Browse Topic: Internal combustion engines

Items (19,678)
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Chen, KeYang, ChenxiWang, YibinFan, JinyuLiu, YuchenYe, ZixiaoHuang, Jialiang
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Liu, YuchenYang, ChenxiFan, JinyuChen, KeYe, ZixiaoHuang, Jialiang
Diesel engines used for the main power supplier of submarine normally run in high back pressure and low intake pressure, causing unstable performances. Furthermore, when a submarine runs under the sea the exhaust pipe of the diesel engine is under the seawater. Once the lowest pressure in the exhaust pipe is not sufficient to push all the water out, the water will flow into the exhaust pipe and damage the diesel engine. Modeling can provide a useful guide for designing diesel engines, intake and exhaust pipes, and turbocharging systems to avoid water flowing into diesel engine. However, existing simulation methods cannot well simulate the exhaust system of an underwater diesel engine, in which the interface between the liquid water and the exhaust gas is variable. To overcome the drawbacks of existing simulation methods in handling the variable interface between the two phases, a variable interface finite volume method (FVM) is proposed, and a corresponding model is developed in this
Guo, DongshaoZhang, LichengYang, ShiyouSun, YongAbidin, ZainalLin, Shujun
This research examined the performance of SAE Level 2 (L2) advanced driver assistance systems (ADAS) in crash-imminent scenarios (CIS), with particular attention to how vehicle configuration like body style and powertrain (internal combustion engine, plug-in hybrid, electric vehicle) influences vehicle system performance. The objectives were to (1) identify CIS relevant to L2-equipped vehicles using crash databases and naturalistic driving studies (NDSs), (2) develop scenario-based test procedures and test matrices, and (3) evaluate system and vehicle responses across configurations and conditions. Multiple crash data sources were analyzed, including NHTSA’s Standing General Order dataset of L2-related crashes, the Fatality Analysis Reporting System, the Crash Report Sampling System, and NDS data from the Second Strategic Highway Research Program and the Virginia Tech Transportation Institute L2 NDS. Coded variable analyses from the datasets identified three common CIS: lane and road
Beale, GregoryKefauver, KevinVenegas, MichaelLi, EricChen, JayHuggins, StevenGuduri, BalachandarLlaneras, Eddy
TOC
Tobolski, Sue
Stochastic end-gas autoignition in spark ignition (SI) engines, commonly called “knock,” limits attainable engine efficiencies. Multiple pathways to extend SI engine operation into knock-limited regions have been studied, including direct water injection (DWI). This study employs single-cylinder engine experiments with a centrally mounted water injector to investigate the knock resistance offered by compression stroke water injections, which, through incomplete mixing, can thermally stratify the cylinder. In SI, thermally stratifying injections are expected to forcibly widen the cylinder temperature distribution by preferentially cooling the cylinder periphery. The end-gas is in the cylinder periphery. A cooler end-gas would result in longer ignition delays, thus providing knock resistance. The difference between intake temperature required to match knock-limited CA50 and a baseline intake temperature at the load of 8 bar IMEPg (gross indicated mean effective pressure) was used to
Datar, AdityaVedpathak, KunalGainey, BrianLawler , Benjamin
Vehicle pollutant emissions are a major challenge in the development of internal combustion engines. To meet increasingly strict regulations, the automotive sector is exploring alternative fuels and lean-burn strategies. Methanol is gaining importance as a carbon-neutral fuel due to advances in green production technologies. Methanol, despite its potential for renewable production, faces severe limitations due to its inherent poor cold-start performance with conventional ignition systems. In this context, the present study aims to investigate the influence of pre-chamber ignition on cold-start combustion by using high-speed optical diagnostics to visualize flame propagation while simultaneously measuring in-cylinder pressure and engine performance. A major result concerns the significant cyclic variability of conventional spark ignition (SI) under cold-start conditions, which exhibits significant cyclic variability. Instead, passive pre-chamber ignition significantly enhances cold
Sementa, PaoloAltieri, NunzioTornatore, Cinzia
Agriculture sector is undergoing a phenomenal transformation, driven by the legislative requirements mandated by countries worldwide to tackle global warming through stringent global emission and on the need to improve operator safety, productivity, particularly on sloped and uneven terrains. Conventional tractors with internal combustion engines (ICEs) have been in use for decades but they often have issues over coordinated control on inclined terrains, especially during load transitions, start-stops, and loader operations. Due to which operators have a critical task of maintaining vehicle stability, controlling rollback on gradients — leading to compromised efficiency, safety risks, and increased fatigue. Global Emission Norms are getting stringent and the justification to end user on the Incremental value proposition is getting difficult to make the products appealing. To address these multifaceted challenges, this paper presents the architecture and functional strategy to increase
M, RojerNatarajan, SaravananMuniappan, Balakrishnan
Towing imposes substantial efficiency penalties on both battery-electric vehicles (BEVs) and internal combustion engine (ICE) vehicles, reducing range by 30-50%. This paper presents a proof-of-concept embedded control architecture for distributed trailer propulsion that actively regulates drawbar force to reduce towing loads. Unlike proprietary e-trailer systems requiring specialized hardware, the proposed implementation demonstrates feasibility using commercial off-the-shelf (COTS) components and open-source software. The distributed architecture employs dual Raspberry Pi 4B single-board computers communicating via ROS 2 at 20 Hz. The trailer-mounted controller executes a Simulink-generated control node coordinating load cell acquisition (HX711 ADC), motor CAN bus telemetry, and throttle commands to a 5 kW BLDC traction motor powered by a 5 kWh LiFePO4 battery pack. A vehicle-mounted controller logs OBD-II/CAN validation data. The control pipeline implements cascaded EWMA/Hampel
Joshi, GauravAdelman, IanLiu, JunDonnaway, Ruthie
The search for alternative solutions for non-fossil fuels has led to several studies worldwide. This study focuses on environmentally responsible solutions to accelerate tire degradation, focusing on the transformation of these residues into fuel for diesel engines. The objective of this study was to experimentally evaluate, through numerical simulation, the performance of a compression ignition engine operating with pure diesel S10 fuel, crude and refined tire pyrolytic oil, and mixtures in proportions of 20, 40, 60, 80 and 100% with diesel oil. The experimental tests were performed on a single-cylinder engine coupled to a dynamometer bench, and the numerical simulation was performed using the Diesel Engine RK software. The experimental results indicated that increasing the proportion of refined pyrolytic oil in diesel slightly improves engine performance up to approximately 2750 RPM, after which the performance is reduced compared to pure Diesel. The addition of crude pyrolytic oil
Santana, Claudio MarcioPrudente, Lucas RhuanLeal, Elisangela MRocha, Ana MauraPeixoto, Claudio
This study experimentally investigates the combined effects of exhaust gas recirculation (EGR) and injection timing on the combustion and emission characteristics of a hydrogen direct injection engine. A single-cylinder 395 cc research engine was used, with injection timing varied from 60° to 180° BTDC and EGR rates from 0% to 30%. In-cylinder pressure, apparent heat release rate (AHRR), NOx, and unburned hydrogen concentrations were measured to analyze the influence of mixture formation and dilution on engine performance. Under non-EGR conditions, retarding the injection timing promoted mixture stratification, resulting in faster flame propagation and shorter combustion duration. However, localized high-temperature regions increased NOx formation, while incomplete combustion in lean or rich zones elevated unburned hydrogen emissions. When EGR was introduced, both ignition delay and combustion duration increased due to reduced oxygen concentration and thermal dilution. Nevertheless
Yang, HeetaeKi, YoungminKim, Jungho JustinKim, JinsuBae, ChoongsikHwang, Joonsik
Achieving the stringent EPA CAFE 2032 standards for light-duty full-size trucks and sport-utility vehicles (SUVs) in North American poses significant challenges. While Battery Electric Vehicles (BEVs) offer a clear path to zero tailpipe emissions, their widespread adoption in this segment faces hurdles including range anxiety, payload/towing capabilities, and traditional truck/SUV use cases. This paper investigates a balanced approach, focusing on optimizing propulsion system design with appropriate hardware content, can effectively meet future fuel economy and emissions standards. This investigation examines advanced BEVs and hybrid electric vehicle architectures, including full hybrids (HEVs), and plug-in hybrids (PHEVs) tailored for full-size trucks and SUVs. Considerations include the optimal sizing of internal combustion engines, electric motors, and battery packs to deliver robust performance while maximizing energy efficiency. This paper analyzes the integration of technologies
Babcock, DillonRobinette, Darrell
Off-road vehicles are typically powered by diesel engines, sized to cover the highest peak loads in their dutycycles. Such applications can be designed with downsized engines, using hybridization to supplement engine power with electrical power for short periods. However, many applications are low-volume and specialized, making it impractical to deploy heavy engineering resources to optimize each one. For this reason, manufacturers tend to produce maid-of-all-work vehicles to cover every situation. This paper demonstrates the benefits of custom hybridization for specialist applications, and addresses the lack of accessible software tools for evaluating such opportunities. Analysis is applied with a fast, low-cost, Concept-based software tool named “ePOP Concept”, suited to original equipment manufacturers (OEMs) who seek to provide custom low-volume vehicles. It allows many different powertrain architectures to be evaluated rapidly at the product planning stage, and can be quickly set
De Salis, RupertFons, Daniel
Diesel particulate filters (DPF) have been part of vehicle after-treatment solutions in the US since being adopted in 2007 as the “go-to” solution for meeting particulate mass (PM) standards as set by the EPA for HD diesel engines. Within the highly popular LD/MD truck segment, defined as trucks weighing between 8501lb-14000lb, these limits have seen additional reduction in PM levels to 8 or 10 mg/mile as these vehicles have transitioned mostly over to chassis-based certification since 2014-2017. However, these reductions in PM requirements have been relatively minor, allowing for DPF technology used on these platforms to remain mostly unchanged over the same time period. With the finalization of MY27+ LD/MD vehicle emissions standards; PM limits are now set to make significant reductions down to 0.5 mg/mile, with phase-in to be completed by MY31. While the new limits present significant challenges for gasoline vehicles and most likely will require the use of gasoline particulate
Warkins, JasonSadek, GhadiHe, Suhao
Spark plug durability is a factor affecting the total cost of ownership (TCO) of spark-ignited natural gas engines, with some heavy-duty platforms requiring plug replacement after only 750 hours of operation. The high ignition energy demand under lean or diluted conditions accelerates electrode wear, shortening plug life and increasing maintenance frequency. This work evaluates passive pre-chamber (PC) ignition operating at lowered spark energies as a strategy to reduce spark energy requirements and extend plug durability, thereby lowering TCO. Experiments were conducted on a medium-duty Cummins 6.7L ISB engine at 1600 RPM and 50% load under varying exhaust gas recirculation (EGR) dilution levels (0–40%). Two passive pre-chambers with 1.1 mm and 1.6 mm nozzle diameters were compared with conventional spark ignition (SI). SI was operated with a fixed coil dwell of 4 ms (~90 mJ), while the PC configuration was tested across 2–4 ms dwell times (~30–90 mJ). Cylinder pressure analysis
Dhotre, AkashVoris, AlexOkey, NathanKane, SeamusRajasegar, RajavasanthNorthrop, William
Hydrogen Internal Combustion Engines (H₂ICEs) offer the potential for near-zero carbon emissions. However, while nitrogen oxide (NOₓ) emissions have been extensively studied, particulate emissions, specifically particle number (PN), which are widely attributed to in the literature to lubricant oil pyrolysis and exacerbated by hydrogen’s short quenching distance, remain less well understood. This study investigates exhaust-gas particle emission characteristics from a spark-ignition, single-cylinder research engine based on MAHLE Powertrain’s downsizing engine combustion system. The work was carried out at Brunel University of London and compares gasoline and hydrogen direct-injection strategies (central versus side injection) across a wide range of operating conditions, including variations in engine speed, load, air–fuel ratio (λ), rail pressure, and spark timing. While previous studies have investigated hydrogen particle formation mechanisms under isolated operating conditions, the
Harrington, AnthonyZaman, ZayneNickolaus, ChrisZhao, HuaWang, XinyanHall, Jonathan
As internal combustion engines continue to play a critical role in hybrid on-road and numerous non-road applications, there is a continued push to increase efficiency and minimize tailpipe emissions. However, reduced investment in new engine architectures means retrofittable technologies are favored to continue incremental performance improvements to existing engine platforms. To maintain the relatively low capital cost of engine-based powertrains, these technologies must be low-cost and compatible with the diverse mix of fuels that may be encountered across various market segments in the future. Pre-chambers have shown significant potential for improving spark-ignited engine performance across a wide range of engine sizes, from motorsport applications to stationary power, and operating conditions, from stoichiometric operation to ultra-lean. Understanding the degree to which this central combustion technology must be tailored to optimize its performance with a variety of fuels and
Peters, NathanPothuraju Subramanyam, SaiHoth, AlexanderBunce, Michael
This study investigates the impact of the hydrogen split injection ratio on the combustion of pilot diesel-ignited hydrogen direct-injection engines, which is expected to affect hydrogen-air mixture conditions and thus flame propagation and diffusion flame developments. Experiments were conducted on a 1-litre single-cylinder diesel engine equipped with an additional hydrogen injector operating at 35 MPa. Hydrogen accounting for 95% of total input energy was injected at 150 and 60 °CA bTDC for the first and second pulses, which were selected as high-efficiency injection timings from previous equal-split injection tests. The 5% diesel energy was injected near TDC to control CA50 at 10 °CA aTDC. While varying the split ratio between the two hydrogen injections, in-cylinder pressure/aHRR profiles, engine efficiency/power output and engine-out emissions of NOx and CO2 were evaluated. Results showed that the hydrogen split ratio does not significantly affect IMEP/efficiency, which
Zhao, YifanChan, Qing NianKook, Sanghoon
Compared to regular fuels, biofuels can play a key role as low-carbon transitional energy sources for ICE vehicles as the fleet moves towards increasing electrification. Blending of ethanol plays a key role in enhancing the anti-knock properties of the fuel and also allows renewable hydrocarbons (such as bio-naphtha) to be incorporated into the blend whilst maintaining an acceptable overall fuel quality. Super lean burn ICE technology with λ between 2 and 3 can lead to enhanced fuel economy and reduced NOx emissions. The Toyota prototype engine used to generate data for this project injects most of the fuel in PFI mode to generate a homogeneous super-lean charge in the cylinder, but just before spark ignition the DI injector sprays a small amount of fuel towards the spark plug to create a richer charge near the spark plug to promote flame kernel development. Various fuel formulations with high biofuel content were tested in both conventional and super lean burn engines. Certain fuel
Aradi, AllenKrueger-Venus, JensJain, Sandeep KumarCracknell, RogerKolbeck, AndreasShibuya, MasahikoYamada, RyotaMatsubara, NaoyoshiKitano, Koji
The growing demand for sustainable mobility and transportation is accelerating the adoption of alternative fuels, particularly hydrogen, in internal combustion engines. The first part of this publication series highlights the significance of 2D simulation as a crucial and computationally efficient tool for the precise development of hydrogen Power Cylinder Units. This approach demonstrates predictive capability proofed through engine tests, achieving a reduction in lube oil consumption by 5 g/h during high-load operations, alongside a 28% decrease in blow-by and an 11% reduction in hydrogen flow to the crankcase. To provide deeper insights into the complexities identified in Part 1, this study employs inter-ring pressure measurements across various engine types and configurations, including light vehicles, heavy-duty trucks, and large-bore applications, covering a broad range of engine displacements from 2 to almost 100 liters. This investigation in Part 2.1 focuses on understanding
Moreira, RuiKöser, PhilippRösch, HannesEhnis, Holger
The use of hydrogen in internal combustion engines offers a promising route to lower-carbon propulsion in heavy-duty transportation. However, its distinct combustion characteristics as high flame speed, wide flammability limits, and susceptibility to abnormal combustion, necessitate careful engine and ignition system design. This study numerically investigates the combined effects of spark plug (SP) location and ignition timing on the performance of a heavy-duty diesel engine converted to spark-ignition and operated with hydrogen as fuel at reduced compression ratio. The numerical study aims to guide engine design. Three-dimensional computational fluid dynamics simulations with detailed hydrogen chemistry were conducted to evaluate flame development, and relevant combustion metrics under different loads. Model validation against engine combustion data and hydrogen injection from a low-pressure, high-mass-flow direct injector are also presented. The results demonstrate that SP placement
Menaca, RafaelShakeel, Mohammad RaghibPanithasan, MebinLiu, XinleiQahtani, YasserAlRamadan, AbdullahCenker, EmreSilva, MickaelPei, YuanjiangTurner, JamesIm, Hong
The utilization of gasoline engines in heavy-duty vehicles for the purpose of continental transportation is in direct competition with conventional diesel engines. It’s imperative that the operating performance of the gasoline engine is equivalent to the diesel engine, and that the gasoline engine shows efficiency benefit to both cost segments, the product manufacturing costs and total cost of ownership (TCO). The 11.6-liter gasoline engine developed has been designed and applicated in such a way that it operates at a stoichiometric combustion air ratio (λ = 1) across the entire engine map range without exception. In combination with external exhaust gas recirculation (EGR) this strategy does not result in a substantial decrease in the absolute NOx concentration in raw emissions compared to the diesel engine with 15.0-liter displacement, but it facilitates the cost-efficient utilization of the three-way catalyzer as the main exhaust aftertreatment system, thereby reducing NOx emissions
Medicke, MarioArnold, ThomasBohme, JanKrause, MatthiasLeesch, Mirko
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