Browse Topic: Combustion and combustion processes

Items (15,300)
Despite the increasing electrification of current vehicles, Diesel engines will continue to be used for several decades to come. There is still a need to introduce emission control technologies, especially those that show good potential and do not require extensive engine modifications. The increasing focus on reducing pollutant emissions and improving energy efficiency has prompted engine manufacturers to continuously strive for technological progress. The aim is to ensure compliance with environmental regulations and the fulfillment of social expectations. Specifically, new Diesel engine projects face the challenge of minimizing both nitrogen oxides (NOx) and soot emissions, which requires significant investiment in research to develop innovative combustion methods and exhaust gas treatment. One of these innovative methods is Ducted Fuel Injection (DFI), which aims to reduce emissions by improving spray development to obtain a better mixture at flame upstream. This study presents an
Dias, Fábio Jairodos Santos, Leila RibeiroRufino, CaioGarcia, Ezio CastejonLomonaco, RaphaelArgachoy, CelsoLacava, Pedro Teixeira
The Brazilian government encourages the use of renewable fuels in diesel engines through resolutions that define the mandatory addition of biodiesel to automotive diesel oil. The use of biodiesel will reach 15% by 2026. Due to this change in the physicochemical characteristics of commercial fuel, there is a need to deepen studies regarding the combustion process and the effects of this change on engine performance and emissions. With technological advancements, one of the viable techniques for this purpose is high-speed imaging to assess combustion within the cylinder. This paper presents the methodology for constructing a system that allows high-speed imaging, using a high-speed camera, of the combustion process of an MWM 229/4 engine. Other studies published in this area typically involve capturing images inside the cylinder once per cycle and advancing the angular position of capture each cycle. This paper proposes a more refined method, where images are acquired every 2.5°CA
Ferreira, Bruno Eustáquio PiresMoreira, Vinícius GuerraBorges, Débora Maria de O.Morais Hanriot, Sérgio
The increasing impacts of the greenhouse effect have driven the need to reduce pollutant emissions from internal combustion engines. Renewable fuels are promising alternatives for emission reduction, and enhancing engine efficiency can further decrease specific emissions. This study explores the development of dual-fuel engines to meet these goals, focusing on dual-fuel combustion in spark-ignition (SI) engines using two different bioethanol and natural gas mixtures. A novel methodology for 1-D predictive combustion simulation in dual-fuel SI engines was developed and implemented in GT-Suite software. The approach involves a straightforward estimation of the laminar flame speed of the fuel mixture and the calibration of turbulent combustion parameters using a genetic optimization algorithm, without the need for complex chemical kinetics models. The results indicate that the proposed methodology can reproduce combustion characteristics, achieving satisfactory outcomes across most tested
Pasa, Giovanni DuarteMartins, ClarissaCota, FilipeDornelles, HenriqueDuarte, ThalesRosalen, RodrigoPujatti, Fabrício José Pacheco
In the global scenario marked by the increasing environmental awareness and the necessity on reducing pollutant emission to achieve the decarbonization goals, action plans are being proposed by policy makers to reduce the impact of the climate change, mainly affecting the sectors that most contribute to CO2 emissions such as transportation and power generation. In this sense, by virtue of the National Energy Plan 2050, the Brazilian market will undergo the decommissioning of thermal power plants fueled by diesel and heavy fuel oil (HFO) by 2030, compromising about 6.7 GW of power capacity according to the Brazilian Electricity Regulatory Agency (ANEEL) database. An alternative to the scrapping of these engine power plants is their conversion to operate with fuels with a lower carbon footprint, such as the natural gas. This work, therefore, aims to numerically assess the conversion feasibility of a HFO large bore four-stroke turbocharged engine to operate with natural gas by means of a
Gonçalves, Vinícius FernandezZabeu, Clayton BarcelosAntolini, JácsonSalvador, RobertoAlmeida, RogérioValiati, Allan SoaresFilho, Guenther Carlos Krieger
Hybrid Electric Vehicles (HEVs) combine combustion and electric propulsion means to achieve key objectives, such as: reducing fuel consumption, minimizing pollutant emissions, and enhancing the overall energy efficiency of the Powertrain System. The series hybrid electric vehicles, in special, have a topology compound by four Subsystems, which are: Traction, Storage, Energy Generation, and Energy Management. The Energy Generation Subsystem is responsible for the power supply of the electric traction motors and batteries, depending on the control strategy promoted by the Energy Management Subsystem. The Energy Generation Subsystem is essentially made by an Internal Combustion Engine (ICE) and a Generator. Effective control of the power output from the Energy Generation Subsystem necessitates precise regulation of the engine speed. Thus, it is necessary to control the engine speed because this is directly related to the power demand of the consumers of other subsystem components. This
Júnior, João Marcos Hilário Barcelosde Sousa Oliveira, Alessandro BorgesTeixeira, Evandro Leonardo SilvaPereira, Bruno LuizPinheiro, Leandro Soaresdos Santos Ribeiro, Eduardodos Santos de Oliveira, Jordano
In recent years, the use of ethanol fuel in internal combustion engines has gained importance due to environmental and commercial factors, since ethanol produces lower emission rates at similar performance parameters compared to gasoline fuel. The objective of this study is to evaluate and compare the effects of engine performance parameters on the vibration level of the engine block operated with gasoline and ethanol fuel. The experimental tests consisted of operating an Otto cycle engine on a bench dynamometer under full load conditions varying rotation and correlating the vertical, longitudinal and transverse vibration levels of the block engine with the engine performance parameters. The results showed that the engine vibration level was influenced by engine speed, load, type of fuel and performance parameters of the engine. The combustion process is primarily responsible for the highest level of vibration reached when using ethanol as a fuel. Under all operating conditions, the
Santana, Claudio MarcioSantana, Linicker Lopes BrunoAlmeida, Helder Giostri Alves
Given the recent increase in exhaust gas emission restrictions, electrification has become the major development focus in the transportation industry. Like combustion vehicles, electrified ones must also undergo homologation tests. According to the Battery Electric Vehicle (BEV) homologation standard, SAE J1634, the vehicle must be subjected to a minimum 1600 km break-in cycle. This standard also allows the battery to undergo an equivalent cycle that results in the same level of degradation. Since the recommended break-in cycle duration exceeds the vehicle’s battery autonomy, at least one recharge is necessary to accomplish the break-in normalization. This requirement implies more time allocated to a dynamometer, which represents additional costs to the manufacturer. As in any industry, cost reduction is crucial to enable the development of new technologies in the automotive industry. To contribute to this, a faster battery break-in cycle is proposed. As validated in several literature
Souza, Rafael BarbosaJunior, Rodrigo Alonso PiresRodrigues, Luiz Fernando AlvesBecker, Giovana StopanovskiFernandes, HederMaia, Thales Alexandre CarvalhoPontes, Diego Augusto
The twin challenges of the automotive industry namely petroleum dependence and environmental pollution paved way for the development of an environmentally friendly and feasible substitute for diesel, possessing power characteristics equivalent to those of a diesel engine. Biofuel has potential as a renewable energy source, offering a more sustainable alternative to traditional fossil fuels. However, it does come with some challenges, such as varying quality and combustion properties. To enhance its performance, engines can be fine-tuned by adjusting fuel injection parameters, such as timing, pressure, and duration. Accordingly, this research article focuses on optimizing the fuel injection parameters for a CRDi engine powered by D+LPO (20% lemon peel oil and 80% diesel) biofuel, with the goal of improving both performance and emission characteristics. The experimental design matrix was generated using Design Expert-13 software, employing the I-optimal technique. Utilizing response
Saiteja, PajarlaAshok, B.
Otto cycle internal combustion engines have undergone technological developments that can be fueled by various types of fuels in different mixture proportions. To achieve this, a detailed study of the main factors that influence the engine combustion process is necessary. The objective of this study is to evaluate the effects of varying the ignition advance on the performance parameters and vibration level of the engine operated with regular gasoline, premium gasoline, ethanol and a mixture of ethanol with regular gasoline. The experimental tests consisted of operating an Otto cycle engine on a bench dynamometer under full load conditions, varying rotation and ignition advance by 5, 10 and 20% in relation to the original ignition advance and correlating the levels of pre-ignition, knock, engine vibration levels with engine performance parameters. The results showed that the engine vibration level was influenced by the type of fuel used, engine performance parameters and the presence of
Santana, Claudio MarcioSantana, Linicker Lopes BrunoAlmeida, Helder Giostri Alves
High and ultra-high pressure direct injection (UHPDI) can enhance efficiency gains with flex-fuel engines operating on ethanol, gasoline, or their mixtures. This application aims to increase the engine’s compression ratio (CR), which uses low CR for gasoline due to the knocking phenomenon. This type of technology, involving injection pressures above 1000 bar, permits late fuel injection during the compression phase, preventing auto-ignition and allowing for higher compression ratios. UHPDI generates a highly turbulent spray with significant momentum, improving air-fuel mix preparation, and combustion, resulting in even greater benefits while minimizing particulate matter emissions. This study aims to develop ultra-high-pressure injection systems using gasoline RON95 and hydrated ethanol in a single-cylinder engine with optical access. Experimental tests will be conducted in an optically accessible spark ignition research engine, employing thermodynamic, optical, and emission results
Malheiro de Oliveira, Enrico R.Mendoza, Alexander PenarandaMartelli, Andre LuizDias, Fábio J.Weissinger, Frederico F.dos Santos, Leila RibeiroLacava, Pedro Teixeira
This study investigates the influence of Silica-Diamond-Like Carbon (Si-DLC) coated pistons on performance metrics of diesel engine fuelled with various blends of Cassia Fistula biodiesel (CFBD10, CFBD20, CFBD30, and CFBD40). The primary focus is on key performance metrics, including Brake Thermal Efficiency (BTE), Brake Specific Energy Consumption (BSEC), and Exhaust Gas Temperature (EGT). The results demonstrated improvement in BTE and EGT, alongside a reduction in BSEC across all biodiesel blends compared to conventional diesel. Specifically, at full engine load, CFBD10 exhibited a BTE of 33.41%, which is 3.17% higher than neat diesel in the stock engine. At part load and no-load scenarios, improvements of 2% and 0.51% over neat diesel were recorded. During no-load conditions, the BSEC for CFBD10 was measured at 9.901 MJ.kW-hr, 0.738 MJ.kW-hr lower than that of neat diesel. Further increases in Cassia fistula blends resulted in higher BSEC values due to lower calorific content
Veeraraghavan, SakthimuruganDe Poures, Melvin VictorMadhu, S.Palani, Kumaran
As a journey to green initiatives, one of the focus areas for automotive industry is reducing environmental impact especially in case of internal combustion engines. Latest digital twin technology enable modelling complicated, fast and unsteady phenomena including the changes of emission gases concentration and output torque observed during diesel emission and combustion process. This paper presents research on the emission and combustion characteristics of a heavy vehicle diesel engine, elaborating an engineered architecture for prognostics/diagnostics, state monitoring, and performance trending of heavy-duty vehicle engine (HDVE) and after treatment system (ATS). The proposed architecture leverages advanced modeling methodologies to ensure precise predictions and diagnostics, using data-driven techniques, the architecture accurately model’s engine and exhaust system behaviors under various operating conditions. For exhaust system, architecture demonstrates encouraging predictive
Singh, PrabhsharnThakare, UjvalHivarkar, Umesh
Looking at the current scenario in transportation industry, in majority of the conventional powertrains, internal combustion (IC) engines fueled by diesel serve as the powerhouse. In all locomotives driven by IC engine, it is essential to monitor critical engine parameters to ensure good engine health and performance. Exhaust temperature of engine is a very critical parameter which gives the information about in-cylinder combustion. In traditional diesel engine layouts, exhaust temperature measurement relies on physical temperature sensor. The proposed methodology is focused on applying the data driven models for providing an estimated value of the exhaust temperature. Based on the estimated value of exhaust temperature, this technique can be used to monitor the IC engine. This methodology uses an advanced Artificial Intelligence technique for providing an accurate estimate of exhaust gas temperature. Real world vehicle data was used for training, validating, and testing the data
Jagtap, Virendra ShashikantGanguly, GouravMitra, Partha
In the last decade, the increased global temperature, stringent regulations, and customer demand for high fuel economy have led to the accelerated development of alternative propulsion solutions, with particular focus on electrified vehicles. Hybrid electric vehicles (HEVs), the combination of electric machinery with conventional powertrains, allows diversifications of powertrain architectures. In addition, it has been demonstrated that engines employing advanced low temperature combustion concepts, such as dual fuel reactivity controlled compression ignition (RCCI), and able to operate on both renewable and conventional fuels, produce ultra-low nitrogen oxides (NOx) and particulate matter (PM) emissions while maintaining thermal efficiency similar to conventional diesel operation at part load operating conditions. This study aims to investigate the potential of integrating a gasoline-diesel RCCI engine in an HEV in achieving reduced fuel consumption and lower NOx and PM emissions
Marwaha, TejasvaKhedkar, Nikhil DilipSarangi, Asish Kumar
This study meticulously examines the ignition coil (IG), a pivotal component in engine operation, which transforms the low voltage from the battery into the high voltage necessary for spark plug electrode flashover, initiating the combustion cycle. Considering the importance of IG coils in engine operation which has a direct impact on the engine performance. Any failure in the IG coils is judged as a critical failure and encompasses severe repercussions. The paper details an investigation into the issue of ‘White Deposition’ on IG coils. White deposit was observed in IG Coils during new model development in bench level durability test. A comprehensive failure analysis was conducted, employing vibration analysis, thermal analysis, and chemical analysis of the white deposits to ascertain the root cause. Subsequent to identifying the root cause, the study elaborated on hardware design enhancements as a solution. These design changes were rigorously tested on engine benches, confirmed for
Patel, Hardik ManubhaiGupta, VineetChand, SubhashKumar, Nitish
The prediction of friction mean effective pressure (FMEP) is important when engine performance is estimated in the model-based development process. The Chen–Flynn model as a function of the maximum in-cylinder pressure (Pmax) and mean piston speed (Cm) is often used to predict FMEP because of its simplicity to utilize; however, this study inferred from the results of multiple regression analysis between FMEP and factors related to combustion phase and rate of heat release profile (ROHR) that the Chen–Flynn model may be difficult to accurately estimate FMEP in a modern diesel engine with common rail fuel injection system, which allows the control of fuel injection pressure (Pinj) and combustion phase. In this study, a neural network with machine learning was applied to predict FMEP based on the expectation that the ROHR profile, which allows the reduction of FMEP may be possible to be found. 7666 points experimental results that include FMEP and combustion parameters in the heavy-duty
Yamaguchi, TakuyaUchida, NoboruWatanabe, KazumasaHattori, Yuki
One of the advantages of the internal combustion engine is that it can function with relatively simple intake air filtration. Provided that dust is kept out, air entering the engine can ensure that the necessary combustion process takes place. So, a relatively simple dust filter will do the job. By comparison, hydrogen fuel cells are far more sensitive to air quality. Other pollutants can affect both fuel-cell performance and the lifetime of the fuel-cell stack. At the recent IAA Transportation Show in Hanover, Germany, Donaldson Filtration Solutions displayed tailored solutions through its range of cathode air filters. These typically rely on multiple layers - including activated carbon, an acid and base layer, and a dust filter - to screen out sulphur dioxide, nitrogen oxides and ammonia, while allowing for customization to protect against butane, toluene and other unwanted compounds
Kendall, JohnGehm, Ryan
Backed by a consortium of companies, Southwest Research Institute's demonstrator vehicle aims to prove the commercial viability of hydrogen engines for on-road trucks. For decades, the running joke around hydrogen being a viable fuel for commercial trucks has been that it's “ten years away from being ten years away.” Though hydrogen-fueled rigs operating at scale has long seemed like a pipe dream, shifting winds around the globe blowing towards decarbonization have finally pushed this technology to be ready for the road. With the demand for the development of new propulsion technologies rising, organizations such as the Southwest Research Institute (SwRI) have ramped up R&D efforts to make this tech commercially viable. SwRI is an independent provider of research services and can rapidly assemble teams to tackle problems. SwRI's main mission is to push the boundaries of science and technology to develop innovative solutions
Wolfe, Matt
Agriculture, industrial, mining, construction, freight transport and other major global economy sectors rely on vehicle power to thrive. “Internal combustion engines - those powered by gasoline, diesel, natural gas or propane - really are key to our current economy, and we see [the ICE] as a key part of our energy future,” Allen Schaeffer, executive director of the Engine Technology Forum, a U.S.-based educational organization, said during a September webinar. Hosted by the Engine Technology Forum, the “Taking Internal Combustion Engines to the Next Level” session focused on current and under-development innovations aimed at increasing engine efficiency and lowering emissions
Buchholz, Kami
This study investigated the contact pressure distribution of three combustion seal designs for fuel injectors using both experimental techniques and finite element analysis (FEA). The designs tested included the baseline seal (Design #1), a conical seal (Design #2), and the current production seal (Design #3). In phase 1, a 2D axisymmetric FEA was conducted under worst-case torque conditions (67.8 Nm) to simulate contact pressure, with an axial load of 10 kN and combustion pressure of 21.3 MPa applied to the injector assembly. Phase 2 employed Fuji films to measure the pressure distribution at higher torques (89.5 and 115.2 Nm) in a more realistic scenario, incorporating challenges such as misalignment and eccentric loading. During this phase, Fuji film shearing was a significant challenge, complicating the accurate assessment of pressure profiles. Design #1 failed to maintain the minimum threshold contact pressure of 70 MPa over a 1 mm length, leading to potential leakage. Design #2
Kaliyanda, Aneesh
ABSTRACT Cylinder Pressure Monitoring (AVL CYPRESS™) is a technology which provides closed-loop feedback to enable real-time control of combustion in a compression ignition engine. This makes it possible to adapt to the fuel ignition quality and energy density by adjusting the main injection quantity and the placement of the injection events. The engine control system can thus detect fuel quality and adapt the combustion phasing quickly and robustly – and without any prior knowledge of fuel properties. By using a cylinder pressure sensor(s), the engine controller will be able to map the development of the apparent rate of heat release (ARHR) and the mass fuel burn curve - which provides good thermal efficiency correlation. The cylinder pressure map detects the combustion event and the feedback controller adjusts the start of injection to maintain the combustion event at the desired crank position. The cylinder pressure sensor allows for accurate measurement of the power produced. By
Johnson, GustavHunter, Gary
ABSTRACT Single-Fuel Concept (SFC) describes the desire to operate diesel engines using JP-8 as the only fuel in the US military due to mostly logistic reasons. However, there is a lack of a fundamental database on the combustion characteristics of JP-8 compared to those studies that have been done for diesel combustion. In this current study, several kinetic models are used to look into flame properties including ignition behavior, fuel properties including evaporation characteristics, and species evolution such as soot precursor, acetylene. Several surrogates for JP-8 fuel including tetradecane, n-dodecane and a mixture of 77 vol-% n-dodecane and 23 vol-% m-xylene are selected in the model using a detailed chemical kinetic mechanism with 330 species and 1957 reactions. Included in the model are growth mechanisms of Polycyclic Aromatic Hydrocarbon (PAH), which are known to be important for soot formation. Studies are performed to describe the fundamental combustion characteristics of
Cung, Khanh D.Johnson, Jaclyn E.Zhang, AnqiNaber, Jeffrey D.Lee, Seong-Young
ABSTRACT Problems resulting from the use of low-Cetane Number (CN) JP-8 in military diesel engines are mainly caused by the poor autoignition quality of the fuel that requires a long period between the start of injection and the start of combustion. A detailed analysis of the processes which occur during the ignition delay period clearly shows that the start of combustion is preceded by a long period where the Low Temperature (LT) combustion chemistry (cool flame) prevails in which the rates of burning are very limited. Under certain operating conditions, the LT combustion regime is associated with the Negative Temperature Coefficient (NTC) regime, which adds to the length of the ignition delay period. The details of these regimes are examined by using computer simulation codes. In addition, the autoignition characteristics of JP-8 with a wide range of cetane numbers are investigated and compared with ULSD (Ultra Low Sulfur Diesel) and a Fischer-Tropsch Synthetic Paraffinic Kerosene
Henein, NaeimBryzik, WalterJayakumar, ChandrasekharanSattler, Eric R.Johnson, Nicholas C.Hubble, Nichole K.
ABSTRACT 3D printing is a rapidly evolving technique for alternative piston manufacturing that offers the ability to realize complex combustion bowl geometry, robust structure and advanced cooling channel geometries while delivering precise tolerance and mass control. IAV has designed, analyzed, optimized and produced 3D printed pistons for heavy-duty diesel engines. The key features include an innovative form of combustion bowl, 300 bar peak cylinder pressure capability and advanced cooling channels in a mass neutral to less capable design. During 2018, these pistons will undergo fired engine testing
Dolan, RobertBudde, RogerSchramm, ChristianRezaei, Reza
ABSTRACT This work investigates non-traditional operating modes of a diesel engine that allow the tailoring of acoustic, smoke and thermal signatures for unique unmanned ground vehicle (UGV) military applications. A production, air-cooled single-cylinder diesel engine having a mechanical fuel injection system has been retrofit with a flexible common-rail injection and electronic control system. The experimental domain explores the effects of the injection timing and pressure on the engine’s acoustic, smoke and heat signatures through analysis of the in-cylinder combustion processes. Surface maps of loudness, exhaust temperature and exhaust smoke density over the range of fuel injection strategies are presented, illustrating the degree to which each signature may be controlled. Trade-offs between the signature modes are presented and discussed. The results demonstrate the possibility of providing military UGVs the capability to tailor their acoustic, infrared and smoke signatures
Jansons, MarcisKhaira, SukhbirBryzik, Walter
ABSTRACT The effects of advanced fuel injection strategies on the combustion behavior of an unblended low-cetane synthetic jet fuel (Sasol isoparaffinic kerosene, POSF 7629, derived cetane number 31) were investigated in a single-cylinder research engine (SCRE) at several speeds and loads. The most significant finding of the current work is that the introduction of a small pulse of fuel prior to the main fuel injection event, termed a close-coupled pilot (CCP) injection, effectively mitigates the relatively longer ignition delay time of the DCN 31 fuel. Therefore, a potential technical solution exists that would permit the use of low-cetane jet fuels in military ground vehicles if the operational scenario required it. Citation: M. Tess, E. Gingrich, S. Stoll, “Combustion Strategies for Low-Cetane Fuels”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 13-15, 2019
Tess, MichaelGingrich, EricStoll, Steve
ABSTRACT The majority of commercial off the shelf (COTS) diesel engines rely on EGR to meet increasingly stringent emissions standards, but these EGR systems would be susceptible to corrosion and damage if JP-8 were used as a fuel due to its high sulfur content. Starting with a Cummins 2007 ISL 8.9L production engine, this program demonstrates the modifications necessary to remove EGR and operate on JP-8 fuel with a goal of demonstrating 48% brake thermal efficiency (BTE) at an emissions level consistent with 1998 EPA standards. The effects of injector cup flow, improved turbo match, increased compression ratio with revised piston bowl geometry, increased cylinder pressure, revised intake manifold for improved breathing, and piston, ring and liner designs to reduce friction are all investigated. Testing focused on a single operating point, full load at 1600 RPM. This engine uses a variable geometry turbo and high pressure common rail fuel system, allowing control over air fuel ratio
Lutz, TimModiyani, Rajani
ABSTRACT ACT's non-catalytic, sulfur-tolerant “Swiss-roll” reforming technology is an effective way to provide the required reformate composition for the Army’s SOFC system. This technology will enable DoD to implement efficient and low acoustic signature Solid Oxide Fuel Cell (SOFC) system in the field and satisfy the Single Fuel Policy. While the high sulfur content of JP-8 and coke formation pose significant challenges for catalytic-based reforming systems, the thermal partial oxidation based reformer is comparatively less complex, highly compact, lightweight and requires minimal power consumption. These advantages allow for a fuel cell fed with JP-8 be implemented in a transportable system, such as ground vehicle, with low acoustic signature for the US Army
Chen, Chien-HuaPearlman, HowardZelinsky, RyanCrawmer, JoelRichard, BradleyRonney, Paul
ABSTRACT The Opposed Piston Engine is a highly advantageous architecture for military applications due to its power density and efficiency, and the U.S. Army is investing to develop OP engines for Combat Applications. The Cummins / Achates Power team was selected to design, procure, build, test, and advance to TRL 9 the first configuration of a scalable Opposed Piston Engine that can then be used to grow a family of OP Engines across all Combat and Tactical Vehicles. At the same time CALSTART is leading a companion project to demonstrate the Opposed Piston technology in commercial Class 8 trucks. This paper analyzes the commercialization and militarization potential of Opposed Piston technology and attempts to identify the ideal OP Engine configurations to meet those applications. Citation: S. Sokolsky, J. Major, “Advanced Combat Engine Militarization and Commercialization Study”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI
Sokolsky, StevenMajor, John
SUMMARY Autonomous operation of diesel engines using different military fuels faces many challenges. Engines should be able to use Jet Propellant-8 (JP-8) fuel, as well as alternate and renewable fuels intended to replace petroleum-derived jet or diesel fuels. These fuels can have wide ranges of physical and chemical properties. In addition, diesel engines that power military ground vehicles are originally manufactured for commercial applications which are equipped with additional after treatment devices needed to the meet emission standards. Such devices are not needed in military vehicles. However, commercial engines and after treatment devices are calibrated as one system to meet the emission targets, causing some penalty in fuel economy and peak power. These engines should be recalibrated to produce the highest power density and the best fuel economy required in military vehicles. Furthermore, commercial engines are optimized to operate on ULSD (Ultra Low Sulfur Diesel) fuel, which
Henein, Naeim. A.Bryzik, WalterBadawy, TamerMuzzell, Pat.Schihl, PeteSattler, EricJohnson, Nick
ABSTRACT Cylinder Pressure Monitoring (AVL CYPRESS™) is a technology which provides closed-loop feedback to enable real-time control of combustion in a compression ignition engine. This makes it possible to adapt to the fuel ignition quality and energy density by adjusting the main injection quantity and the placement of the injection events. The engine control system can thus detect fuel quality and adapt the combustion phasing quickly and robustly – and without any prior knowledge of fuel properties. By using a cylinder pressure sensor(s), the engine controller will be able to map the development of the apparent rate of heat release (ARHR) and the mass fuel burn curve - which provides good thermal efficiency correlation. The cylinder pressure map detects the combustion event and the feedback controller adjusts the start of injection to maintain the combustion event at the desired crank position. The cylinder pressure sensor allows for accurate measurement of the power produced. By
Johnson, Gustav
ABSTRACT Cylinder Pressure Monitoring (CYPRESS™). This technology provides closed-loop feedback to enable a real-time calculation of the apparent heat release rate (AHRR). This makes it possible to adapt to the fuel ignition quality (cetane number) by adjusting the pilot injection quantity and the placement of the pilot and main injection events. This enables the engine control system to detect fuel quality and adapt the ignition sequence accordingly. This technology is also used to infer the total fuel energy injected by analyzing the AHRR, making it possible to vary the injected fuel volume quantity to achieve consistent (+/- 2%) full load power as the fuel energy density varies. Analysis of the position of AHRR with respect to the crank angle (CA) is dependent on the start of injection and subsequent fuel shots. The ability to control the position of the AHRR maintains thermal efficiency as fuel properties vary which are implemented by controlling the fuel injection pulse widths and
Jeal, GeoffHunter, Gary L.Kruit, Stephan L.
ABSTRACT The US Army is seeking improvements in the fuel efficiency of their military vehicles.. They have initiated a number of R&D projects aimed at advancing the state-of-the-art of powertrain efficiency including demonstration in a laboratory environment. This effort will set a benchmark for the vehicle integrators, allowing them to improve future vehicle offerings. The SAIC, AVL, Badenoch, QinetiQ and Ker-Train Research team offered powertrain solutions from 7 Tons to 40 Tons that achieved the goal of 44% thermal efficiency and the stringent flexible fuel and emissions requirements. In each of these offerings the team was able to identify modifications to existing engines that allowed dramatic improvements in the thermal efficiency. These efficiency improvements were achieved through a combination of techniques, combustion cycle adjustments using in-cylinder pressure monitoring and precise control of fuel injector timing, and turbo-compounding. For the R&D project, the fuel
McDowell, JimHunter, Gary L.Hennessy, Chris
ABSTRACT The latest advancements in common rail fuel injection system, material science, engine control strategies, and manufacturing technologies have challenged and allowed engine designers to create a high power density, fuel efficient, reliable, and environmental friendly multi-fuel engine. To increase power density a novel high-speed 2-stroke turbocharged compression ignition engine will feed the pressurized air directly into the combustion chamber without going through the crankcase. Thus, only pressurized clean air will be used for combustion and oil consumption will be dramatically reduced. To further improve volumetric efficiency and reduce emissions, a computer controlled dynamic variable valve timing system can be incorporated such that the optimum amount of pressurized air will be available for combustion at various loads and conditions. Combustion efficiency at different loads can be optimized by adjusting the compression ratio dynamically through computer control. By
Chue, Stephen
ABSTRACT This paper describes the approach used to improve the fuel flexibility of a high power density diesel engine intended for tactical combat applications. The objective of this work was to demonstrate a technically feasible solution that mitigated the negative performance impacts encountered when commercial and military-grade aviation fuels are used in diesel engines that were calibrated with standard Type 2 diesel fuel. To accomplish this objective, modifications to the engine calibration and the implementation of a fuel compensation algorithm, which used cylinder pressure feedback, resulted in successful demonstration of meeting the program requirements of maintaining acceptable combustion quality and maximum power output to within ± 2 percent of the rated power target regardless of the fuel type supplied to the engine
Neely, GaryNg, CheukReinhart, ThomasCoppersmith, RobertCombi, Anthony
ABSTRACT This paper discusses the design and performance results of a modular designed spark ignited rotary engine Auxiliary Power Unit (APU) fueled by JP-8. This APU is intended for use onboard tactical and combat vehicles applications where packaging space and weight are at a premium. The platform is flexible and scalable to allow for application to the full portfolio of tactical and combat systems. Such an APU would enable the Army to realize significant cost savings in terms of fuel and fuel support, as well as enable enhanced operation modes of existing vehicles by enabling Silent Watch capability
Stein, JoshuaTroia, JosephTruemner, RussellHunter, Gary
ABSTRACT Extensive studies have been completed for diesel engine high pressure injection on spray and combustion characteristics with diesel fuel. However the US military’s objective is to use JP-8 as a replacement to diesel fuel, which has limited spray and combustion information available. The differences between JP-8 and diesel in terms of fuel properties translate to differing spray and combustion characteristics. To fulfill the Single-Fuel Concept of the military and incorporate JP-8 fuels, knowledge of the fuels spray, vaporization, and combustion behavior is imperative for determining fuel impact on performance. This work quantifies vaporizing spray characteristics of vapor penetration and vaporizing liquid length using high speed imaging methods of combined Mie-scatter and Schlieren in a constant volume combustion vessel. Studies are undertaken at a constant injection pressure of 700 bar, at temperatures of 800, 946, and 1150 K at a density of 24.1 kg/m3. Tetradecane is used as
Johnson, Jaclyn E.Cung, Khanh D.Zhang, AnqiNaber, Jeffrey D.Lee, Seong-Young
Based on a single-cylinder optical engine and a high-speed camera combustion analysis system, experiments were conducted to study the effects of main injection timing and pre-injection equivalence ratio (ratio of MF fuel to total fuel mass in reactivity-controlled compression ignition [RCCI] combustion mode) on the combustion characteristics and combustion process of RCCI, and at the same time compared and analyzed with pure diesel combustion. The results show that with the advance of the main injection timing, the ignition delay appears to be advanced and then delayed, the combustion phase is advanced as a whole, and the combustion duration is prolonged. Compared with the pure diesel combustion mode, a smaller pre-injection equivalence ratio of RCCI combustion mode delays the ignition delay, and a further increase in the pre-injection equivalence ratio advances the ignition delay. Changing the pre-injection equivalence ratio causes less change in the combustion phase, and the
Huang, BinYu, WenbinYuan, ZinengYang, Ansheng
Dimethyl ether (DME) is a promising substitute for diesel as a fuel in heavy-duty engines. This article presents the comparison between a diesel- and a DME-powered compression ignition engine. The diesel-powered version was initially characterised at a range of operating points before being converted to operate on DME. This was achieved by replacing fuel system components with bespoke DME-compatible engine parts. An off-board fuel pressurisation and conditioning system was designed to replace the existing high-pressure fuel pump, while maintaining all other engine hardware and components. Engine behaviour, in terms of combustion and emissions on both fuels was examined. Firstly, the effect of varying recirculated exhaust gas (EGR) concentration at constant excess air ratio, combustion phasing (CA50) and equal fuel delivery rate (by energy input) was interrogated. DME combustion was significantly faster, as combustion duration was reduced by around 30%, in some cases, when comparing to
Apostolou, ChristosElliott, ThomasRutledge, JohnButcher, DanielLong, EdwardSpencer, Adrian
Sustainable Aviation Fuels (SAFs) offer great promises towards decarbonizing the aviation sector. Due to the high safety standards and global scale of the aviation industry, SAFs pose challenges to aircraft engines and combustion processes, which must be thoroughly understood. Soot emissions from aircrafts play a crucial role, acting as ice nuclei and contributing to the formation of contrail cirrus clouds, which, in turn, may account for a substantial portion of the net radiative climate forcing. This study focuses on utilizing detailed kinetic simulations and soot modeling to investigate soot particle generation in aero-engines operating on SAFs. Differences in soot yield were investigated for different fuel components, including n-alkanes, iso-alkanes, cycloalkanes, and aromatics. A 0-D simulation framework was developed and utilized in conjunction with advanced soot models to predict and assess soot processes under conditions relevant to aero-engine combustion. The simulations
Yi, JunghwaManin, JulienWan, KevinLopez Pintor, DarioNguyen, TuanDempsey, Adam
With all the environmental concern of diesel fuelled vehicle, it is a challenge to phase out them completely specifically from Heavy duty application. Most pragmatic solution lies in solutions which improves the fuel economy and reduce the carbon emission of existing diesel fuelled vehicle fleet and retain the economic feasibility offered by present diesel fuelled vehicle fleets. With implementation of Bharat Stage IV (BS VI) emission norms across country from April 2020, supply of BS VI complaint diesel fuel started and BS VI complaint vehicles with upgraded engine technologies and after treatment devices started to come which made present vehicle fleets heterogeneous with substantive number of BS IV vehicle. Beside improvement of engine technologies, existing BS IV vehicle fleet performance can be enhanced through improved fuel and lubricants solutions. The present research work is a step towards improving the fuel economy of existing BS IV diesel vehicles through the intervention of
Mishra, Sumit KumarSingh, Punit KumarChakradhar, MayaSeth, SaritaSingh, SauhardArora, AjayHarinarain, Ajay KumarMaheshwari, Mukul
A comprehensive experimental study of hydrogen–diesel dual-fuel and hydrogen-hydrotreated vegetable oil (HVO) dual-fuel operations was conducted in a single-cylinder diesel engine (bore 85.0 mm, stroke 96.9 mm, and compression ratio 14.3) equipped with a common rail fuel injection system and a supercharger. The hydrogen flow rate was manipulated by varying the hydrogen excess air ratio from 2.5 to 4.0 in 0.5 increments. Hydrogen was introduced into the intake pipe using a gas injector. Diesel fuel and HVO were injected as pilot fuels at a fixed injection pressure of 80 MPa. The quantity of pilot fuel was set to 3, 6, and 13 mm3/cycle. The intake and exhaust pressures were set in the range of 100–220 kPa in 20 kPa increments. The engine was operated at a constant speed of 1,800 rpm under all conditions. The pilot injection timing was varied such that the ignition timing was constant at the TDC under all conditions. The results demonstrated that smoke was lower when HVO was used as the
Mukhtar, Ghazian AminTange, KotaNakatani, SatoshiHoribe, NaotoKawanabe, HiroshiMorita, GinHiraoka, KenjiKoda, Kazuyuki
Diesel engines are largely used as power units with high fuel efficiency. Conversely, they have an adverse impact on the environment and human health as they emit high NOx and particulate matter emissions. As more stringent regulations for emissions are introduced, low temperature combustion strategy such as Gasoline Compression Ignition evolved and demonstrated the potential to reduce the particulate matter and NOx emissions by operating engines under a Partially Premixed Combustion mode. Therefore, a 0.55 mm single cylinder engine (Gasoline Direct Injection), was tested over range of engine loads with constant speed (1500 rpm) using RON80 without oxygenates. Different operating parameters such as injection, exhaust gas recirculation (EGR) etc. were used to control combustion phasing and mixture stratifications. At low loads, rebreathing of hot exhaust gas produced low levels of NOx and smoke emissions. It reduced NOx by 60% and smoke levels below 0.20 FSN when it is coupled with low
Qahtani, Yasser AlSellnau, MarkYu, Xin
Catalyst heating operation in compression-ignition engines is critical to ensure rapid light-off of exhaust catalysts during cold-start. This is typically achieved by using late post injections for increased exhaust enthalpy, which retardability is constrained by acceptable CO and unburned hydrocarbons emissions, since they are directly emitted through the tailpipe due to the inactivity of the oxidation catalyst at these conditions. Post-injection retardability has shown to be affected by the cetane number of the fuel, but it is unclear how other fuel properties affect the ability to retard the combustion. This study aims to understand the impact of the distillation characteristics of the fuel on the performance of catalyst heating operation and on post-injection retardability. In this study, experiments are performed in a single-cylinder medium-duty diesel engine fueled with three full boiling-range diesel fuels with different distillation curves using a five-injection strategy (two
Lee, SangukLopez Pintor, DarioCho, SeokwonBusch, Stephen
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