Browse Topic: Exhaust gas recirculation (EGR)

Items (2,710)

Investigation of the effects of Injection strategy on the combustion performance and emissions of Light Duty GCI engine

2024-01-4279To be published on 11/05/2024

High-efficiency lean-burn compression ignition using high-reactivity fuels, known as Gasoline Compression Ignition (GCI), demonstrates potential in reducing particulate matter (PM) and nitrogen oxide (NOx) emissions by controlling the charge ignition through both local strength and auto-ignition chemistry. This study explores the combustion strategy for GCI fuel with a Research Octane Number (RON) of 61 under a wide range of operating conditions using a Single Cylinder Research Engine (SCRE) calibrated to Euro 5 emission standards. The SCRE, with a compression ratio (CR) of 16.50, is designed for high-reactivity fuels and features a centrally located multi-hole injector and a piston bowl shape tailored to injection and spray characteristics. At steady state and part load (IMEP = 7 bar), the study investigates the impact of fuel injection strategy and the required amount of exhaust gas recirculation (EGR). Findings indicate that a single injection strategy with a considerable amount of

Qahtani, Yasser Al, Raman, Vallinayagam, Viollet, Yoann, Alhajhouje, Abdullah, Cenker, Emre, AlRamadan, Abdullah

Evaluation of Jetfire ^® Pre-Chamber Ignition for Lean, DI Homogeneous Charge, Heavy Fueled Combustion and Multi-Fuel Capability

2024-01-4134

09/16/2024

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Nicklowitz, Daniel, Stuecken, Thomas, Schock, Harold, Higel, Jennifer

Computer-Aided Engineering Approach to Optimize Hydroformed Exhaust Gas Recirculation Tube under Thermal Load

2024-01-5086

08/30/2024

This study emphasizes the importance of computer-aided engineering (CAE) approach in optimizing exhaust gas recirculation (EGR) tube under thermal load. With exhaust gases generating high temperatures, the EGR tube experiences increased stress and strain, posing challenges to its structural integrity. Moreover, the cyclic heating and cooling cycles of the engine imposes thermal fatigue, further compromising the tube’s performance over time. To address these concerns, the paper introduces a comprehensive CAE methodology for conducting factor of safety analysis. The nonlinear thermal analysis is performed on the assembly as due to high temperatures the stresses cross the yield limit. The strain-based approach is used to calculate the factor of safety. Moreover, a comprehensive case study is presented, illustrating how design modifications can enhance the thermal fatigue factor of safety. By adjusting parameters such as thickness and routing, engineers can mitigate thermal stresses and

Munde, Ganesh, Chattaraj, Sandip, Hatkar, Chandan, Godse, Rushikesh

Premixed Dual-Fuel Combustion of Camelina sativa Oil and Ethanol

03-18-01-0001

08/06/2024

Dual-fuel (DF) engines enable efficient utilization of a low reactivity fuel (LRF), usually port-injected, and a high reactivity fuel (HRF) provided directly into the cylinder. Ethanol and Camelina sativa oil can be ecologically effective but not fully recognized alternatives for energy production using modern CI engines equipped with a common rail system and adopted for dual fueling. The high efficiency of the process depends on the organization of the combustion. The article describes the premixed dual-fuel combustion (PDFC) realized by dividing the Camelina sativa dose and adjusting its injection timing to the energetic share of ethanol in the DF mixture. The injection strategy of HRF is crucial to confine knock, which limits DF engine operation, but the influence of EGR is also important. The research AVL engine’s dual-fueling tests focused on combustion process modification by the proposed injection strategy and cooled EGR at different substitution rates. For all examined points

Pawlak, Grzegorz, Skrzek, Tomasz, Kosiuczenko, Krzysztof, Płochocki, Patryk, Simiński, Przemysław

Optimization of Hydroformed Exhaust Gas Recirculation Tube under Vibrational Load by Finite Element Analysis

2024-01-5062

06/17/2024

This study emphasizes the importance of CAE approach in optimizing EGR tube under vibrational load. EGR tube is a weak link in the EGR system and chances of failure due to vibration and relative displacement of mating parts, i.e., overhang or improper support at exhaust manifold, intake manifold, or EGR system. Consideration of the mating parts for the EGR tube is very important to get the realistic resonance frequencies, otherwise it could have some different results in the CAE, which will deviate from the reality. So, it’s important to study the dynamic response on the EGR tube, which needs to be taken care during the design phase. This paper aims to optimize the EGR tube under vibrational load by using CAE techniques and the industry experience as a product expertise. some critical parameter such as damping is very important during the CAE, which can be generated by doing the rigorous testing and how it affects the stress and correspondingly FOS. CAE model of EGR tube is created on

Munde, Ganesh, Chattaraj, Sandip, Hatkar, Chandan, Thakur, Abhishek Kumar

Influence of Intake Charge Temperature and EGR Rate on the Combustion and Emission Characteristics of Ammonia/Diesel Dual-Fuel Engine

2024-37-0025

06/12/2024

Ammonia has emerged as a promising carbon-free alternative fuel for internal combustion engines (ICE), particularly in large-bore engine applications. However, integrating ammonia into conventional engines presents challenges, prompting the exploration of innovative combustion strategies like dual-fuel combustion. Nitrous oxide (N2O) emissions have emerged as a significant obstacle to the widespread adoption of ammonia in ICE. Various studies suggest that combining exhaust gas recirculation (EGR) with adjustments in inlet temperature and diesel injection timing can effectively mitigate nitrogen oxides (NOx) emissions across diverse operating conditions in dual-fuel diesel engines. This study conducts a numerical investigation into the impact of varying inlet charge temperatures (330K, 360K, and 390K) and EGR rates (0%, 10%, and 20%) on the combustion and emission characteristics of an ammonia/diesel dual-fuel engine operating under high-load conditions, while considering different

Hoseinpour, Marziyeh, Karami, Rahim, Salahi, Mohammad Mahdi, Mahmoudzadeh Andwari, Amin, Gharehghani, Ayat, Garcia, Antonio

The Potential of Hydrogen High Pressure Direct Injection toward Future Emissions Compliance: Optimizing Engine-Out NOx and Thermal Efficiency

2024-37-0005

06/12/2024

By building on mature internal combustion engine (ICE) hardware combined with dedicated hydrogen (H2) technology, the H2-ICE has excellent potential to accelerate CO2 reduction. H2-ICE concepts can therefore contribute to realizing the climate targets in an acceptable timeframe. In the landscape of H2-ICE concepts, pilot-ignited High Pressure Direct Injection (HPDI™) is an attractive option considering its high thermal efficiency, wide load range and its applicability to on-road as well as off-road heavy-duty equipment. Still, H2-HPDI is characterized by diffusion combustion, giving rise to significant NOx emissions. In this paper, the potential of H2-HPDI toward compliance with future emissions legislation is explored on a 1.8L single-cylinder research engine. With tests on multiple load-speed points, Exhaust Gas Recirculation (EGR) was shown to be an effective measure for reducing engine-out NOx, although at the cost of a few efficiency points. Furthermore, the use of EGR was

Willems, Robbert, Seykens, Xander, Bekdemir, Cemil, Doosje, Erik, Van Gompel, Peter

Combustion Analysis of Active Pre-Chamber Design for Ultra-Lean Engine Operation

03-17-05-0040

04/27/2024

In this article, the effects of mixture dilution using EGR or excessive air on adiabatic flame temperature, laminar flame speed, and minimum ignition energy are studied to illustrate the fundamental benefits of lean combustion. An ignition system developing a new active pre-chamber (APC) design was assessed, aimed at improving the indicated thermal efficiency (ITE) of a 1.5 L four-cylinder gasoline direct injection (GDI) engine. The engine combustion process was simulated with the SAGE detailed chemistry model within the CONVERGE CFD tool, assuming the primary reference fuel (PRF) to be a volumetric mixture of 93% iso-octane and 7% n-heptane. The effects of design parameters, such as APC volume, nozzle diameter, and nozzle orientations, on ITE were studied. It was found that the ignition jet velocity from the pre-chamber to the main chamber had a significant impact on the boundary heat losses and combustion phasing. The simulation showed that, under 16.46 compression ratio (CR) and

Peethambaram, Mohan Raj, Zhou, Quanbao, Waters, Benjamin, Pendlebury, Ken, Fu, Huiyu, Haines, Andrew, Hale, David, Hu, Tiegang, Zhang, Jiaxiang, Wu, Xuesong, Zhang, Xiaoyu

3-Dimensional Numerical Simulation and Research on Internal Flow about Different EGR Rates in Venturi Tube of EGR System for a Turbocharged Diesel Engine

2024-01-2418

04/09/2024

Exhaust gas recirculation technology is one of the main methods to reduce engine emissions. The pressure of the intake pipe of turbocharged direct-injection diesel engine is high, and it is difficult to realize EGR technology. The application of Venturi tube can easily solve this problem. In this paper, the working principle of guide-injection Venturi tube is introduced, the EGR system and structure of a turbocharged diesel engine using the guide-injection Venturi tube are studied. According to the working principle of EGR system of turbocharged diesel engine, the model of guide-injection Venturi tube is established, the calculation grid is divided, and it is carried out by using Computational Fluid Dynamics method that the three-dimensional numerical simulation of the internal flow of Venturi tube under different EGR rates injection. The flow field state, velocity field, pressure field and exhaust gas concentration parameters of the mixture formed by air and EGR exhaust gas in Venturi

Yang, Shuai, Yan, Kai, Liu, Haifeng, Liu, Hairan, Li, Tong

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

Life Cycle Assessment of a State-of-the-Art Diesel powered Engine and Preliminary Evaluation of its Conversion into a Novel Hydrogen powered Engine

2024-01-2442

04/09/2024

This paper is part of a broader research project aiming at studying, designing, and prototyping a hydrogen-powered internal combustion engine to achieve fast market implementation, reduced greenhouse gas emissions, and sustainable costs. The ability to provide a fast market implementation is linked to the fact that the technological solution would exploit the existing production chain of internal combustion engines. Regarding the technological point of view, the hydrogen engine will be a monofuel engine re-designed based on a diesel-powered engine. The redesign involves specific modifications to critical subsystems, including combustion systems, injection, ignition, exhaust gas recirculation, and exhaust gas aftertreatment. Notably, adaptations include the customization of the cylinder head for controlled ignition, optimization of camshaft profiles, and evaluation of the intake system. The implementation incorporates additive manufacturing for the production of new intake manifolds and

Malagrinò, Gianfranco, Accardo, Antonella, Costantino, Trentalessandro, Pensato, Michele, Spessa, Ezio

Next Generation High Efficiency Boosted Engine Concept

2024-01-2094

04/09/2024

This work represents an advanced engineering research project partially funded by the U.S. Department of Energy (DOE). Ford Motor Company, FEV North America, and Oak Ridge National Laboratory collaborated to develop a next generation boosted spark ignited engine concept. The project goals, specified by the DOE, were 23% improved fuel economy and 15% reduced weight relative to a 2015 or newer light-duty vehicle. The fuel economy goal was achieved by designing an engine incorporating high geometric compression ratio, high dilution tolerance, low pumping work, and low friction. The increased tendency for knock with high compression ratio was addressed using early intake valve closing (EIVC), cooled exhaust gas recirculation (EGR), an active pre-chamber ignition system, and careful management of the fresh charge temperature. Engine weight reduction measures were implemented throughout the engine system making use of composite materials, advanced manufacturing techniques, and architectural

Shelby, Michael H., Case, Mark E., Chesney, Lynn A.

Combustion Development and Efficiency Improvement for Hybrid Engines

2024-01-2093

04/09/2024

In the pursuit of carbon emission reduction, hybridization has emerged as a significant trend in powertrain electrification. As a crucial aspect of hybrid powertrain system development, achieving high brake thermal efficiency (BTE) and a wide operating range with high efficiency are essential for hybrid engines to effectively integrate with the hybrid system. When developing dedicated hybrid engines (DHE), several design considerations come into play. First, in order to make efficient use of available resources and enable engine production on the same assembly line as conventional engines, it is crucial to maintain consistency in key design parameters of the cylinder head and block, thus extending the platform-based design approach. Among the key measures to achieve high BTE, cooled exhaust gas recirculation (EGR) has been extensively explored and proven effective in improving efficiency by mitigating knocking and reducing engine cooling heat loss. Fast combustion, acting as a

Xu, Zheng, Qiu, Jie, Zhang, ZiQing, Cheng, Chuanhui, Zhang, YaJun, Yang, Yang, Wang, Yingzhen, Lu, Yuan, Zhou, Zhou, Li, XiaoYang

Performance of Spark Current Boost System on a Production Engine under Lean-Burn Conditions

2024-01-2106

04/09/2024

In order to improve the fuel economy for future high-efficiency spark ignition engines, the applications of advanced combustion strategies are considered to be beneficial with an overall lean and/or exhaust gas recirculation diluted cylinder charge. Stronger and more reliable ignition sources become more favorable under extreme lean/EGR conditions. Existing research indicates that the frequency of plasma restrikes increases with increased flow velocity and decreased discharge current level, and a higher discharge current can reduce the gap resistance and maintain the stretched plasma for a longer duration under flow conditions. An in-house developed current boost control system provides flexible control of the discharge current level and discharge duration. The current boost ignition system is based on a multi-coil system with a discharge current level of 180mA. In this study, a comparative study has been conducted to investigate the efficacy of multi-coil and multi-core ignition

Yu, Xiao, Leblanc, Simon, Wang, Linyan, Zheng, Ming, Tjong, Jimi

Numerical Study of a Six-Stroke Gasoline Compression Ignition (6S-GCI) Engine Combustion with Oxygenated Fuels

2024-01-2373

04/09/2024

A numerical investigation of a six-stroke direct injection compression ignition engine operation in a low temperature combustion (LTC) regime is presented. The fuel employed is a gasoline-like oxygenated fuel consisting of 90% isobutanol and 10% diethyl ether (DEE) by volume to match the reactivity of conventional gasoline with octane number 87. The computational simulations of the in-cylinder processes were performed using a high-fidelity multidimensional in-house 3D CFD code (MTU-MRNT) with improved spray-sub models and CHEMKIN library. The combustion chemistry was described using a two-component (isobutanol and DEE) fuel model whose oxidation pathways were given by a reaction mechanism with 177 species and 796 reactions. The key advantage of six-stroke engine operation is the ability to switch the combustion mode among kinetical controlled mode (KCM), kinetically-driven mixing control mode (K-MCM) and mixing controlled mode (MCM) in the second power stroke (PS2) providing a wider

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

Numerical Study of an EGR Dilution in a Pre-Chamber Spark Ignited Engine Fuelled by Natural Gas

2024-01-2081

04/09/2024

Exhaust gas recirculation (EGR) is a proven strategy for the reduction of NOX emissions in spark ignited (SI) engines and compression ignition engines, especially in lean burn conditions where the increase of thermal efficiency is obtained. The dilution level of the mixture with EGR is in a conventional SI engine limited by the increase of combustion instability (CoV IMEP). A possible method to extend the EGR dilution level and ensure stable combustion is the implementation of an active pre-chamber combustion system. The pre-chamber spark ignited (PCSI) engine enables fast and stable combustion of lean mixtures in the main chamber by utilizing high ignition energy of multiple flame jets penetrating from the pre-chamber to the main chamber. In this paper, as an initial research step, a numerical analysis is performed by employing the 0D/1D simulation model, validated with the initial experimental and 3D-CFD results. The simulation model is used for the prediction of possible benefits of

Dilber, Viktor, Krajnovic, Josip, Ugrinić, Sara, Sjeric, Momir, Tomic, Rudolf, Kozarac, Darko

Combustion Chamber Development for Flat Firedeck Heavy-Duty Natural Gas Engines

2024-01-2115

04/09/2024

The widely accepted best practice for spark-ignition combustion is the four-valve pent-roof chamber using a central sparkplug and incorporating tumble flow during the intake event. The bulk tumble flow readily breaks up during the compression stroke to fine-scale turbulent kinetic energy desired for rapid, robust combustion. The natural gas engines used in medium- and heavy-truck applications would benefit from a similar, high-tumble pent-roof combustion chamber. However, these engines are invariably derived from their higher-volume diesel counterparts, and the production volumes are insufficient to justify the amount of modification required to incorporate a pent-roof system. The objective of this multi-dimensional computational study was to develop a combustion chamber addressing the objectives of a pent-roof chamber while maintaining the flat firedeck and vertical valve orientation of the diesel engine. A new combustion chamber was designed based on a commercial 11-liter natural gas

Hoag, Kevin, Wray, Christopher, Callahan, Timothy J., Lu, Qilong, Gilbert, Ian, Abidin, Zainal

Development of a Direct-Injection Heavy-Duty Hydrogen Engine

2024-01-2609

04/09/2024

Hydrogen-fuelled internal combustion engines (ICEs) offer a zero-carbon fuel option for many applications. As part of the global effort to study hydrogen ICEs Ricardo has developed single-cylinder and multi-cylinder heavy-duty engines. The engines are representative of a 13 litre Euro VI heavy-duty production application converted to run on hydrogen fuel with limited changes. The engine is fitted with direct hydrogen injectors which enable flexible injection strategies and reduce hydrogen in the intake system. Steady-state testing was carried out over an array of speed and load points covering a typical heavy-duty drive-cycle area. Engine test results are presented and analysed in this paper. The combustion system can run to values exceeding lambda 5 and 40% exhaust gas recirculation (EGR) can be tolerated. The impact of lambda, EGR, injection and ignition timing variations are presented and demonstrate how the system responds to the corresponding changes in specific heat capacity

Osborne, Richard, Hughes, John, Loiudice, Angela, Penning, Richard, Valenta, Lukáš

Water Droplet Collison and Erosion on High-Speed Spinning Wheels

03-17-05-0037

04/04/2024

The water droplet erosion (WDE) on high-speed rotating wheels appears in several engineering fields such as wind turbines, stationary steam turbines, fuel cell turbines, and turbochargers. The main reasons for this phenomenon are the high relative velocity difference between the colliding particles and the rotor, as well as the presence of inadequate material structure and surface parameters. One of the latest challenges in this area is the compressor wheels used in turbochargers, which has a speed up to 300,000 rpm and have typically been made of aluminum alloy for decades, to achieve the lowest possible rotor inertia. However, while in the past this component was only encountered with filtered air, nowadays, due to developments in compliance with tightening emission standards, various fluids also collide with the spinning blades, which can cause mechanical damage. One such fluid is the condensed water in the low-pressure exhaust gas recirculation channel (LP-EGR) formulated at cold

Takács, Richárd, Zsoldos, Ibolya, Szentendrei, Dániel

Effect of Turbine Speed Parameter on Exhaust Pulse Energy Matching of an Asymmetric Twin-Scroll Turbocharged Heavy-Duty Engine

02-17-02-0010

03/04/2024

The two-branch exhaust of an asymmetric twin-scroll turbocharged engine are asymmetrically and periodically complicated, which has great impact on turbine matching. In this article, a matching effect of turbine speed parameter on asymmetric twin-scroll turbines based on the exhaust pulse energy weight distribution of a heavy-duty diesel engine was introduced. First, it was built as an asymmetric twin-scroll turbine matching based on exhaust pulse energy distribution. Then, by comparing the average matching point and energy matching points on the corresponding turbine performance map, it is revealed that the turbine speed parameter of energy matching points was a significant deviation from the turbine speed parameter under peak efficiency, which leads to the actual turbine operating efficiency lower than the optimal state. In addition, a turbine speed parameter adjustment strategy was proposed by changing compressor impeller diameters to reveal the effect on turbine matching based on

Jin, Jianjiao, Zhang, Chenyun, Wu, Liangqin, Zhu, Hongping, Qian, Yuanping

Experimental and Numerical Investigation of a Single-Cylinder Methanol Port-Fuel Injected Spark Ignition Engine for Heavy-Duty Applications

2024-26-0072

01/16/2024

With the increasing focus on reducing CO2 emissions to combat global warming and climate change, the automotive industry is exploring near zero-emission alternative fuels to replace traditional fossil-based fuels like diesel, gasoline, and CNG. Methanol is a promising alternative fuel that is being evaluated in India due to its easy transportation and storage, as well as its production scalability and availability potential. This study focuses on the retro-fitment solution of M100 (pure methanol) SI port-fuel injection (PFI) mode of combustion. A heavy duty single-cylinder engine test setup was used to assess methanol SI combustion characteristic. Lean operation strategy has been investigated. At lean mixture conditions a significant drop in NOX and CO emissions was achieved. The fuel injection techniques and the impact of exhaust gas recirculation (EGR) on the conventional stoichiometric combustion process is highlighted. Increase of the EGR ratio at stoichiometric operation led to 3

Singh, Inderpal, Güdden, Arne, Raut, Ankit, Dhongde, Avnish, Emran, Ashraf, Sharma, Vijay, Wagh, Sachin

Engine Modelling with Smart Online DoE

2024-26-0338

01/16/2024

The implementation of TREM/CEV 5 emission norms on farm equipment will bring in cost pressure due to the need for exhaust after treatment systems. This cost increase needs to be reduced by bringing in more efficient and effective processes to shorten the development phase and to provide better fuel efficiencies. In this work ETAS ASCMO Online DoE with Constraint Modelling (ODCM) was applied to execute smart online DoE on a new common rail diesel engine with EGR, whose exact bounds of operation was not available. A Global test plan with ASCMO Static was created without much focus on detailed constraints of engine operation, other than the full load curve. The parameters which were selected were Speed, Torque, Rail Pressure, Main Timing, EGR Valve Position, Pilot Separation and Quantity and Post Quantity and Separation. For these parameters, the safe operating bounds were not available. This ASCMO Static test plan is automated and executed on engine test cell with ETAS INCAFlow. ODCM at

Paulraj, Lemuel Srinivasan, Varsha, Anuroopa, Karadi, Subramanya, Kumar, Devendra

Design and Development of EGR Valve Controller

2024-26-0348

01/16/2024

Various emission and fuel economy norms for passenger cars have been introduced by the government worldwide. In India, meeting each revision of the Bharat Stage (BS) emission standards and Corporate Average Fuel Economy (CAFE) norms is challenging, and requires the incorporation of new technologies into IC engines. One such technology used in gasoline engines is Exhaust gas recirculation (EGR). The entry of dust particles into the EGR system makes it vulnerable to malfunction. One such fleet validation challenge of EGR valve malfunction has been addressed in this study, where the EGR valve became stuck due to dust entry, leading to engine hunting and stalling. The approach followed for the issue resolution demonstrates a method of developing an EGR valve controller for simulating the failure on a bench setup. The controller setup was built around a microcontroller chip that accurately operated the valve with similar logic to that of the vehicle ECU. In addition to operating the valve

Bhatt, Pancham, Kumar, Krishan, Kumar, Sahil

Diesel Emissions and Their Control, Second Edition

R-53312/20/2023

Engineers, applied scientists, students, and individuals working to reduce emissions and advance diesel engine technology will find the second edition of Diesel Emissions and Their Control to be an indispensable reference. Whether readers are at the outset of their learning journey or seeking to deepen their expertise, this comprehensive reference book caters to a wide audience. In this substantial update to the 2006 classic, the authors have expanded the coverage of the latest emission technologies. With the industry evolving rapidly, the book ensures that readers are well-informed about the most recent advances in commercial diesel engines, providing a competitive edge in their respective fields. The second edition has also streamlined the content to focus on the most promising technologies. This book is rooted in the wealth of information available on DieselNet.com, where the "Technology Guide" papers offer in-depth insights. Each chapter includes links to relevant online materials

Majewski, Addy, Jaaskelainen, Hannu

Unlocking the Potential of Water-Blended Karanji Ester and EGR in CI Engines: A Micro-Explosion Effect Investigation

2023-28-0074

11/10/2023

Biodiesel, which is made from the methyl ester of vegetable oils, is becoming more and more popular as an alternative fuel for compression ignition engines because it is good for the environment and can be used as a replacement fuel without making major changes to the engine. Biodiesel offers several key advantages, including its ready availability, environment friendly and its ability to contribute to lower carbondioxide levels in the atmosphere. An exhaust gas recirculation (EGR)-equipped Kirloskar compression ignition engine is used in this research to examine the influence of micro-explosions on the reduction of nitrogen oxides and smoke. The fuel chosen is Karanji oil methyl ester. The experiment involved varying the exhaust gas quantity in increments of 5%, ranging from 5% to 15%, as exhaust gas recirculation (EGR) is recognized as an effective technique for reducing NOx emissions. Similarly, the study also adjusted the water content, ranging from 5% to 15% in 5% increments. It

Sagaya Raj, Gnana, Krupakaran, R L, Natarajan, Manikandan, Pasupuleti, Thejasree, Jeyaseelan, Thangaraja

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

NOx Measurement and Characterization in a Gaseous Fueled High-Pressure Direct-Injection Engine

2023-01-1628

10/31/2023

Heavy-duty (HD) vehicles are a crucial part of the transportation sector; however, strict governmental regulations will require future HD vehicles to meet even more rigid NOx emission standards than what already exist. The use of natural gas (NG) as the primary fuel in HD vehicles can immediately reduce the NOx emissions through lower flame temperatures as compared to traditional diesel and can serve as a precursor to even less carbon intensive fuels as they become more readily available. Pilot ignited direct injection natural gas (PIDING) engine technology is one example of how NG can be used in HD vehicles while maintaining diesel-like efficiency. However, NOx emissions still need to be mitigated to avoid negative air quality effects. Exhaust gas recirculation (EGR) is known to reduce in-cylinder temperatures and thus reduce in-cylinder NOx emissions in diesel engines, but the effects of EGR are not as well understood in PIDING engines. The intent of this study is to develop a better

Hurren, Troy, Kirchen, Patrick

Simulation Study on EGR Condensate Flow and Uniformity of Each Cylinder in the Intake Manifold

2023-01-7034

10/30/2023

As engine technology developed continuously, engine with both turbocharging and EGR has been researched due to its benefit on improving the engine efficiency. Nevertheless, a technical issue has raised up while utilizing both turbocharging and EGR at the same time: excess condensed water existed in intake manifold which potentially trigger misfire conditions. In order to investigate the root-cause, a CFD model (conducted by CONVERGE CFD software) was presented and studied in this paper which virtually regenerated intake manifold flow-field with EGR condensed water inside. Based on the simulated results, it concluded that different initial conditions of EGR condensed water could significantly change the amount of water which deposited in each cylinder. Thus, a coefficient of variation of deposited condensed water amount among these cylinders, was marked as the evaluation reference of cylinder misfire. Theoretically, as this coefficient of variation reduced, the EGR condensed water from

Pan, Shiyi, Li, Guanting, Wang, Jinhua, Zhang, Nan, Xu, Zhiqin, Chen, Shanghua, Chen, Jun, Zhao, Shengwei

Improvement of the EGR Dilution Tolerance in Gasoline Engines by the Use of a HSASI Pre-Chamber Spark Plug

2023-01-1805

10/24/2023

Charge dilution in gasoline engines reduces NOx emissions and wall heat losses by the lower combustion temperature. Furthermore, under part load conditions de-throttling allows the reduction of pumping losses and thus higher engine efficiency. In contrast to lean burn, charge dilution by exhaust gas recirculation (EGR) under stoichiometric combustion conditions enables the use of an effective three-way catalyst. A pre-chamber spark plug with hot surface-assisted spark ignition (HSASI) was developed at the UAS Karlsruhe to overcome the drawbacks of charge dilution, especially under part load or cold start conditions, such as inhibited ignition and slow flame speed, and to even enable a further increase of the dilution rate. The influence of the HSASI pre-chamber spark plug on the heat release under EGR dilution and stoichiometric conditions was investigated on a single-cylinder gasoline engine. The performance of the HSASI spark plug was compared with a passive pre-chamber spark plug

Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland

End-Gas Autoignition Prediction Using Reverse Livengood-Wu Integral with Ignition Delay Time Equations for Gasoline Surrogate Fuel

2023-32-0081

09/29/2023

A high-accuracy knocking or end-gas autoignition prediction model with low computational loads is necessary to develop thermal-efficiency improvement technologies for SI engines efficiently using computational techniques. Livengood-Wu integral has been applied widely as a simple and practical model to predict in-cylinder autoignition timing. In the present study, a high-accuracy model based on Livengood-Wu integral, has been investigated. First, a small set of ignition delay time equations for a premium-gasoline surrogate fuel has been developed, which can reproduce the temperature-, pressure-, equivalence ratio-, and EGR-dependences of ignition delay time under constant-volume condition, produced using a detailed reaction mechanism. Then, Livengood-Wu integral using the ignition delay time equations has been applied to predict in-cylinder autoignition timing produced using the detailed reaction mechanism. Numerical analyses have found X of Livengood-Wu integral and error factors in

Kuwahara, Kazunari

In-cylinder Air Injection for Diesel Combustion Improvement

2023-32-0076

09/29/2023

For further improvement of diesel combustion performance, in-cylinder air injection was applied to enhancing air entrainment in an attempt to shorten the combustion duration. A modified commercially available gasoline injector was used for air injection. The original six-hole nozzle was removed, and a three-hole nozzle (ϕ0.43 mm × 1 hole, ϕ0.5 mm × 2 holes) was used. The air injector was installed near the fuel injection nozzle on a single-cylinder diesel engine, and a performance test was conducted to investigate the effects of the air injection duration, timing, and pressure under the operating conditions of an engine speed of 1200 rpm, fuel injection pressure of 120 MPa, natural aspiration, and without exhaust gas recirculation. In addition, the effects of supplying different gases were considered. Compared with conventional diesel combustion, both air injection and nitrogen injection resulted in a higher peak of the heat release rate, improvement in the indicated work, and decrease

Miyashita, Kazuya, Furukawa, Shinya, Hashimoto, Munemasa, Ishii, Yoshinori, Yamashita, Kenichi

Realization of HCCI Combustion by Internal EGR using CI Engine with Variable Valve Timing System (First Report

2023-32-0021

09/29/2023

The purpose of this study is to cool the internal EGR (Exhaust Gas Recirculation) gas and form a uniform mixture by the injection of fuel into internal EGR gas. In previous studies, the internal EGR has a problem that high-temperature and low-density EGR gas flows into the cylinder and these causes the deterioration of fuel economy and exhaust emission performances [1]. In addition, internal EGR gas collides with fresh air tumble from the intake valves and, distribution of the in-cylinder oxygen concentration becomes heterogeneous. Additionally, the poor volatility of diesel fuel makes it difficult to achieve HCCI combustion in CI (Compression Ignition) engines. In order to resolve these problems, Fuel is injected into the internal EGR gas during the intake stroke. This injection cools the internal EGR gas by high latent heat derived from the promotion of fuel evaporation and equalizes the distribution of oxygen concentration in the cylinder. However, there are few studies on spray

Terada, Masaya, Sumida, Yo, Kawano, Daisuke

A Numerical Model for the Virtual Calibration of a Highly Efficient Spark Ignition Engine

2023-32-0059

09/29/2023

Nowadays numerical simulations play a major role in the development of future sustainable powertrain thanks to their capability of investigating a wide spectrum of innovative technologies with times and costs significantly lower than a campaign of experimental tests. In such a framework, this paper aims to assess the predictive capabilities of an 1D-CFD engine model developed to support the design and the calibration of the innovative highly efficient spark ignition engine of the PHOENICE (PHev towards zerO EmissioNs & ultimate ICE efficiency) EU H2020 project. As a matter of fact, the availability of a reliable simulation platform is crucial to achieve the project target of 47% peak indicating efficiency, by synergistically exploiting the combination of innovative in-cylinder charge motion, Miller cycle with high compression ratio, lean mixture with cooled Exhaust Gas Recirculation (EGR) and electrified turbocharger. Since the engine is expected to operate in highly diluted conditions

ROLANDO, Luciano, MILLO, Federico, CASTELLANO, Giuseppe, TAHTOUH, Toni, ANDRE, Mathieu, BOCCHIERI, Francesco

PREMIER Combustion of Natural Gas Ignited with Diesel Fuel in a Dual Fuel Engine -Effects of EGR and Supercharging on End-gas Auto Ignition and Thermal Efficiency

2023-32-0016

09/29/2023

To control the auto ignition in end-gas region and to achieve higher thermal efficiency in a natural gas dual fuel engine operated under PREMIER combustion mode where the end-gas auto ignition occurs without knocking-like oscillation, the EGR (exhaust gas recirculation) and supercharging were applied. The EGR rate and the intake air pressure as well as the pilot injection timing of diesel fuel were varied, and the profiles of the in-cylinder pressure, the exhaust emissions and the heat balance were examined at the indicated mean effective pressure around 680 kPa. The experimental results showed that higher thermal efficiency can be achieved with the combination of the PREMIER combustion and the EGR rate of 30% due to the improvements in the combustion efficiency and the degree of constant volume heat release while reducing the cooling loss. It was elucidated that the PREMIER combustion with the optimum level of the supercharging maintains the higher combustion efficiency, higher degree

Kobashi, Yoshimitsu, Kishimoto, Kengo, Kawahara, Nobuyuki

Impact of Passive Pre-Chamber Nozzle Diameter on Jet Formation Patterns and Dilution Tolerance in a Constant-Volume Optical Engine

03-17-02-0013

09/11/2023

Pre-chamber jet ignition technologies have been garnering significant interest in the internal combustion engine field, given their potential to deliver shorter burn durations, increased combustion stability, and improved dilution tolerance. However, a clear understanding of the relationship between pre-chamber geometry, operating condition, jet formation, and engine performance in light-duty gasoline injection engines remains under-explored. Moreover, research specifically focusing on high dilution levels and passive pre-chambers with optical accessibility is notably scarce. This study serves to bridge these knowledge gaps by examining the influence of passive pre-chamber nozzle diameter and dilution level on jet formation and engine performance. Utilizing a modified constant-volume gasoline direct injection engine with an optically accessible piston, we tested three passive pre-chambers with nozzle diameters of 1.2, 1.4, and 1.6 mm, while nitrogen dilution varied from 0 to 20%. With

Lee, Dong Eun, Iyer, Claudia, Wooldridge, Steven, Qiao, Li, Yi, Jianwen J.

Effect of Intake Conditions (Temperature, Pressure and EGR) on the Operation of a Dual-Fuel Marine Engine with Methanol

2023-24-0046

08/28/2023

In the upcoming decade sustainable powertrain technologies will seek for market entrance in the transport sector. One promising solution is the utilization of dual-fuel engines using renewable methanol ignited by a pilot diesel fuel. This approach allows the displacement of a significant portion of fossil diesel, thereby reducing greenhouse gas emissions. Additionally, this technology is, next to newbuilds, suited for retrofitting existing engines, while maintaining high efficiencies and lowering engine-out emissions. Various researchers have experimentally tested the effects of replacing diesel by methanol and have reported different boundaries for substituting diesel by methanol, including misfire, partial burn, knock and pre-ignition. However, little research has been conducted to explore ways to extend these substitution limits. Therefore, this study aims to investigate the effects of intake conditions, such as intake air temperature and pressure, and exhaust gas recirculation (EGR

Dierickx, Jeroen, Dejaegere, Quinten, Van Gijzeghem, Andreas, Devos, Stan, De Cock, Berten, Verhelst, Sebastian

Experimental Analysis of a Single-Cylinder Large Bore Engine with External Supercharging in Diesel/CNG Dual-Fuel Mode

2023-24-0058

08/28/2023

The need for a quick reduction in greenhouse gasses and noxious emissions is pushing maritime transportation to increase the use of alternative fuels. Natural Gas (NG) is well recognized as an effective solution to limit the use of marine diesel oil in the short/mid-term. In this scenario, dual-fuel technology is used to enable a conventional diesel engine to operate with a share of gaseous fuel while retaining the capability to run in full diesel mode. Dual-fuel (DF) engines allow the use of natural gas, or biomethane from renewable sources, as the main fuel, with advantages over CO2, SOx and PM emissions with the same levels of NOx. This paper presents an experimental study investigating the effects of the diesel injection strategy on performance and emissions of a dual-fuel, single-cylinder, large bore, 4-stroke engine for marine applications. The engine is equipped with an external supercharging system; NG is injected in the port, while a Common Rail system injects the diesel pilot

De Simio, Luigi, Iannaccone, Sabato, Pennino, Vincenzo, Marchitto, Luca

Comparison of Premixed Fuel and Premixed Charge Operation for Propane-Diesel Dual-Fuel Combustion

2023-24-0059

08/28/2023

With the rising popularity of dual-fuel combustion, liquefied petroleum gas (LPG) can be utilized in high-compression diesel engines. Through production from biomass (biomass to liquid, BtL), biopropane as a direct substitute for LPG can contribute to a reduction in greenhouse gas emissions caused by combustion engines. In a conventional dual-fuel engine, the low reactivity fuel (LRF) propane is premixed with the intake air to form a homogeneous mixture. This air-fuel mixture is then ignited by the high reactivity fuel (HRF) in the form of a diesel pilot injection inside the cylinder. In the presented work, this premixed charge operation (PCO) is compared to a method where propane and diesel are blended directly upstream of the high-pressure pump (premixed fuel operation, PFO) in variable mixing ratios for different engine loads and speeds. Furthermore, the effects of internal and external exhaust gas recirculation are investigated for each operating mode. The results show that PCO

Mueller, Florian, Guenthner, Michael

Assessment of Dilution Options on a Hydrogen Internal Combustion Engine

2023-24-0066

08/28/2023

The hydrogen internal combustion engine is a promising alternative to fossil fuel-based engines, which, in a short time, can reduce the carbon footprint of the ground transport sector. However, the high heat release rates associated with hydrogen combustion results in higher NOx emissions. The NOx production can be mitigated by diluting the in-cylinder mixture with air, Exhaust Gas Recirculation (EGR) or water injected in the intake manifold. This study aims at assessing these dilution options on the emissions, efficiency, combustion performance and boosting effort. These dilution modes are, at first, compared on a single cylinder engine (SCE) with direct injection of hydrogen in steady state conditions. Air and EGR dilutions are then evaluated on a corresponding 4-cylinder engine by 0D simulation on a complete map under NOx emission constraint. On the SCE at 3000rpm and 10.7bar IMEP, air and EGR dilutions allow a high dilution rate, leading to a significant NOx reduction: from 2.8g

Rouleau, Loic, Nowak, Ludovic, Duffour, Florence, Walter, Bruno

Optical Diagnostics to Study Hydrogen/Diesel Combustion with EGR in a Single Cylinder Research Engine

2023-24-0070

08/28/2023

In order to reduce fuel consumption and polluting emissions from engines, alternative fuels such as hydrogen could play an important role towards carbon neutrality. Moreover, dual-fuel (DF) technology has the potential to offer significant improvements in carbon dioxide emissions for transportation and energy sectors. The dual fuel concept (natural gas/diesel or hydrogen/diesel) represents a possible solution to reduce emissions from diesel engines by using low-carbon or carbon-free gaseous fuels as an alternative fuel. Moreover, DF combustion is a possible retrofit solution to current diesel engines by installing a PFI injector in the intake manifold while diesel is injected directly into the cylinder to ignite the premixed mixture. In the present study, dual fuel operation has been investigated in a single cylinder research engine. The engine run at two engine speeds (1500 and 2000 rpm), and hydrogen has been injected in the intake manifold in front of the entrance of the tumble

Mancaruso, Ezio, Rossetti, Salvatore, Vaglieco, Bianca Maria, De Robbio, Roberta, Maroteaux, Fadila

Hydrogen Admixture Strategies for Small-Scale Cogeneration Gas Engines: A Comparison between different Engine Combustion Processes

2023-01-1206

06/26/2023

Cogeneration represents a key element within the energy transition by enabling a balancing of the long-term fluctuations of regeneratives. Regarding the expected increase of hydrogen share in natural gas pipelines in Germany, this work deals with investigations of hydrogen-associated advantages for the lean and stoichiometric operations of natural gas cogeneration engines, in relation to numerous challenges, such as the efficiency-NOx trade-off. Charge dilution is commonly regarded as one of the most effective ways for improving thermal efficiency of spark-ignition gas engines. While excess air serves as a diluent in the lean combustion process, stoichiometric combustion dilution may be obtained by exhaust gas recirculation (EGR). Combining hydrogen addition with mixture dilution is an appealing approach for a better handling of the efficiency-emissions trade-off. The lean and the diluted stoichiometric combustion processes with hydrogen blending were investigated beforehand

Beltaifa, Youssef, Kettner, Maurice, Salim, Naqib, Berlet, Peter, Pöhlmann, Klaus, Züfle, Michael

Pre-investigations on Reactive Exhaust Gas Recirculation for a Naturally Aspirated Cogeneration Gas Engine

2023-01-1212

06/26/2023

Given its ability to be combined with the three-way catalyst, the stoichiometric operation is significantly more attractive than the lean-burn process, when considering the increasingly severe NOx limit for cogeneration gas engines in Germany. However, the high temperature of the stoichiometric combustion results in increased wall heat losses, restricted combustion phasings (owing to knock tendency) and thus efficiency penalties. To lower the temperature of the stoichiometric combustion and thus improve the engine efficiency, exhaust gas recirculation (EGR) is one of the most effective means. Nevertheless, the dilution with EGR has much lower tolerance level than with excess air, which leads to a consequent drop in the thermal efficiency. In this regard, reducing the water vapor concentration in the recirculated exhaust gas and increasing the EGR reactivity are two potential measures that may extend the mixture dilution limit and result in engine efficiency benefits. Here, the reactive

Beltaifa, Youssef, Kettner, Maurice, Eilts, Peter, Ruchel, Bosse, Fröstl, Sebastian

Development of a Digital Twin to Support the Calibration of a Highly Efficient Spark Ignition Engine

2023-01-1215

06/26/2023

The role of numerical simulations in the development of innovative and sustainable powertrains is constantly growing thanks to their capabilities to significantly reduce the calibration efforts and to point out potential synergies among different technologies. In such a framework, this paper describes the development of a fully physical 1D-CFD engine model to support the calibration of the highly efficient spark ignition engine of the PHOENICE (PHev towards zerO EmissioNs & ultimate ICE efficiency) EU H2020 project. The availability of a reliable simulation platform is essential to effectively exploit the combination of the several features introduced to achieve the project target of 47% peak gross indicated efficiency, such as SwumbleTM in-cylinder charge motion, Miller cycle combined with high Compression Ratio (CR), lean mixture exploiting cooled low pressure Exhaust Gas Recirculation (EGR) and electrified turbocharging. Particular attention was paid to the definition of a

TAHTOUH, Toni, Andre, Mathieu, Millo, Federico, Rolando, Luciano, Castellano, Giuseppe, Bocchieri, Francesco, Cambriglia, Luca, Raimondo, Danilo

Use of Ferritic SS444 in Exhaust Gas Cooling for Gasoline Engine

2023-28-1328

05/25/2023

With the introduction of CAFÉ norms (Corporate Average Fuel Economy or Efficiency) in automobile industries, gasoline engines must improve their fuel economy by reducing overall CO2 footprints. To fulfil this demand many OEMs have adopted the use of exhaust gas circulation coolers (EGR) Most of the gasoline engines are having exhaust gas temperatures ranging from 650-850°C, these gases could also be highly corrosive in nature. It’s very important to select the right grade of stainless steel which should have high corrosion resistance and oxidation properties. It should also withstand high temperatures and should have low sensitization at high temperatures. Most of grades stainless steel offers high resistance against corrosion, high temperature properties. But good sensitization at high temperature is not always associated with all grades of steel. To compare corrosion resistivity, PREN number (Pitting Resistance Equivalent Number) plays important role. Highest the PREN number highest

Damle, Pankaj, Chawda, Tejesh

Turboshaft/Turboprop Gas Turbine Engine Test Cell Correlation

ARP4755C (Current)

05/19/2023

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turboprop and turboshaft engines. This Aerospace Recommended Practice (ARP) shall apply to both dynamometer and propeller based testing. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine manufacturer has their own practices relating to correlation and they will be used by those OEMS for the purpose of establishing certified test facilities

EG-1E Gas Turbine Test Facilities and Equipment

APU Gas Turbine Engine Test Cell Correlation

ARP5435A (Current)

05/19/2023

This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of APU (auxiliary power unit) engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. The baseline performance is generally determined at the original equipment manufacturer (OEM) designated test facility. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities

EG-1E Gas Turbine Test Facilities and Equipment

Turbofan and Turbojet Gas Turbine Engine Test Cell Correlation

ARP741D (Current)

05/01/2023

This SAE Aerospace Recommended Practice (ARP) describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEM’s contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities

EG-1E Gas Turbine Test Facilities and Equipment

Innovative Piston Design Performance for High Efficiency Stoichiometric Heavy Duty Natural Gas Engine

2023-01-0288

04/11/2023

Internal combustion engines will continue to be the leading power-train in the heavy-duty, on-highway sector as technologies like hydrogen, fuel cells, and electrification face challenges. Natural gas (NG) engines offer several advantages over diesel engines including near zero particle matter (PM) emissions, lower NOx emissions, lower capital and operating costs, availability of vast domestic NG resources, and lower CO2 emissions being the cleanest burning of all hydrocarbons (HC). The main limitation of this type of engine is the lower efficiency compared to diesel counterparts. Addressing the limitations (knock and misfire) for achieving diesel-like efficiencies is key to accomplishing widespread adoption, especially for the US market. With the aim to achieve high brake thermal efficiency (BTE), three (3) computational fluid dynamics (CFD) optimized pistons with three different compression ratios (CR) have been tested. Tests were carried out using a Cummins ISX-based 2.5-liter

rodriguez, Juan Felipe, Xu, Hui, Hampson, Gregory, Bestel, Diego, Windom, Bret, Olsen, Daniel

Self-Cleaning EGR Valve for Current and Future Diesel Applications

2023-01-0404

04/11/2023

In this paper, an innovative EGR valve, containing an integrated self-cleaning function to mitigate the progressive buildup of carbon deposits, is described. Conventional EGR valves use Butterfly and Poppet mechanisms to open and close a round shaped exhaust gas port with limited ability to remove exhaust carbon deposits from the affected surfaces and mechanical elements. The self-cleaning EGR valve, instead, combining both rotational and linear motions, continuously sweeps its internal passages while delivering the gas flow, removing the carbon deposits before they can adhere to the internal surfaces

Fachechi, Nicola

Laminar Burning Velocities of Diluted Stoichiometric Hydrogen/Air Mixtures

2023-01-0331

04/11/2023

Since its implementation, exhaust gas recirculation has proven to be a reliable technique to control NOx emissions by lowering combustion temperature. Dilution with exhaust gas recirculation, whether in internal combustion engines or sequential-staged gas turbine combustors, affects flame reactivity and stability, which are related to the heat release rate and engine power. Another way to control emissions is to use hydrogen as a carbon-free alternative fuel, which is considered a milestone in the energy-decarbonization journey. However, the high reactivity of hydrogen is one of its hurdles and understanding this effect on laminar burning velocity is important. Flame propagation and burning velocity control the mixture reactivity and exothermicity and are related to abnormal combustion phenomena, such as flashback and knock. Therefore, understanding the effect of exhaust gas addition on the laminar burning velocity of hydrogen/air mixtures is imperative for engine design. In this work

Barain, Ahmed, Trombley, Grace, Duva, Berk Can, Toulson, Elisa

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