combustion characteristics, exhaust gases, and soot morphology. Flash boiling

Nour, Mohamed, Zhang, Weixuan, Cui, Mingli, Li, Xuesong, Xu, Min, Qiu, Shuyi

Study of Soot Generation in Hybrid Engines during Cold Start and Low-Load Conditions Using an Optical Engine

2025-01-7047

01/31/2025

As regulations regarding vehicle emissions and fuel consumption become increasingly stringent, the development of hybrid power systems is accelerating, primarily due to their benefits in fuel efficiency and reduction of pollutants. Hybrid engines are specially designed to operate optimally at mid to high speeds and loads. But for low-speed low-load conditions, due to the relatively low in-cylinder tumble intensity and lower injection pressure, the fuel-air mixture tends to deteriorate, resulting in an increase in particle number. To enable the engine to reach optimal RPM and load quickly during frequent start-stop cycles, hybrid engines typically set a higher startup engine speed and establish fuel rail pressure more quickly compared to traditional engines. Yet hybrid engines still encounter challenges of soot generation during cold start conditions. Especially in urban driving conditions where the hybrid engine frequently experiences startups and idling, the soot generation problem

Liu, Changye, Man, Xingjia, Cui, Mingli, Liang, Yuanfei, Wang, Shangning, Li, Xuesong

A Comparative Study of Combustion and Performance in Diesel Engines Fueled by Mosambi Peel Biodiesel-Butylated Hydroxytoluene Nanoparticles Blend

2024-01-5258

01/28/2025

This study’s objective is to examine the combustion and performance of mosambi waste peel biodiesel (MWPB) combined with butylated hydroxytoluene (BHT) nanoparticles as a substitute fuel for diesel engines. It also aims to assess the impact of this blend on engine combustion, such as in-cylinder pressure, heat release rate (HRR), ignition delay (ID), combustion duration (CD) and mass fraction burnt (MFB) and performance indicators, including brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), engine torque, exhaust gas temperature (EGT), indicated mean effective pressure (IMEP), air-fuel ratio (A/F ratio) and volumetric efficiency, while also considering the feasibility of employing waste materials in fuel generation. The experimental configuration utilized a research diesel engine functioning under standard conditions, emphasizing the maintenance of uniform injection pressure to ensure optimal fuel atomization and combustion. The test fuels are diesel, MWPB, MWPB

Jayabal, Ravikumar, Madhu, S., Devarajan, Yuvarajan, Domian, Christopher Selvam

Jet-Induced Compression Ignition (JICI)—Application of Spark-Assisted Compression Ignition (SACI) in a Combustion System with Active Pre-Chamber

03-18-01-0009

01/17/2025

The application of short burn durations at lean engine operation has the potential to increase the efficiency of spark-ignition engines. To achieve short burn durations, spark-assisted compression ignition (SACI) as well as active pre-chamber (PC) combustion systems are suitable technologies. Since a combination of these two combustion concepts has the potential to achieve shorter burn durations than the application of only one of these concepts, the concept of jet-induced compression ignition (JICI) was investigated in this study. With the JICI, the fuel is ignited in the PC, and the combustion products igniting the charge in the main combustion chamber (MC) triggered the autoignition of the MC charge. A conventional gasoline fuel (RON 95 E10) and a Porsche synthetic fuel (POSYN) were investigated to assess the fuel influence on the JICI. Variations of the relative air/fuel ratio in the exhaust gas (λex) were performed to evaluate both the occurrence of the JICI and the dilution

Burkardt, Patrick, Günther, Marco, Villforth, Jonas, Pischinger, Stefan

Large-Bore HFO Engine Gas Conversion for Power Plants – Part A: Numerical Assessment

2024-36-0160

12/20/2024

In the global scenario marked by the increasing environmental awareness and the necessity on reducing pollutant emission to achieve the decarbonization goals, action plans are being proposed by policy makers to reduce the impact of the climate change, mainly affecting the sectors that most contribute to CO2 emissions such as transportation and power generation. In this sense, by virtue of the National Energy Plan 2050, the Brazilian market will undergo the decommissioning of thermal power plants fueled by diesel and heavy fuel oil (HFO) by 2030, compromising about 6.7 GW of power capacity according to the Brazilian Electricity Regulatory Agency (ANEEL) database. An alternative to the scrapping of these engine power plants is their conversion to operate with fuels with a lower carbon footprint, such as the natural gas. This work, therefore, aims to numerically assess the conversion feasibility of a HFO large bore four-stroke turbocharged engine to operate with natural gas by means of a

Gonçalves, Vinícius Fernandez, Zabeu, Clayton Barcelos, Antolini, Jácson, Salvador, Roberto, Almeida, Rogério, Valiati, Allan Soares, Filho, Guenther Carlos Krieger

Performance and Emissions Analysis Using Ducted Fuel Injection in Compression Ignition Engine with Load Variation

2024-36-0154

12/20/2024

Despite the increasing electrification of current vehicles, Diesel engines will continue to be used for several decades to come. There is still a need to introduce emission control technologies, especially those that show good potential and do not require extensive engine modifications. The increasing focus on reducing pollutant emissions and improving energy efficiency has prompted engine manufacturers to continuously strive for technological progress. The aim is to ensure compliance with environmental regulations and the fulfillment of social expectations. Specifically, new Diesel engine projects face the challenge of minimizing both nitrogen oxides (NOx) and soot emissions, which requires significant investiment in research to develop innovative combustion methods and exhaust gas treatment. One of these innovative methods is Ducted Fuel Injection (DFI), which aims to reduce emissions by improving spray development to obtain a better mixture at flame upstream. This study presents an

Dias, Fábio Jairo, dos Santos, Leila Ribeiro, Rufino, Caio, Garcia, Ezio Castejon, Lomonaco, Raphael, Argachoy, Celso, Lacava, Pedro Teixeira

Response Surface Methodology-Based Multi-Objective Optimization for Biofuel-Powered Engine Response Map Development under the Steady-State Operating Conditions

03-17-08-0063

12/20/2024

The twin challenges of the automotive industry namely petroleum dependence and environmental pollution paved way for the development of an environmentally friendly and feasible substitute for diesel, possessing power characteristics equivalent to those of a diesel engine. Biofuel has potential as a renewable energy source, offering a more sustainable alternative to traditional fossil fuels. However, it does come with some challenges, such as varying quality and combustion properties. To enhance its performance, engines can be fine-tuned by adjusting fuel injection parameters, such as timing, pressure, and duration. Accordingly, this research article focuses on optimizing the fuel injection parameters for a CRDi engine powered by D+LPO (20% lemon peel oil and 80% diesel) biofuel, with the goal of improving both performance and emission characteristics. The experimental design matrix was generated using Design Expert-13 software, employing the I-optimal technique. Utilizing response

Saiteja, Pajarla, Ashok, B.

Data Quality Evaluation and Assurance of Emissions on IC Engine

2024-28-0134

12/05/2024

Engines are the predominant source of Earth’s air pollution contributor, hence there are various emission laws which mandate the use of emission test cycle to verify that engine adhere to predetermined emission limits. A protocol found in an emission standard that enables consistent and comparable measurement of exhaust emissions for various engines is known as an emission test cycle. The values of emission parameters are the result of emission cycle. Measurements of GHG (Green House Gas) emissions - particulate number and particulate matter, carbon monoxide, total hydrocarbon, and nitrogen oxides are used to determine exhaust gas thermodynamic characteristics, fuel-air ratio, combustion efficiency, and emission indices, as they link engine performance to environmental impact. The engine and after-treatment system’s exhaust emissions are currently having a significant negative impact on the environment. The emission indices (EI) are the characteristics that engine engineers and

Baraskar, Shweta, Rajopadhye, Sunil, Dhuri, Santosh, Patil, Rahul, Mudassir, Mohammed, Phadke, Abhijit Narahari, Mokhadkar, Rahul

Numerical Evaluation of Fuel-Air Mixing in a Direct-Injection Hydrogen Engine Using a Multi-Hole Injector

2024-01-4295

11/05/2024

Hydrogen as a chemical energy carrier is considered as one of the most promising options to achieve effective decarbonization of the transportation sector, due to its carbon-free chemical composition. This is particularly true for applications that rely on internal combustion engines (ICEs), although much research is still needed to achieve stable, reliable, and safe operations of the engine. To this purpose, direct injection (DI) of gaseous hydrogen during the compression stroke offers great potential to avoid backfire and largely reduce preignition issues, as opposed to port-fuel injection. Recently, much research has been dedicated, both experimentally and numerically, to understanding the physics and chemistry connected with hydrogen’s mixing and combustion processes in ICEs. This work presents a computational fluid dynamics (CFD) study of the hydrogen DI process in an optical engine operating at relatively low tumble conditions. Gaseous hydrogen pressurized at 86 bar is introduced

Torelli, Roberto, Wu, Bifen, Park, Ji-Woong, Pei, Yuanjiang

Performance and Emissions of a Hydrogen Dual-Fuel Engine Using Diesel and HVO as Pilot Fuels

2024-01-4286

11/05/2024

A comprehensive experimental study of hydrogen–diesel dual-fuel and hydrogen-hydrotreated vegetable oil (HVO) dual-fuel operations was conducted in a single-cylinder diesel engine (bore 85.0 mm, stroke 96.9 mm, and compression ratio 14.3) equipped with a common rail fuel injection system and a supercharger. The hydrogen flow rate was manipulated by varying the hydrogen excess air ratio from 2.5 to 4.0 in 0.5 increments. Hydrogen was introduced into the intake pipe using a gas injector. Diesel fuel and HVO were injected as pilot fuels at a fixed injection pressure of 80 MPa. The quantity of pilot fuel was set to 3, 6, and 13 mm3/cycle. The intake and exhaust pressures were set in the range of 100–220 kPa in 20 kPa increments. The engine was operated at a constant speed of 1,800 rpm under all conditions. The pilot injection timing was varied such that the ignition timing was constant at the TDC under all conditions. The results demonstrated that smoke was lower when HVO was used as the

Mukhtar, Ghazian Amin, Tange, Kota, Nakatani, Satoshi, Horibe, Naoto, Kawanabe, Hiroshi, Morita, Gin, Hiraoka, Kenji, Koda, Kazuyuki

Comparison of Different Injector Nozzles for the Utilization of Polyoxymethylene Dimethyl Ethers

2024-01-4297

11/05/2024

Oxygenated substances are a promising approach in the field of alternative fuels. A current example of such a fuel are Polyoxymethylene Dimethyl Ethers (OME). With their physical and chemical properties, alternative fuels like OME pose new challenges for diesel engine injection systems. As the heating value is low compared to conventional Diesel fuel, measures must be taken to increase the amount of fuel injected. Possible solutions include increasing the nozzle hole diameter, the injection pressure, and the number of nozzle holes. All mentioned adaptions have an influence on the mixture formation and make it necessary to examine the injection process in detail also with regard to phenomena such as cavitation. In this study, three passenger car Diesel injector nozzles are compared, two of which are adapted in terms of nozzle hole diameter (increase by 20%) and number of nozzle holes (increase from 8 to 12) in order to increase the mass flow rate of fuel to the required elevated level

Riess, Sebastian, Fuchs, Thorsten, Strauß, Lukas, Günthner, Michael, Wensing, Michael

Operation of a Compression-Ignition Kerosene Aviation Engine with Sustainable Aviation Fuel: An Experimental Study

2024-01-6005

10/28/2024

The aviation industry is undergoing environmental scrutiny due to its significant greenhouse gas emissions. Sustainable aviation fuels (SAFs) are a vital solution for reducing carbon emissions and pollutants, aligning with global efforts for carbon-neutral aviation growth. SAFs can be produced via multiple production routes from different feedstock, resulting in significantly different physical and chemical fuel properties. Their suitability in a compression-ignition (CI) aircraft engine was evaluated through test bench investigations at TU Wien - Institute of Powertrain and Automotive Technology in partnership with Austro Engine. ASTM D7566-certified fuels like Hydrotreated Vegetable Oil (HVO), Fischer–Tropsch–Kerosene (FTK) or Alcohol to Jet (AtJ), but also an oxygen containing biodiesel have been tested extensively. Gaseous emissions, soot emissions, indication measurement data, efficiencies, and the like were acquired and comprehensively analyzed for engine operation with different

Kleissner, Florian, Hofmann, Peter

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

2024-01-5095

10/15/2024

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

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

Enhancing Homogeneity and Combustion Efficiency in Gas Engines: A Novel Approach through Swirl-Inducing Air Intake Pipe Modifications

2024-24-0039

09/18/2024

The lack of a homogeneous air-fuel mixture in internal combustion engines is a major cause of pollutant emissions, such as carbon monoxide (CO) and hydrocarbons (HC). This paper focuses on the design, simulation, and testing of a modified air intake pipe for a gas engine, incorporating deflectors to induce a swirl effect in the air-fuel mixture. To determine the optimal configuration for the deflectors and the diameter of the air intake pipe, several Computational Fluid Dynamics (CFD) simulations were conducted. The best results were then tested on a real gas engine. The primary objective of this study is to offer a solution for increasing the homogeneity level of the air-fuel mixture in gas engines, without requiring significant changes to engine components. In this case, achieving this goal involves only relatively small modifications to the air intake pipe. The results indicate that the swirl effect effectively enhances the homogeneity of the air-fuel mixture by generating higher

Gutierrez, Marcos, Taco, Diana

Load-Exchange Optimization for a Passive Pre-Chamber Ignition System

2024-24-0034

09/18/2024

Increasing ignition energy by replacing standard spark igniters with pre-chambers is an established combustion accelerator. With rapid combustion on the one hand, mixture dilution can be extended while maintaining the combustion stability at adequate levels. On the other hand, accelerated combustion reduces the need for knock-induced spark retarding, thus facilitating emission reduction and increases in efficiency simultaneously. A newly developed pre-chamber ignition system is introduced in this work. The influence of the system on combustion is investigated in a single-cylinder research engine. The findings can support the development of future ignition technology for passenger-vehicle-sized engines. There are two basic configurations of pre-chamber igniters: the first is known as passive pre-chamber, the second as scavenged pre-chamber. The first configuration can be realized as a simple replacement for standard spark plugs. While additional costs are minimized, the air-fuel ratio

Fellner, Felix, Fitz, Patrick, Härtl, Martin, Jaensch, Malte

Modeling and Experimental Validation of a Pure Methanol-Fueled Small SI Engine: Impact of the Laminar Flame Speed Correlation

2024-24-0033

09/18/2024

In a context of growing concern for vehicle-related CO2 and pollutant emissions, non-conventional fuels like methanol (CH3OH) represent a valid alternative to fossil fuels to decarbonize the transport sector in a reasonable time. This is mainly due to its lower carbon content than conventional gasoline and diesel. Moreover, methanol can be obtained either from biomass or CO2 capture from the atmosphere, which makes the latter a renewable fuel. Given the possibility of being stored in liquid phase at standard temperature and pressure (STP), methanol is very suitable for Light Duty Vehicles (LDVs), in which the need to contain fuel tank dimensions is relevant. Regarding the deployment of methanol as a fuel, it is not very challenging, as it can be adopted in current production Internal Combustion Engines (ICEs) either in pure form or in blend with other fuels without any significant modifications. Within this context, the present work aims to assess, in both experimental and simulation

Frasci, Emmanuele, Sementa, Paolo, Arsie, Ivan, Vaglieco, Bianca Maria

Performance Analysis of Hydrogen Combustion under Ultra Lean Conditions in a Spark Ignition Research Engine Using a Barrier Discharge Igniter

2024-24-0036

09/18/2024

The global push to minimize carbon emissions and the imposition of more rigorous regulations on emissions are driving an increased exploration of cleaner powertrains for transportation. Hydrogen fuel applications in internal combustion engines are gaining prominence due to their zero carbon emissions and favorable combustion characteristics, particularly in terms of thermal efficiency. However, conventional Spark-Ignition (SI) engines are facing challenges in meeting performance expectations while complying with strict pollutant-emission regulations. These challenges arise from the engine's difficulty in handling advanced combustion strategies, such as lean mixtures, attributed to factors like low ignition energy and abnormal combustion events. To address these issues, the Barrier Discharge Igniter (BDI) stands out for its capability to generate non-equilibrium Low-Temperature Plasma (LTP), a strong promoter of ignition through kinetic, thermal, and transport effects. Its surface

Avana, Massimiliano, Ricci, Federico, Papi, Stefano, Zembi, Jacopo, Battistoni, Michele, Grimaldi, Carlo N.

A Computational Study of Hydrogen Direct Injection Using a Pre-Chamber in an Opposed-Piston Engine

2024-01-3010

07/02/2024

Combustion characteristics of a hydrogen (H2) direct-injected (DI) pre-chamber (PC)-assisted opposed piston two-stroke (OP2S) engine are investigated by 3D computational fluid dynamics (CFD) simulations. The architecture of the OP2S engine has potential features for reducing wall heat losses, as the DI H2 jets are not directed towards the piston face. To overcome the high resistance to autoignition of H2, a PC technology was implemented in order to enhance the ignition of the mixture by the multiple hot reactive jets. To further investigate the interaction between the H2 plume and the chamber walls, three different piston bowl designs were evaluated and ranked based on a merit function. For the cases under study, the flat piston design was found to be most favorable (compared to the narrow and wide pistons) due to its reduced surface area for lower wall heat losses. The results also showcase that a co-optimization approach considering various parameters is an effective strategy to

Menaca, Rafael, Moreno Cabezas, Kevin, Shakeel, Mohammad Raghib, Vorraro, Giovanni, Turner, James W. G., Im, Hong G.

Benefits of Supercharger Boosting on H ₂ ICE for Heavy Duty Applications

2024-01-3006

07/02/2024

The fast acceleration of GHG (CO2 in particular) emitted by human activities into the atmosphere is accelerating the average temperature increase of our globe causing heavy climate change. This phenomenon has triggered a strong pressure on GHG emission reduction in all the human activities including the transportation sector which contributes for the 29% to the total emissions in EU [1]. A mitigation to this tendency can come from synthetic fuels: when produced by using clean energy, they can be considered CO2 neutral. H2 is the building block of synthetic fuels and can be used in spark ignited engines where releases the energy accumulated during its production. This solution is particularly attractive for HD applications thanks to the high energy density. H2 can be burned in a quite wide range of λ, but staying on 2,2 the amount of engine out NOx will be low enough for the use on a 13L engine with a relatively simple aftertreatment system. This λ value is difficult to maintain in the

Andrisani, Nicola, Bagal, Nilesh

Application of MAN Loop Scavenging in a 125 cc Two-Stroke Racing Engine

SAE-PP-0039505/08/2024

The use of MAN-type loop scavenging port arrangements in a 125 cc two-stroke racing engi-ne is being investigated. These make it possible to provide larger cross-sections for the trans-fer ports, but at the expense of the exhaust port cross-section. The investigation is carried out using 1D calculations with GT-Suite. It is shown that significantly higher maximum outputs are possible in this way. However, this requires large exhaust widths, as otherwise the exhaust port is too small and the advantage of the larger transfer cross-section is overcompensated. Mixed forms between the original MAN loop scavenging and Schnürle loop scavenging can represent a good compromise. One open point is the quality of the scavenging. A study found in the literature on the use of MAN loop scavenging on a small engine shows significantly worse results than is known from large engines. There is still a need for further investigation here.

Eilts, Peter

Determination of Air–Fuel Ratio at 1 kHz via Mid-Infrared Laser Absorption and Fast Flame Ionization Detector Measurements in Engine-Out Vehicle Exhaust

03-17-05-0039

04/29/2024

Measurements of air–fuel ratio (AFR) and λ (AFRactual/AFRstoich) are crucial for understanding internal combustion engine (ICE) performance. However, current λ sensors suffer from long light-off times (on the order of seconds following a cold start) and limited time resolution. In this study, a four-color mid-infrared laser absorption spectroscopy (LAS) sensor was developed to provide 5 kHz measurements of temperature, CO, CO2, and NO in engine-out exhaust. This LAS sensor was then combined with 1 kHz hydrocarbon (HC) measurements from a flame ionization detector (FID), and the Spindt exhaust gas analysis method to provide 1 kHz measurements of λ. To the authors’ knowledge, this is the first time-resolved measurement of λ during engine cold starts using the full Spindt method. Three tests with various engine AFR calibrations were conducted and analyzed: (1) 10% lean, (2) stoichiometric, and (3) 10% rich. The measurements were acquired in the exhaust of a light-duty truck with an 8

Stiborek, Joshua W., Kempema, Nathan J., Schwartz, Charles J., Szente, Joseph J., Loos, Michael J., Goldenstein, Christopher S.

Hydrogen Injection Position Impact: Experimental Analysis of Central Direct Injection and Side Direct Injection in Engines

03-17-05-0038

04/18/2024

A detailed investigation was carried out on the performance, combustion, and emissions of a single-cylinder direct injection hydrogen spark ignition (SI) engine with either a side-mounted direct injection (SDI) or a centrally installed direct injection (CDI) injector. The first part of the study analyzed the performance and emissions characteristics of CDI and SDI engine operations with different injection timings and pressures. This was followed by comparing the engine’s performance and emissions of the CDI and SDI operations at different engine speeds and relative air-to-fuel ratios (lambda) with the optimized injection pressure and timings. Furthermore, the performance and emission attributes of the hydrogen engine with the CDI and SDI setups were conducted at a fixed λ value of 2.75 across a broad spectrum of engine loads. The study’s main outcome demonstrates that both direct injection systems produced near-zero CO2, CO, and HC emissions. Stable engine operations could be achieved

Mohamed, Mohamed, Mirshahi, Milad, Jiang, Changzhao, Zhao, Hua, Harrington, Anthony, Hall, Jonathan

Ultra-Downsizing of ICEs Based on True Atkinson Cycle Implementations. Thermodynamic Analysis and Comparison on the Indicated Fuel Conversion Efficiency of Atkinson and Classical ICE Cycles

2024-01-2096

04/09/2024

Ultra-Downsizing (UD) was introduced as an even higher level of downsizing for Internal Combustion Engines ICEs, see [2] SAE 2015-01-1252. The introduction of Ultra Downsizing (UD) aims to enhance the power, efficiency, and sustainability of ICEs while maintaining the thermal and mechanical strain within acceptable limits. The following approaches are utilized: 1 True Atkinson Cycles are implemented utilizing an asymmetrical crank mechanism called Variable Compression and Stroke Ratios (VCSR). This mechanism allows for extended expansion stroke and continuous adjustment of the Volumetric Compression Ratio (VCR). 2 Unrestricted two or more stage high-pressure turbocharging and intensive intercooling: This setup enables more complete filling of the cylinder and reduces the compression work on the piston, resulting in higher specific power and efficiency. 3 The new Load Control (LC) approach is based to continuous VCR adjustment. By adjusting the VCR without resorting to excessive

Gheorghiu, Victor

Modeling Pre-Chamber Assisted Efficient Combustion in an Argon Power Cycle Engine

2024-01-2690

04/09/2024

The Argon Power Cycle (APC) is a novel zero-emission closed-loop argon recirculating engine cycle which has been developed by Noble Thermodynamics Systems, Inc. It provides a significant gain in indicated thermal efficiency of the reciprocating engine by breathing oxygen and argon rather than air. The use of argon, a monatomic gas, greatly increases the specific heat ratio of the working fluid, resulting in a significantly higher ideal Otto cycle efficiency. This technology delivers a substantial improvement in reciprocating engine performance, maximizing the energy conversion of fuel into useful work. Combined Heat and Power (CHP) operating under the APC represents a promising solution to realize a net-zero-carbon future, providing the thermal energy that hard-to-electrify manufacturing processes need while at the same time delivering clean, dispatchable, and efficient power. Since the working fluid in an APC is synthetic, the concentration of argon, oxygen, fuel, and carbon dioxide

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

CFD Modeling of Conventional and Pre-Chamber Ignition of a High-Performance Naturally Aspirated Engine

2024-01-2102

04/09/2024

The abatement of carbon dioxide and pollutant emissions on motorbike spark-ignition (SI) engines is a challenging task, considering the small size, the low cost and the high power-to-weight ratio required by the market for such powertrain. In this context, the passive pre-chamber (PPC) technology is an attractive solution. The combustion duration can be reduced by igniting the air-fuel mixture inside a small volume connected to the cylinder, unfolding the way to high engine efficiencies without penalization of the peak performance. Moreover, no injectors are needed inside the PPC, guaranteeing a cheap and fast retrofitting of the existing fleet. In this work, a 3D computational fluid dynamics (CFD) investigation is carried out over an experimental configuration of motorbike SI engine, operated at fixed operating conditions with both traditional and PPC configurations. The employed CFD methodology is based on a unique flamelet-based combustion model, regardless the selected ignition

Nodi, Alessandro, Sforza, Lorenzo, Lucchini, Tommaso, Onorati, Angelo, Buttitta, Marco, Marmorini, Luca

Numerical Simulation of Ammonia-Hydrogen Engine Using Low-Pressure Direct Injection (LP-DI)

2024-01-2118

04/09/2024

Ammonia (NH3), a zero-carbon fuel, has great potential for internal combustion engine development. However, its high ignition energy, low laminar burning velocity, narrow range of flammability limits, and high latent heat of vaporization are not conducive for engine application. This paper numerically investigates the feasibility of utilizing ammonia in a heavy-duty diesel engine, specifically through low-pressure direct injection (LP-DI) of hydrogen to ignite ammonia combustion. Due to the lack of a well-corresponding mechanism for the operating conditions of ammonia-hydrogen engines, this study serves only as a trend-oriented prediction. The paper compares the engine's combustion and emission performance by optimizing four critical parameters: excess air ratio, hydrogen energy ratio, ignition timing, and hydrogen injection timing. The results reveal that excessively high hydrogen energy ratios lead to an advanced combustion phase, reducing indicated thermal efficiency. Additionally

Xu, Xiaoting, Wang, Wei, Qi, Yunliang, Wang, Zhi, Min, Haijiao, Li, Fangwei, Yin, Yong, Li, Zhi

Effect of Baffle Height on the in-Cylinder Air-Fuel Mixture Preparation in a Gasoline Direct Injection Engine – A Computational Fluid Dynamics Analysis

2024-01-2697

04/09/2024

In-cylinder fluid dynamics enhance performance and emission characteristics in internal combustion (IC) engines. Techniques such as helical ports, valve shrouding, masking, and modifications to piston profiles or vanes in ports are employed to achieve the desired in-cylinder flows in these engines. However, due to space constraints, modifications to the cylinder head are typically minimal. The literature suggests that introducing baffles into the combustion chamber of an IC engine can enhance in-cylinder flows, air-fuel mixing, and, subsequently, stratification. Studies have indicated that the height of the baffles plays a significant role in determining the level of improvement in in-cylinder flow and air-fuel mixing. Therefore, this study employs Computational fluid dynamics (CFD) analysis to investigate the impact of baffle height on in-cylinder flow and air-fuel mixing in a four-stroke, four-valve, spray-guided gasoline direct injection (GDI) engine. The maximum allowable baffle

V, Vishal, Mallikarjuna, J M

Effect of Timing Strategy on Mixture Formation, Performance and Emission of Inlet Injection Hydrogen Engine

2024-01-2614

04/09/2024

In order to scrutinize the timing variables impacting the combustion performance and emissions of the Port Fuel Injection hydrogen engine (PFI-H2ICE), a model of a four-cylinder hydrogen engine is meticulously built utilizing the 1D software GT-POWER. The effect of excess air coefficients and timing strategies (including the intake valve opening timing (IVO), the start of injection timing (SOI), and ignition timing) is analyzed in this study. The main conclusions are as follows: The hydrogen engine remold from the Isuzu JE4N28 nature gas engine manifests a lean combustion threshold ranging between 2.0 and 2.5. Notably, advancing intake valve opening timing by 20°CA has proven beneficial to the brake thermal efficiency (BTE) of the hydrogen engine while reducing the NOx emissions by a substantial margin, and advancing intake valve opening timing bears the virtue of strengthen the positive influence of the start of injection timing upon the engine's combustion performance. The longer the

Hu, Zhiyuan, Yin, Li, Zhang, Yunhua, Lou, Diming, Tan, Piqiang, Liu, Dengcheng

A Three-Way Catalyst Model for a Bio-Methane Heavy-Duty Engine: Characterization at Different Lambda

2024-01-2084

04/09/2024

Given the spread of natural gas engines in low-term toward decarbonization and the growing interest in gaseous mixtures as well as the use of hydrogen in Heavy-Duty (HD) engines, appropriate strategies are needed to maximize thermal efficiency and achieve near-zero emissions from these propulsor systems. In this context, some phenomena related to real-world driving operations, such as engine cut-off or misfire, can lead to inadequate control of the Air-to-Fuel ratio, key factor for Three-Way Catalyst (TWC) efficiency. Goal of the present research activity is to investigate the performance of a bio-methane-fueled HD engine and its Aftertreatment System (ATS), consisting of a Three-Way Catalyst, at different Air-to-Fuel ratio. An experimental test bench characterization, in different operating conditions of the engine workplan, was carried out to evaluate the catalyst reactivity to a defined pattern of the Air-to-Fuel ratio. Through the detection of key performance parameters and

Di Maio, Dario, Guido, Chiara, Napolitano, Pierpaolo, Beatrice, Carlo

Numerical Study on the Design of a Passive Pre-Chamber for a Heavy-Duty Hydrogen Combustion Engine

2024-01-2112

04/09/2024

Lean-burn hydrogen internal combustion engines are a good option for future transportation solutions since they do not emit carbon-dioxide and unburned hydro-carbons, and the emissions of nitric-oxides (NOx) can be kept low. However, under lean-burn conditions the combustion duration increases, and the combustion stability decreases, leading to a reduced thermal efficiency. Turbulent jet ignition (TJI) can be used to extend the lean-burn limit, while decreasing the combustion duration and improving combustion stability. The objective of this paper is to investigate the feasibility of a passive pre-chamber TJI system on a heavy-duty hydrogen engine under lean-burn conditions using CFD modelling. The studied concept is mono-fuel, port-fuel injected, and spark ignited in the pre-chamber. The overall design of the pre-chamber is discussed and the effect of design parameters on the engine performance are studied. From this analysis, it was found that the volume of the pre-chamber and the

Maas, Ralph, Bekdemir, Cemil, Somers, Bart

Effect of In-Cylinder Flow Motion on Fuel-Air Mixture Formation in a Medium-Duty DI-SI H2 Engine: An Experimentally Supported CFD Study

2024-01-2117

04/09/2024

The increased utilization of batteries and fuel-cells for powering electric applications, as well as bio- and e-fuels into internal combustion engines are seen as options to lower the carbon footprint of industry and transportation sectors. When high power outputs and fast refueling are requisites, H2 ICEs may be a relevant choice. Applications include electricity conversion within a genset or mechanical energy in a vehicle. Within this framework, a John Deere 4045 Diesel engine converted to a H2 single-cylinder is studied at relevant operating conditions for the mentioned use cases, which pose high torque and power output requirements. The modified engine integrates a Phinia DI-CHG 10 outward-opening H2 injector instead of the Diesel unit, as well as a spark-plug rather than the glow-plug. To explore the effects of in-cylinder air flow on the H2-air mixing, two piston designs are employed: one conserves the intake generated swirl; the other contains deflectors promoting a more complex

Mota Ferreira, João, Oung, Richard, Foucher, Fabrice

Research on the Pollutant Reduction Control for P2.5 Hybrid Electric Vehicles

2024-01-2376

04/09/2024

The strategy for emission reduction in the P2.5 hybrid system involves the optimization of engine torque, engine speed, catalyst heat duration, and motor torque regulation in a coordinated manner. In addition to employing traditional engine control methods used in HEV models, unique approaches can be utilized to effectively manage emissions. The primary principle is to ensure that the engine operates predominantly under steady-state conditions or limits its load to regulate emissions levels. The main contributions of this paper are as follows: The first is the optimization of catalyst heating stage. During the catalyst heating stage, the system divides it into one or two stages. In the first stage, the vehicle is driven by the motor while keeping the engine idle. This approach stabilizes catalyst heating and prevents fluctuations in air-fuel ratio caused by speed and load changes that could potentially worsen emissions performance. The second stage corresponds to when the engine-driven

Jing, Junchao, Liu, Yiqiang, Sun, Jiazhen, Wang, Zhentao, Zhang, Junzhi

Experimental Investigation of Internal and External EGR Effects on a CNG-OME Dual-Fuel Engine

2024-01-2361

04/09/2024

Dual-fuel engines powered by renewable fuels provide a potential solution for reducing the carbon footprint and emissions of transportation, contributing to the goal of achieving sustainable mobility. The investigation presented in the following uses a dual-fuel engine concept running on biogas (referred to as CNG in this paper) and the e-fuel polyoxymethylene dimethyl ether (OME). The current study focuses on the effects of exhaust gas rebreathing and external exhaust gas recirculation (EGR) on emissions and brake thermal efficiency (BTE). A four-cylinder heavy-duty engine converted to dual-fuel operation was used to conduct the engine tests at a load point of 1600 min-1 and 9.8 bar brake mean effective pressure (BMEP). The respective shares of high reactivity fuel (HRF, here: OME) and low reactivity fuel (LRF, here: CNG) were varied, as were the external and internal EGR rates and their combinations. CNG was injected into the intake manifold to create a homogeneous air-fuel mixture

Jost, Ann-Kathrin, Guenthner, Michael, Weigel, Alexander

Development of Ammonia Direct Injection 4-Cylinder Spark-Ignition Engine

2024-01-2818

04/09/2024

As the carbon neutrality to reduce greenhouse gas emissions has become a global movement, the development of power sources using carbon-free fuels is an essential task for the industry. Accordingly, many companies in various fields that need carbon reduction are striving to develop power sources and build energy value chains using carbon-free or carbon-neutral fuels such as hydrogen and E-fuel. Ammonia, which is also a carbon-free fuel, stands as an efficient energy vector delivering high energy density and flexibility in transportation and storage, capable of mitigating hydrogen’s key drawbacks. However, difficulty of controlling combustion of ammonia due to its fuel characteristics limited the development of internal combustion engines using ammonia to the basic research stage in the limited operating conditions. Hyundai Motor Company presents the development of ammonia fueled 4-cylinder SI engine using direct injection strategy, designed based on 2.5L LPG T-DI engine. It is the

Min, Chan ki, Lee, Seung Woo, Baek, Hong-Kil

Ammonia as a Green and Zero Carbon Dioxide Internal Combustion Engine Fuel

2024-26-0080

01/16/2024

Most of the vehicles with internal combustion engines worldwide use fossil fuels. The widely used fuels available on the market are gasoline, diesel, and CNG. These fuels are getting costlier every year while at the same time generating pollutants through exhaust gases. Hence in the market, electric vehicles are effectively providing pollution-free solutions in the passenger car and lightweight carrier vehicle segments. However, the off-road, heavy-duty, and stationary applications with high load factors, are in general less favorable for battery electric scenarios since frequent charging will be mandatory and time-consuming. Hence, for these applications, the replacement of an internal combustion engine is quite difficult. There are various renewable fuels like ammonia, methanol, and biodiesel under research tests and study. As these are renewable fuels, the cost of these fuels can be lowered during mass production. Here, the idea of ammonia as an alternate fuel is discussed, which

Khan, Rizwan, Güdden, Arne, Mulukutla, Kiran, Alam, Mohammad Mansoor

Numerical analysis of the influence of SOI and injection duration on the homogenization of hydrogen-air mixtures in a PFI SI engine under lean operation

2023-36-0106

01/08/2024

The use of green hydrogen as a fuel for internal combustion engines is a cleaner alternative to conventional fuels for the automotive industry. Hydrogen combustion produces only water vapor and nitrogen oxides, which can be avoided with ultra-lean operation, thus, eliminating carbon emissions, from a tank-to-wheel perspective. In this context, the aim of this study is to investigate the influence of hydrogen injection timing and duration on the homogeneity of the hydrogen-air mixtures. Computational fluid dynamic (CFD) simulations were performed to analyze the distribution of air-fuel ratios along the engine's combustion chamber. The simulation software was CONVERGE 3.0, which offers the advantage of automatic mesh generation, reducing the modeling efforts to adjusting the operating conditions of the studied case. Before comparing the injection parameters, a mesh independence test was conducted along with model validation using experimental data. To properly evaluate the start of

Pasa, Bruno Roberto, Fagundez, Jean Lucca Souza, Martins, Mario Eduardo Santos, Salau, Nina Paula Gonçalves, Cogo, Vitor Vielmo, Prante, Geovane Alberto Frizzo, Wittek, Karsten

Investigating the Effects of Dethrottling on the Combustion and Efficiency of a Spark-Ignition Engine Powered by Hydrogen

2023-36-0128

01/08/2024

The use of green hydrogen as a fuel is a promising solution for reducing greenhouse gas emissions from our current fleet of petrol-fueled vehicles. However, achieving zero emissions remains a challenge due to the higher relative air-to-fuel ratio (lambda) required to avoid NOx formation during periods of increased load demand. On the other hand, the capability of hydrogen combustion to use a lean mixture with lower combustion variability presents a great advantage. In such cases, thermal efficiency can be improved by reducing pumping work through leaning the mixture and dethrottling to maintain the same load. This study investigates the efficiency and combustion parameters of hydrogen spark ignition operation while maintaining a constant load at several intake pressure conditions. Tests were conducted on a Ricardo Proteus spark ignition single-cylinder research engine to evaluate the impact of throttle aperture on pumping work and combustion parameters. The results of this study

Silveira, Juliano Pereira, Roso, Vinícius Rückert, Salau, Nina Paula Gonçalves, Martins, Mario Eduardo Santos, Lanzanova, Thompson Diórdinis Metzka

ZERO-EMISSION INTERNAL COMBUSTION ENGINE

SAE-PP-0036811/17/2023

A new concept of internal combustion engine has been developed. The purpose is to have an engine that can burn hydrocarbon fuels without discharging any greenhouse gas or other harmful substances into the atmosphere. The new engine, the zero-emission engine, inducts no air from the environment. Instead, the engine exhaust gas, with added oxygen, is used in performance of the combustion cycle. Carbon dioxide, the main byproduct of combustion is captured, stored, and unloaded during refueling for further storage, sequestration, or recycling. The zero-emission engine displacement can be significantly smaller than in a conventional air-inducting engine of equal power, with a significantly higher power density. The engine is unthrottled and it can operate with a much higher compression ratio without an increase in the cylinder temperature. The above concept also envisions recycling the captured carbon dioxide by using it with water to produce hydrocarbon fuel and oxygen that can be supplied

Schechter, Michael, schechter, victor

Ammonia Emissions from Combustion in Gasoline Engines

2023-01-1655

10/31/2023

Forthcoming worldwide emissions regulations will start regulating ammonia emissions from light duty vehicles. At present, most light duty vehicles are powered by gasoline spark ignition engines. Sources of ammonia emission from such engines can be in-cylinder reactions (i.e. combustion) or downstream reactions across aftertreatment devices, particularly three-way catalysts. The latter has been known to be a major source of ammonia emissions from gasoline vehicles and has been extensively investigated. The former (combustion), less so, and thus is the subject of this work. A two-zone thermodynamic spark ignition engine model with a comprehensive chemical kinetics framework (C3MechV3.3 mechanism), after being validated against experimental ammonia emissions data, is used to study ammonia formation during combustion. Reaction pathways responsible for its generation are analysed and the effects of changing the following engine operational and combustion parameters are explored: engine load

Bajwa, Abdullah, Shankar, Varun, Leach, Felix

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