Combustion Engine Research Articles

Numerical investigation on the synergistic effect of intake air temperature and hydrogen volume ratio on combustion and emissions of ammonia-enriched hydrogen spark-ignition engine

Numerical investigation on the synergistic effect of intake air temperature and hydrogen volume ratio on combustion and emissions of ammonia-enriched hydrogen spark-ignition engine

Research and evaluation of turbulent jet ignition mode for improving combustion performance of ethanol rotary engine

Improving the combustion performance of ethanol rotary engine (ERE) is crucial for enhancing energy efficiency and reducing emissions, particularly in the context of global emission reduction efforts. Although the application of ethanol as a clean alternative fuel is growing, research on optimizing its combustion in rotary engines remains limited. The novelty of this work lies in the comparison of two ignition modes: the conventional spark plug ignition mode (CSPIM) and the turbulent jet ignition mode (TJIM). Experimental validation and numerical simulation methods were employed to evaluate the effects of these two ignition modes on in-cylinder flow field and combustion characteristics. The results indicate that, compared to the CSPIM, the use of the TJIM significantly improves turbulence intensity, increases peak pressure, reduces combustion duration, and expands the flame propagation area, leading to an average increase of 0.42 kW in the power output of the ERE. Furthermore, the use of the TJIM leads to a 130 % average increase in NO mass produced in the cylinder, while CO emissions are reduced by 40 % on average. These findings demonstrate that the TJIM has significant potential to improve the combustion performance of ERE, offering considerable advantages in both efficiency and emissions control.

Comprehensive evaluation on a heat self-balanced low-temperature ammonia reforming-based high-power hybrid power generation system combined with proton exchange membrane fuel cell and internal combustion engine

Comprehensive evaluation on a heat self-balanced low-temperature ammonia reforming-based high-power hybrid power generation system combined with proton exchange membrane fuel cell and internal combustion engine

The effect of electric vehicle use on trip frequency and vehicle kilometers traveled (VKT) in the Netherlands

The transition from conventional vehicles to battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs) is expected to significantly contribute to reducing greenhouse gas emissions in the transportation sector. However, the effectiveness of this transition depends on how BEVs and PHEVs are used compared to internal combustion engine vehicles (ICEVs) and hybrid electric vehicles (HEVs). This paper analyzes data from the 2018–2020 Dutch National Travel Surveys to assess travel behavior of single-car households across four vehicle types: ICEVs, HEVs, PHEVs, and BEVs. Specifically, we focus on daily trip frequency and vehicle kilometers traveled (VKT) for both commuting and non-commuting purposes, while examining how these vehicle usage patterns correlate with vehicle attributes, socioeconomic and demographic factors, and the built environment. Our descriptive analysis shows that BEV and PHEV users have significantly longer daily VKT for both commuting and non-commuting travel compared to ICEV and HEV users. The model results reveal that after controlloing for various factors, BEVs are associated with shorter daily VKT for non-commuting travel compared to other powertrain types, while a pattern not observed for commuting travel. Notably, there is no evidence of a rebound effect linked to the use of BEV and PHEV powertrains. Additionally, leased or company vehicles, regardless of powertrain type, are associated with higher daily VKT and a higher probability of trip-making compared to privately owned vehicles. This higher daily VKT observed for BEV and PHEV users is largely due to the higher prevalence of their vehicles being leased or company cars, rather than the powertrain type itself.

Effect of different chamber geometries on combustion formation to reduce harmful emissions

The combustion process in internal combustion engines is the primary aspect of engine performance and emissions. Combustion chamber geometries such as grooved combustion chamber (GCC), shallow depth combustion chamber (SCC), and bathtub combustion chamber (BTCC) are used to investigate the effect of combustion rates on the emission parameters with respect to the standard flat combustion chamber (FCC). The impact of chamber modifications was simulated with an IC engine model using advanced chemical kinetics. Combustion parameters such as in-cylinder temperature, turbulence, and heat release rates were observed. The validated computational model assisted in analyzing combustion formations and their correlation with emissions like mass fractions, CO, CO2, and NOx. The results revealed that the modified chambers avoided the formation of fuel pockets and improved combustion behaviour compared to FCC. At 440 oCA, peak NOx emissions were higher by 14.95%, 27.10%, and 15.89% for GCC, SCC, and BTCC chambers, respectively, compared to the FCC chamber. At 440 oCA, CO2 emissions increased by 2.22%, 2.78%, and 2.78% for GCC, SCC, and BTCC chambers, respectively, compared to the FCC. The GCC chamber’s geometry influences the air–fuel mixture distribution, leading to stratified combustion zones and utilizing both bowl and squish regions. The study concludes that GCC chambers can significantly enhance efficiency and reduce emissions by influencing temperature profiles and mass fraction distributions. The study recommends using the GCC chamber with optimized injection profiles for better combustion and improved swirl rates.

Comparison between homogeneous combustion and stratified combustion caused by direct injection timing adjustment in lean-burn hydrogen internal combustion engine

Comparison between homogeneous combustion and stratified combustion caused by direct injection timing adjustment in lean-burn hydrogen internal combustion engine

Nanoparticle Counting for PTI: The Dirty Tail Paradigm — A Pragmatic Proposal to Strongly Reduce Urban PN Pollution from Combustion Engine Fleets

Using solid particle number (PN) measurements in the European Periodic Technical Inspection (PTI) of diesel engines equipped with particulate filters was proposed by VERT in 2016 during the Dieselgate Hearing of the Federal Republic of Germany. An international working group developed the standards and instruments for this method over 3 years under the leadership of TNO and VERT, which were next implemented in four countries, Belgium, the Netherlands, Germany, and Switzerland, starting in 2022. PN measurement is now state of the art, enabling rapid and reliable detection of possible failures in particulate filters and the need for their immediate restoration. This paper expands on that successful experience, recommending that PN counting be used for control of PN emissions from all vehicles during PTI. It reviews results from a number of earlier studies on “high emitters” and shows some new data sets for gasoline engines. Five large vehicle fleets, diesel and gasoline, heavy-duty engines (HDE), light-duty vehicles (LDV), and non-road mobile machinery (NRMM), with and without emission aftertreatment were analyzed. It was observed that, while most vehicles in working fleets are clean (i.e., meet or often are far are below their corresponding emission limits), every fleet, however, contains some high emitters, about 4–8% of the fleet hereby termed “dirty tail” — diesel as well as gasoline engines. This small fraction dominates the PN emission of the entire fleet and may increase the overall PN emission of its corresponding fleet by more than tenfold over the level of the compliant vehicles! Experience indicates that PN emission may be a strong indicator of many different deteriorations in a combustion engine and thus can be used as a highly sensitive diagnostic signal to detect various engine or emission faults quickly and reliably. This is a new understanding of emission control of vehicle fleets: not by regulations for new vehicles only which apply for all vehicles but by selecting the high emitters and consequently repair or replace these relatively few vehicles to the extent desired in terms of emissions policy. Most countries have already implemented strong periodic technical inspection systems. We suggest to expand such tests by additionally measuring the particle number concentration in the exhaust gas of all vehicles for just 1 min, thereby detecting the high emitters. With consistent annual monitoring, this procedure will reduce urban particle pollution from combustion engines to one-tenth or lower, a significant contribution to reducing local health risks.

Evaluation of auditory alerting systems for safe electric scooter operations

It is well understood that a significant shift away from fossil fuel based transportation is necessary to limit the impacts of the climate crisis. Electric micromobility modes, such as electric scooters and electric bikes, have the potential to offer a lower-emission alternative to journeys made with internal combustion engine vehicles, and such modes of transport are becoming increasingly commonplace on our streets. Although offering advantages such as reduced air pollution and greater personal mobility, the widespread approval and uptake of electric micromobility is not without its challenges. Concerns have been raised regarding the safety of such vehicles, most notably related to pedestrian safety of blind and partially sighted individuals, due to the inherently lower sound levels produced by electric vehicles. This study addresses this issue by investigating the use of an Acoustic Vehicle Alerting System (AVAS) for electric scooters by means of a virtual reality experiment and field trials. Eighty-eight participants from four European countries, including thirty-five blind or partially sighted individuals participated across the experiments. Results show high missed detection rates for electric scooter operations without an AVAS in typical city soundscapes (90–97%) and an increase in detectability for all AVAS conditions tested. Modifying AVAS sounds with playback rate and level changes with respect to operational state facilitates detection of deceleration, as well as improving detectability in multiple vehicle scenarios.

Development of Hybrid Vehicle

Model-Based Design can be applied in the development of a hybrid electric vehicle system. The paper explains how Model-Based Design begins with defining the design requirements that can be traced throughout the development process. This leads to the development of component models of the physical system, such as the power distribution system and mechanical drive line. We also show the development of an energy management strategy for several modes of operation including the full electric, hybrid, and combustion engine modes

The closing longevity gap between battery electric vehicles and internal combustion vehicles in Great Britain

Abstract Electric vehicles are increasingly being adopted in Great Britain and other parts of the world, driven by the perception that they offer a cost-effective alternative to internal combustion engine vehicles while reducing emissions. However, a key element that underpins this perception is the longevity of electric vehicles, which remains relatively under researched. Here we show that although early battery electric vehicles (BEVs) exhibited lower reliability than internal combustion engine vehicles, rapid technological advancements have allowed newer BEVs to achieve comparable lifespans, even under more intensive use. Longevity is also found to be impacted by engine size, location and make of vehicle. We provide parameter estimates for life mileage that can be used to update life cycle assessment and total cost of ownership studies of different vehicle powertrains. Our results also shed light on BEV diffusion patterns, fleet replacement strategies and end-of-life treatment planning, including the increasingly important debate around BEV battery recycling and second-life options.

Investigating The Combustion Performance of Dual Fuel Combustion With Diesel and Port Injected Hydrogen In A Large Bore Locomotive Engine

Abstract The heavy-duty transportation sector has primarily relied on conventional diesel combustion engines given their reliability and high thermal efficiency relative to spark ignition engines, but increased focus on reducing greenhouse gas emissions has led to investigation into alternative fuels. Gaseous hydrogen fuel has garnered a great deal of recent interest in the engine community given it has zero carbon, but hydrogen is not available at the scale and cost that petroleum fuels are currently available, and this is a barrier to adoption for industries that are looking to decarbonize their operations. Because of the fuel flexibility provided, dual fuel technology offers a pathway for some industries to adopt hydrogen as a fuel source while maintaining sufficient flexibility in times and locations where the new fuel is not yet available. This computational study investigates dual fuel combustion in a large bore locomotive engine architecture using direct injected diesel and port injected gaseous hydrogen fuel. With an optimal port fuel injection configuration from previous work [18], simulations of varying substitution ratio, compression ratio, intake manifold air temperature, diesel injection timing, and diesel injection pressure were performed to understand their effect on combustion performance. Results indicated that both increased substitution ratio and higher intake air temperature accelerates hydrogen flame propagation and can result in high peak cylinder pressures. Additionally, diesel injection timing and injection pressure were demonstrated as effective methods for controlling dual fuel combustion heat release rates.

Restrict Toxic Emissions from Internal Combustion Engines to Protect the Environment by Using Diesel Fuel Mixed with Vegetable Oil

For internal combustion engines, engines installed for transport ships, cargo ships, and fishing vessels are mainly diesel engines. The number of engines is increasing due to the development of the maritime and seafood exploitation sectors. Therefore, the high demand for petroleum fuels increases environmental pollution due to engine emissions. Reducing environmental pollution from the combustion of petroleum fuels has become a concern worldwide, especially for internal combustion engines. The exhaust gases from the engine contain harmful substances such as soot and nitrogen oxides (NOx). Fuels with higher carbon content generate more soot when burned. In contrast, biofuels have low carbon and sulfur content and supply ample oxygen, which helps to reduce soot formation. For these reasons, biofuels are encouraged as alternative fuels to petroleum. Vegetable oil is one of the primary raw materials for biofuel production. This study presents a mixture of diesel and vegetable oil utilized as fuel for fishing vessels’ diesel engines. The results of experimental research on a fishing vessel’s 4CHE Yanmar diesel engine when using diesel fuel mixed with coconut oil (B15, 15% coconut oil, and 85% diesel) show that increasing B15 fuel injection pressure by about 10–15% compared with diesel fuel injection pressure reduces the engine’s soot emissions and increases power compared to unadjusted. This solution contributes to reducing environmental pollution from engine emissions.

Effects of EGR Rate and Temperature on Combustion and Emissions Characteristics of Compression Ignition Engines Fueled with Hydrotreated Vegetable Oil.

This study investigates the effects of varying exhaust gas recirculation (EGR) rates and temperatures on the combustion and emissions characteristics of a compression ignition engine fueled with hydrotreated vegetable oil (HVO). Understanding these effects is essential for optimizing renewable fuel applications in compression ignition engines, contributing to cleaner combustion, and supporting sustainable transportation initiatives. The experiments revealed that increasing the EGR rate to 20% not only reduces NOx emissions by approximately 25% but also increases smoke by around 15%, highlighting a trade-off between NOx and particulate matter control. When EGR temperature is increased from 130 to 220 °C, NOx emissions rise by about 10%, accompanied by a 12% increase in smoke emissions, indicating that elevated EGR temperatures can counteract the NOx-reducing benefits of EGR by raising the overall combustion temperature. Additionally, a higher EGR rate shifts particle size distributions, reducing nucleation mode particles by about 30% while increasing accumulation mode particles, with peak concentrations moving toward larger diameters. These findings suggest that precise control of EGR parameters is essential for optimizing emissions performance and ensuring the feasibility of HVO as an alternative fuel in compression ignition engines.

Developing an Algorithm Limiting the Longitudinal Acceleration of an Electric Vehicle

The electric traction drive is increasingly being applied as a device providing traction force on driving wheels. This is due to its reliable torque transmission to the driving wheels, step-less regulation of the traction force on the driving wheels depending on the driving conditions, and increased design capabilities. In terms of power, the electric traction drive has maximum torque at low speeds, which internal combustion engines lack. This property of the electric drive is not applied in urban vehicles, as not all passengers are comfortable with intensive acceleration. In modern vehicles with an electric traction drive, the maximum acceleration can be limited by software, which is the focus of this study. This paper aims to develop an algorithm capable of recognizing when the permissible longitudinal acceleration exceeds the limit and generating an action to maintain the acceptable acceleration level. The electric traction drive of a large-class electric bus was used as a control object. An algorithm and a control law are hereby developed, which reduce longitudinal acceleration using PI control. Both simulation modeling and full-scale tests on the electric bus were carried out to evaluate the performance and efficiency of the algorithm. In this paper, the authors also introduce the cumulative velocity concept and prove the operability and efficiency of the developed method.

Fuelling Electric Vehicles Growth: Factors that Matter in India’s Electric Vehicles Growth Story

The recent impetus to the electric vehicle (EV) policies at the national and sub-national levels with the medium to long-term objective of reducing greenhouse gas emissions from vehicle traffic motivates an assessment of the key drivers of EVs in India. The sale of EVs especially two-wheelers is rising due to the push by government policies, reduction in upfront costs and increased awareness about EVs. However, the sale of electric cars has not picked up significantly and is uneven across states. The study finds a strong correlation between the use of electric cars in states and the availability of public charging stations. The empirical analysis finds that the availability of public charging infrastructure and the price differentials between electric cars and comparable internal combustion engine cars are significantly associated with the demand for cars across states. A focused and liberal policy assumes importance to stimulate the demand for EVs and to harness its manifold environmental and financial gains. JEL Classifications: Q42, Q48, Q49

Key Technologies to 50% Brake Thermal Efficiency for Gasoline Engine of Passenger Car

Review Key Technologies to 50% Brake Thermal Efficiency for Gasoline Engine of Passenger Car Xinke Miao, Bingxin Xu, Jun Deng, and Liguang Li * School of Automotive Studies, Tongji University, Shanghai 201804, China * Correspondence: liguang@tongji.edu.cn Received: 13 August 2024; Revised: 6 December 2024; Accepted: 17 December 2024; Published: 20 January 2025 Abstract: As fuel consumption and emissions regulations become increasingly stringent, various advanced strategies have been proposed to achieve higher efficiency in internal combustion engines. This paper reviews the advancements in thermal efficiency of gasoline engines and analyzes the key technological methods to achieve over 50% brake thermal efficiency (BTE). The technological routes proposed for high-efficiency gasoline engine are primarily focused on high compression ratios and lean combustion combined with novel combustion technologies. Supporting technologies mainly include Atkinson/Miller cycles, intake boosting, exhaust gas re-circulation (EGR), water injection, thermal barrier coatings, friction reduction, structural optimization, and combustion diagnostics and control.

Performance and emissions of diesel engine combustion lubricated with Jatropha bio-lubricant and MWCNT additive

Vegetable oil-based lubricants, modified through transesterification and epoxidation, present a sustainable alternative to mineral lubricants for transport and industrial use. This study evaluates epoxidized jatropha oil (EJA) enhanced with multi-walled carbon nanotubes (MWCNT) as a bio-lubricant for compression ignition engines. MWCNT, dispersed in EJA using an ultrasonic probe sonicator with Triton X-100 as a surfactant, was tested at nanoparticle concentrations from 0.5 to 2 wt%. Engine performance and emission characteristics were assessed using SAE 20W40, EJA, and EJA-MWCNT in a four-stroke diesel engine. Results showed that EJA with 2 wt% MWCNT reduced friction power by 39.13% compared to SAE 20W40 and decreased brake specific energy consumption by 6.11%, while lowering emissions of hydrocarbons, carbon monoxide, and smoke. These findings highlight EJA-MWCNT as a promising lubricant for diesel engines, enhancing efficiency and reducing pollutants, making it a viable eco-friendly substitute for diminishing petroleum resources.

Effects of Two-Stage Injection on Combustion and Particulate Emissions of a Direct Injection Spark-Ignition Engine Fueled with Methanol–Gasoline Blends

Effects of Two-Stage Injection on Combustion and Particulate Emissions of a Direct Injection Spark-Ignition Engine Fueled with Methanol–Gasoline Blends

Flame–Flame Interactions and Jet–Jet Interactions in Gas Turbine Swirl Combustors

Annular combustors are widely used in newly developed aero-engines. Nevertheless, the development of annular combustors requires substantial air supplies and high-power heaters during testing, leading to high experimental costs. To reduce these costs during the design phase, researchers often simplify annular combustors into single-dome configurations using aerodynamic and thermodynamic similarity principles. A fundamental divergence exists between the boundary conditions of annular and simplified single-dome combustors, which is reviewed in this article. It highlights the limitations of single-dome model combustors in accurately representing the crucial features of annular combustors, particularly flame–flame interaction (FFI) and jet–jet interaction (JJI). FFI and JJI existing in annular combustors are observed to result in alternating flow patterns and the superposition of mass and energy transfer between adjacent domes, which can deteriorate flame stabilization and increase NOx emissions. This review emphasizes the characteristics of multi-dome combustors and notes a lack of research comparing single-dome and multi-dome combustors under engine-relevant conditions. Addressing this research gap in the future can better connect fundamental combustion research and engine development, providing more guidance for engine designers.

Life Cycle Economic and Environmental Assessment for Emerging Heavy-Duty Truck Powertrain Technologies in China: A Comparative Study of Battery Electric, Fuel Cell Electric, and Hydrogen Combustion Engine Trucks.

Amid ambitious net-zero goals and growing demands for freight logistics, addressing the climate challenges posed by the heavy-duty truck (HDT) sector is an urgent and pivotal task. This study develops an integrated HDT model by incorporating vehicle dynamic simulation and life cycle analysis to quantify energy consumption, greenhouse gas (GHG) emissions, and total cost of ownership associated with three emerging powertrain technologies in various truck use scenarios in China, including battery electric, fuel cell electric, and hydrogen combustion engine trucks. The results reveal varying levels of economic suitability for these powertrain alternatives depending on required driving ranges and duty cycles: the battery electric for regional-haul applications, the hydrogen fuel cell for longer-haul and low-load driving conditions, and the hydrogen combustion engine to meet high power requirements. The GHG mitigation potential of these technologies, on the other hand, critically hinges on energy sources. All three powertrains could achieve over 55% GHG emission reductions if the power sector and hydrogen supply are substantially decarbonized by 2035. The analysis underscores the necessity for a broad policy approach on a life cycle basis to incorporate all powertrain technologies and all energy sources in a complementary manner for facilitating a low-carbon road freight future.