The Potential of Using Natural Gas in HCCI Engines

Download The Potential of Using Natural Gas in HCCI Engines PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (85 download)

DOWNLOAD NOW!


Book Synopsis The Potential of Using Natural Gas in HCCI Engines by : Junnian Zheng

Download or read book The Potential of Using Natural Gas in HCCI Engines written by Junnian Zheng and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the depletion of petroleum based fuels and the corresponding concerns of national energy security issues, natural gas as an alternative fuel in IC engine applications has become an attractive option. Natural gas requires minimum mixture preparation, and is chemically stable, both of which make it a suitable fuel for homogeneous charged compression ignition (HCCI) engines. Compared to petroleum based fuels, natural gas produces less green-house emissions. However, natural gas is hard to auto-ignite and therefore requires a higher compression ratio, some amount of intake heating, or some type of pre-ignition. In addition, natural gas usually has large differences in fuel composition from field to field, which adds more uncertainties for engine applications. The current study determines the auto-ignition characteristics, engine performance, and nitric oxides emissions as functions of major operating parameters for a natural gas fueled HCCI engine, and determines differences relative to gasoline fueled HCCI engines which have been studied for many years. These tasks have been done using both zero- and multi-dimensional engine simulations. By zero-dimensional simulation, the effects of varying equivalence ratios, engine speeds, compression ratio, EGR level, intake pressure and fuel compositions are determined and analyzed in detail. To be able to account for the in-cylinder inhomogeneous effect on the HCCI combustion, multi-zone models coupled with cold-flow CFD simulations are employed in addition to the single-zone model. The effects of non-homogeneous temperature and equivalence ratio stratification on the ignition timing, combustion phasing, and emissions formation have been studied and discussed. Finally, the preliminary two-dimensional axial-symmetric CFD simulations have been conducted to study the in-cylinder temperature and the species distributions, which provide better visualization of the natural gas auto-ignition process.

Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles

Download Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles PDF Online Free

Author :
Publisher : National Academies Press
ISBN 13 : 0309373913
Total Pages : 812 pages
Book Rating : 4.3/5 (93 download)

DOWNLOAD NOW!


Book Synopsis Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles by : National Research Council

Download or read book Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles written by National Research Council and published by National Academies Press. This book was released on 2015-09-28 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt: The light-duty vehicle fleet is expected to undergo substantial technological changes over the next several decades. New powertrain designs, alternative fuels, advanced materials and significant changes to the vehicle body are being driven by increasingly stringent fuel economy and greenhouse gas emission standards. By the end of the next decade, cars and light-duty trucks will be more fuel efficient, weigh less, emit less air pollutants, have more safety features, and will be more expensive to purchase relative to current vehicles. Though the gasoline-powered spark ignition engine will continue to be the dominant powertrain configuration even through 2030, such vehicles will be equipped with advanced technologies, materials, electronics and controls, and aerodynamics. And by 2030, the deployment of alternative methods to propel and fuel vehicles and alternative modes of transportation, including autonomous vehicles, will be well underway. What are these new technologies - how will they work, and will some technologies be more effective than others? Written to inform The United States Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) Corporate Average Fuel Economy (CAFE) and greenhouse gas (GHG) emission standards, this new report from the National Research Council is a technical evaluation of costs, benefits, and implementation issues of fuel reduction technologies for next-generation light-duty vehicles. Cost, Effectiveness, and Deployment of Fuel Economy Technologies for Light-Duty Vehicles estimates the cost, potential efficiency improvements, and barriers to commercial deployment of technologies that might be employed from 2020 to 2030. This report describes these promising technologies and makes recommendations for their inclusion on the list of technologies applicable for the 2017-2025 CAFE standards.

Natural Gas Engines

Download Natural Gas Engines PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9811333076
Total Pages : 419 pages
Book Rating : 4.8/5 (113 download)

DOWNLOAD NOW!


Book Synopsis Natural Gas Engines by : Kalyan Kumar Srinivasan

Download or read book Natural Gas Engines written by Kalyan Kumar Srinivasan and published by Springer. This book was released on 2018-11-03 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the various advanced reciprocating combustion engine technologies that utilize natural gas and alternative fuels for transportation and power generation applications. It is divided into three major sections consisting of both fundamental and applied technologies to identify (but not limited to) clean, high-efficiency opportunities with natural gas fueling that have been developed through experimental protocols, numerical and high-performance computational simulations, and zero-dimensional, multizone combustion simulations. Particular emphasis is placed on statutes to monitor fine particulate emissions from tailpipe of engines operating on natural gas and alternative fuels.

HCCI and CAI Engines for the Automotive Industry

Download HCCI and CAI Engines for the Automotive Industry PDF Online Free

Author :
Publisher : CRC Press
ISBN 13 :
Total Pages : 562 pages
Book Rating : 4.F/5 ( download)

DOWNLOAD NOW!


Book Synopsis HCCI and CAI Engines for the Automotive Industry by : Hua Zhao

Download or read book HCCI and CAI Engines for the Automotive Industry written by Hua Zhao and published by CRC Press. This book was released on 2007-09-10 with total page 562 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous charge compression ignition (HCCI)/controlled auto-ignition (CAI) has emerged as one of the most promising engine technologies with the potential to combine fuel efficiency and improved emissions performance, offering reduced nitrous oxides and particulate matter alongside efficiency comparable with modern diesel engines. Despite the considerable advantages, its operational range is rather limited and controlling the combustion (timing of ignition and rate of energy release) is still an area of on-going research. Commercial applications are, however, close to reality. HCCI a.

Development and Testing of a 6-Cylinder HCCI Engine for Distributed Generation

Download Development and Testing of a 6-Cylinder HCCI Engine for Distributed Generation PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 23 pages
Book Rating : 4.:/5 (316 download)

DOWNLOAD NOW!


Book Synopsis Development and Testing of a 6-Cylinder HCCI Engine for Distributed Generation by : R. Dibble

Download or read book Development and Testing of a 6-Cylinder HCCI Engine for Distributed Generation written by R. Dibble and published by . This book was released on 2005 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the technical approach for converting a Caterpillar 3406 natural gas spark ignited engine into HCCI mode. The paper describes all stages of the process, starting with a preliminary analysis that determined that the engine can be operated by preheating the intake air with a heat exchanger that recovers energy from the exhaust gases. This heat exchanger plays a dual role, since it is also used for starting the engine. For start-up, the heat exchanger is preheated with a natural gas burner. The engine is therefore started in HCCI mode, avoiding the need to handle the potentially difficult transition from SI or diesel mode to HCCI. The fueling system was modified by replacing the natural gas carburetor with a liquid petroleum gas (LPG) carburetor. This modification sets an upper limit for the equivalence ratio at {phi} {approx} 0.4, which is ideal for HCCI operation and guarantees that the engine will not fail due to knock. Equivalence ratio can be reduced below 0.4 for low load operation with an electronic control valve. Intake boosting has been a challenge, as commercially available turbochargers are not a good match for the engine, due to the low HCCI exhaust temperature. Commercial introduction of HCCI engines for stationary power will therefore require the development of turbochargers designed specifically for this mode of operation. Considering that no appropriate off-the-shelf turbocharger for HCCI engines exists at this time, we are investigating mechanical supercharging options, which will deliver the required boost pressure (3 bar absolute intake) at the expense of some reduction in the output power and efficiency. An appropriate turbocharger can later be installed for improved performance when it becomes available or when a custom turbocharger is developed. The engine is now running in HCCI mode and producing power in an essentially naturally aspirated mode. Current work focuses on developing an automatic controller for obtaining consistent combustion in the 6 cylinders. The engine will then be tested for 1000 hours to demonstrate durability. This paper presents intermediate progress towards development of an HCCI engine for stationary power generation and next steps towards achieving the project goals.

Chemical Kinetics and Mechanism

Download Chemical Kinetics and Mechanism PDF Online Free

Author :
Publisher : Royal Society of Chemistry
ISBN 13 : 1847557805
Total Pages : 266 pages
Book Rating : 4.8/5 (475 download)

DOWNLOAD NOW!


Book Synopsis Chemical Kinetics and Mechanism by : M Mortimer

Download or read book Chemical Kinetics and Mechanism written by M Mortimer and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: Chemical Kinetics and Mechanism considers the role of rate of reaction. It begins by introducing chemical kinetics and the analysis of reaction mechanism, from basic well-established concepts to leading edge research. Organic reaction mechanisms are then discussed, encompassing curly arrows, nucleophilic substitution and E1 and E2 elimination reactions. The book concludes with a Case Study on Zeolites, which examines their structure and internal dimensions in relation to their behaviour as molecular sieves and catalysts. The accompanying CD-ROM contains the "Kinetics Toolkit", a graph-plotting application designed for manipulation and analysis of kinetic data, which is built into many of the examples, questions and exercises in the text. There are also interactive activities illustrating reaction mechanisms. The Molecular World series provides an integrated introduction to all branches of chemistry for both students wishing to specialise and those wishing to gain a broad understanding of chemistry and its relevance to the everyday world and to other areas of science. The books, with their Case Studies and accompanying multi-media interactive CD-ROMs, will also provide valuable resource material for teachers and lecturers. (The CD-ROMs are designed for use on a PC running Windows 95, 98, ME or 2000.)

Which Fuels for Low CO2 Engines?

Download Which Fuels for Low CO2 Engines? PDF Online Free

Author :
Publisher : Editions TECHNIP
ISBN 13 : 9782710808510
Total Pages : 252 pages
Book Rating : 4.8/5 (85 download)

DOWNLOAD NOW!


Book Synopsis Which Fuels for Low CO2 Engines? by : Pierre Duret

Download or read book Which Fuels for Low CO2 Engines? written by Pierre Duret and published by Editions TECHNIP. This book was released on 2004 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Throughout the world, research and development in the field of vehicle transportation is increasingly focusing on engine and fuel combinations. The conventional and alternative fuels of the future are seen as fundamental to the development of a new generation of internal combustion engines that attain low well-to-wheel CO2 emissions along with near-zero pollutant emissions. These issues were debated during an international conference whose proceedings are presented in this book. This international conference attracted specialists in the field, including participants from universities, research centres and industry.Contents : Future of liquid fuels, Engine and fuel-related issues in HCCI & CAI combustion, Energy conversion in engines from natural gas, Use of hydrogen in IC engines, Which fuels for low CO2 engines?

Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME.

Download Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME. PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (727 download)

DOWNLOAD NOW!


Book Synopsis Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME. by :

Download or read book Evaluation of Technical Feasibility of Homogeneous Charge Compression Ignition (HCCI) Engine Fueled with Hydrogen, Natural Gas, and DME. written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the proposed project was to confirm the feasibility of using blends of hydrogen and natural gas to improve the performance, efficiency, controllability and emissions of a homogeneous charge compression ignition (HCCI) engine. The project team utilized both engine simulation and laboratory testing to evaluate and optimize how blends of hydrogen and natural gas fuel might improve control of HCCI combustion. GTI utilized a state-of-the art single-cylinder engine test platform for the experimental work in the project. The testing was designed to evaluate the feasibility of extending the limits of HCCI engine performance (i.e., stable combustion, high efficiency and low emissions) on natural gas by using blends of natural gas and hydrogen. Early in the project Ricardo provided technical support to GTI as we applied their engine performance simulation program, WAVE, to our HCCI research engine. Modeling support was later provided by Digital Engines, LLC to use their proprietary model to predict peak pressures and temperatures for varying operating parameters included in the Design of Experiments test plan. Digital Engines also provided testing support for the hydrogen and natural gas blends. Prof. David Foster of University of Wisconsin-Madison participated early in the project by providing technical guidance on HCCI engine test plans and modeling requirements. The main purpose of the testing was to quantify the effects of hydrogen addition to natural gas HCCI. Directly comparing straight natural gas with the hydrogen enhanced test points is difficult due to the complexity of HCCI combustion. With the same air flow rate and lambda, the hydrogen enriched fuel mass flow rate is lower than the straight natural gas mass flow rate. However, the energy flow rate is higher for the hydrogen enriched fuel due to hydrogen's significantly greater lower heating value, 120 mJ/kg for hydrogen compared to 45 mJ/kg for natural gas. With these caveats in mind, an analysis of test results indicates that hydrogen enhanced natural gas HCCI (versus neat natural gas HCCI at comparable stoichiometry) had the following characteristics: (1) Substantially lower intake temperature needed for stable HCCI combustion; (2) Inconclusive impact on engine BMEP and power produced; (3) Small reduction in the thermal efficiency of the engine; (4) Moderate reduction in the unburned hydrocarbons in the exhaust; (5) Slight increase in NOx emissions in the exhaust; (6) Slight reduction in CO2 in the exhaust; and (7) Increased knocking at rich stoichiometry. The major accomplishments and findings from the project can be summarized as follows: (1) A model was calibrated for accurately predicting heat release rate and peak pressures for HCCI combustion when operating on hydrogen and natural gas blends. (2) A single cylinder research engine was thoroughly mapped to compare performance and emissions for micro-pilot natural gas compression ignition, and HCCI combustion for neat natural gas versus blends of natural gas and hydrogen. (3) The benefits of using hydrogen to extend, up to a limit, the stable operating window for HCCI combustion of natural gas at higher intake pressures, leaner air to fuel ratios or lower inlet temperatures was documented.

Control and Robustness Analysis of Homogeneous Charge Compression Ignition Using Exhaust Recompression

Download Control and Robustness Analysis of Homogeneous Charge Compression Ignition Using Exhaust Recompression PDF Online Free

Author :
Publisher : Stanford University
ISBN 13 :
Total Pages : 201 pages
Book Rating : 4.F/5 ( download)

DOWNLOAD NOW!


Book Synopsis Control and Robustness Analysis of Homogeneous Charge Compression Ignition Using Exhaust Recompression by : Hsien-Hsin Liao

Download or read book Control and Robustness Analysis of Homogeneous Charge Compression Ignition Using Exhaust Recompression written by Hsien-Hsin Liao and published by Stanford University. This book was released on 2011 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been an enormous global research effort to alleviate the current and projected environmental consequences incurred by internal combustion (IC) engines, the dominant propulsion systems in ground vehicles. Two technologies have the potential to improve the efficiency and emissions of IC engines in the near future: variable valve actuation (VVA) and homogeneous charge compression ignition (HCCI). IC engines equipped with VVA systems are proven to show better performance by adjusting the valve lift and timing appropriately. An electro-hydraulic valve system (EHVS) is a type of VVA system that possesses full flexibility, i.e., the ability to change the valve lift and timing independently and continuously, making it an ideal rapid prototyping tool in a research environment. Unfortunately, an EHVS typically shows a significant response time delay that limits the achievable closed-loop bandwidth and, as a result, shows poor tracking performance. In this thesis, a control framework that includes system identification, feedback control design, and repetitive control design is presented. The combined control law shows excellent performance with a root-mean-square tracking error below 40 [Mu]m over a maximum valve lift of 4 mm. A stability analysis is also provided to show that the mean tracking error converges to zero asymptotically with the combined control law. HCCI, the other technology presented in this thesis, is a combustion strategy initiated by compressing a homogeneous air-fuel mixture to auto-ignition, therefore, ignition occurs at multiple points inside the cylinder without noticeable flame propagation. The result is rapid combustion with low peak in-cylinder temperature, which gives HCCI improved efficiency and reduces NOx formation. To initiate HCCI with a typical compression ratio, the sensible energy of the mixture needs to be high compared to a spark ignited (SI) strategy. One approach to achieve this, called recompression HCCI, is by closing the exhaust valve early to trap a portion of the exhaust gas in the cylinder. Unlike a SI or Diesel strategy, HCCI lacks an explicit combustion trigger, as autoignition is governed by chemical kinetics. Therefore, the thermo-chemical conditions of the air-fuel mixture need to be carefully controlled for HCCI to occur at the desired timing. Compounding this challenge in recompression HCCI is the re-utilization of the exhaust gas which creates cycle-to-cycle coupling. Furthermore, the coupling characteristics can change drastically around different operating points, making combustion timing control difficult across a wide range of conditions. In this thesis, a graphical analysis examines the in-cylinder temperature dynamics of recompression HCCI and reveals three qualitative types of temperature dynamics. With this insight, a switching linear model is formulated by combining three linear models: one for each of the three types of temperature dynamics. A switching controller that is composed of three local linear feedback controllers can then be designed based on the switching model. This switching model/control formulation is tested on an experimental HCCI testbed and shows good performance in controlling the combustion timing across a wide range. A semi-definite program is formulated to find a Lyapunov function for the switching model/control framework and shows that it is stable. As HCCI is dictated by the in-cylinder thermo-chemical conditions, there are further concerns about the robustness of HCCI, i.e., the boundedness of the thermo-chemical conditions with uncertainty existing in the ambient conditions and in the engine's own characteristics due to aging. To assess HCCI's robustness, this thesis presents a linear parameter varying (LPV) model that captures the dynamics of recompression HCCI and possesses an elegant model structure that is more amenable to analysis. Based on this model, a recursive algorithm using convex optimization is formulated to generate analytical statements about the boundedness of the in-cylinder thermo-chemical conditions. The bounds generated by the algorithm are also shown to relate well to the data from the experimental testbed.

Hcci and Cai Engines for the Automotive Industry

Download Hcci and Cai Engines for the Automotive Industry PDF Online Free

Author :
Publisher : Elsevier
ISBN 13 : 184569354X
Total Pages : 557 pages
Book Rating : 4.8/5 (456 download)

DOWNLOAD NOW!


Book Synopsis Hcci and Cai Engines for the Automotive Industry by : H Zhao

Download or read book Hcci and Cai Engines for the Automotive Industry written by H Zhao and published by Elsevier. This book was released on 2007-08-02 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous charge compression ignition (HCCI)/controlled auto-ignition (CAI) has emerged as one of the most promising engine technologies with the potential to combine fuel efficiency and improved emissions performance, offering reduced nitrous oxides and particulate matter alongside efficiency comparable with modern diesel engines. Despite the considerable advantages, its operational range is rather limited and controlling the combustion (timing of ignition and rate of energy release) is still an area of on-going research. Commercial applications are, however, close to reality.HCCI and CAI engines for the automotive industry presents the state-of-the-art in research and development on an international basis, as a one-stop reference work. The background to the development of HCCI / CAI engine technology is described. Basic principles, the technologies and their potential applications, strengths and weaknesses, as well as likely future trends and sources of further information are reviewed in the areas of gasoline HCCI / CAI engines; diesel HCCI engines; HCCI / CAI engines with alternative fuels; and advanced modelling and experimental techniques. The book provides an invaluable source of information for scientific researchers, R&D engineers and managers in the automotive engineering industry worldwide. Presents the state-of-the-art in research and development on an international basis An invaluable source of information for scientific researchers, R&D engineers and managers in the automotive engineering industry worldwide Looks at one of the most promising engine technologies around

Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller

Download Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (813 download)

DOWNLOAD NOW!


Book Synopsis Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller by : Marwa Abdelgawad

Download or read book Combustion Timing Control of Natural Gas HCCI Engines Using Physics-based Modeling and LQR Controller written by Marwa Abdelgawad and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Homogeneous Charge Compression Ignition (HCCI) Engines hold promises of being the next generation of internal combustion engines due to their ability to produce high thermal efficiencies and low emission levels. HCCI combustion is achieved through the auto-ignition of a compressed homogenous fuel-air mixture, thus making it a "fusion" between spark-ignition and compression-ignition engines. The main challenge in developing HCCI engines is the absence of a combustion trigger hence making it difficult to control its combustion timing. The aim of this research project is to model and control a natural gas HCCI engine. Since HCCI depends primarily on temperature and chemical composition of the mixture, Exhaust Gas Recirculation (EGR) is used to control ignition timing. In this research, a thermodynamical, physics-based nonlinear model is developed to capture the main features of the HCCI engine. In addition, the Modified Knock Integral Model (MKIM), used to predict ignition timing, is optimized. To validate the nonlinear model, ignition timing under varying conditions using the MKIM approach is shown to be in accordance with data acquired from a model developed using a sophisticated engine simulation program, GT-Power. Most control strategies are based on a linear model, therefore, the nonlinear model is linearized using the perturbation method. The linear model is validated by comparing its performance with the nonlinear model about a suitable operating point. The control of ignition timing can be defined as a regulation process where the goal is to force the nonlinear model to track a desired ignition timing by controlling the EGR ratio. Parameters from the linear model are used to determine the gains of the LQR controller. The performance of the controller is validated by implementing it on the nonlinear model and observing its ability to track the desired timing with 0.5% error within a certain operating range. To increase the operating range of the controller and reduce steady-state error, an integrator is added to the LQR. Finally, it is shown that the LQR controller is able to successfully reject disturbance, parameter variation, as well as noise.

Modelling the Combustion in a Dual Fuel HCCI Engine

Download Modelling the Combustion in a Dual Fuel HCCI Engine PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (16 download)

DOWNLOAD NOW!


Book Synopsis Modelling the Combustion in a Dual Fuel HCCI Engine by : Hossein Ghomashi

Download or read book Modelling the Combustion in a Dual Fuel HCCI Engine written by Hossein Ghomashi and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Design of a Viable Homogeneous-charge Compression-ignition (HCCI) Engine

Download Design of a Viable Homogeneous-charge Compression-ignition (HCCI) Engine PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 261 pages
Book Rating : 4.:/5 (63 download)

DOWNLOAD NOW!


Book Synopsis Design of a Viable Homogeneous-charge Compression-ignition (HCCI) Engine by : Paul E. Yelvington

Download or read book Design of a Viable Homogeneous-charge Compression-ignition (HCCI) Engine written by Paul E. Yelvington and published by . This book was released on 2004 with total page 261 pages. Available in PDF, EPUB and Kindle. Book excerpt: The homogeneous-charge compression-ignition (HCCI) engine is a novel engine technology with the potential to substantially lower emissions from automotive sources. HCCI engines use lean-premixed combustion to achieve good fuel economy and low emissions of nitrogen-oxides and particulate matter. However, experimentally these engines have demonstrated a viable operating range that is too narrow for vehicular applications. Incomplete combustion or misfire can occur under fuel-lean conditions imposing a minimum load at which the engine can operate. At high loads, HCCI engines are often extremely loud and measured cylinder pressures show strong acoustic oscillations resembling those for a knocking sparkignited engine. The goal of this research was to understand the factors limiting the HCCI range of operability and propose ways of broadening that range. An engine simulation tool was developed to model the combustion process in the engine and predict HCCI knock and incomplete combustion. Predicting HCCI engine knock is particularly important because knock limits the maximum engine torque, and this limitation is a major obstacle to commercialization. A fundamentally-based criterion was developed and shown to give good predictions of the experimental knock limit. Our engine simulation tool was then used to explore the effect of various engine design parameters and operating conditions on the HCCI viable operating range. Performance maps, which show the response of the engine during a normal driving cycle, were constructed to compare these engine designs. The simulations showed that an acceptably broad operating range can be achieved by using a low compression ratio, low octane fuel, and moderate boost pressure. An explanation of why this choice of parameters gives a broad operating window is discussed. Our prediction of the HCCI knock limit is based on the autoignition theory of knock, which asserts that local overpressures in the engine are caused by extremely rapid chemical energy release. A competing theory asserts that knock is caused by the formation of detonation waves initiated at autoignition centers ('hot-spots') in the engine. No conclusive experimental evidence exists for the detonation theory, but many numerical simulations in the literature show that detonation formation is possible; however, some of the assumptions made in these simulations warrant re-examination. In particular, the effect of curvature on small (quasispherical) hot-spots has often been overlooked. We first examined the well-studied case of gasoline spark-ignited engine knock and observed that the size of the hot-spot needed to initiate a detonation is larger than the end-gas region where knock occurs. Subsequent studies of HCCI engine knock predicted that detonations would not form regardless of the hot-spot size because of the low energy content of fuel-lean mixtures typically used in these engines. Our predictions of the HCCI viable operating range were shown to be quite sensitive to details of the ignition chemistry. Therefore, an attempt was made to build an improved chemistry model for HCCI combustion using automatic mechanism-generation software developed in our research group. Extensions to the software were made to allow chemistry model construction for engine conditions. Model predictions for n-heptane/air combustion were compared to literature data from a jet-stirred reactor and rapid-compression machine. We conclude that automatic mechanism generation gives fair predictions without the tuning of rate parameters or other efforts to improve agreement. However, some tuning of the automatically-generated chemistry models is necessary to give the accurate predictions of HCCI combustion needed for our design calculations.

Recent Technologies for Enhancing Performance and Reducing Emissions in Diesel Engines

Download Recent Technologies for Enhancing Performance and Reducing Emissions in Diesel Engines PDF Online Free

Author :
Publisher : IGI Global
ISBN 13 : 1799825418
Total Pages : 298 pages
Book Rating : 4.7/5 (998 download)

DOWNLOAD NOW!


Book Synopsis Recent Technologies for Enhancing Performance and Reducing Emissions in Diesel Engines by : Basha, J. Sadhik

Download or read book Recent Technologies for Enhancing Performance and Reducing Emissions in Diesel Engines written by Basha, J. Sadhik and published by IGI Global. This book was released on 2020-02-21 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: In today’s global context, there has been extensive research conducted in reducing harmful emissions to conserve and protect our environment. In the automobile and power generation industries, diesel engines are being utilized due to their high level of performance and fuel economy. However, these engines are producing harmful pollutants that contribute to several global threats including greenhouse gases and ozone layer depletion. Professionals have begun developing techniques to improve the performance and reduce emissions of diesel engines, but significant research is lacking in this area. Recent Technologies for Enhancing Performance and Reducing Emissions in Diesel Engines is a pivotal reference source that provides vital research on technical and environmental enhancements to the emission and combustion characteristics of diesel engines. While highlighting topics such as biodiesel emulsions, nanoparticle additives, and mathematical modeling, this publication explores the potential additives that have been incorporated into the performance of diesel engines in order to positively affect the environment. This book is ideally designed for chemical and electrical engineers, developers, researchers, power generation professionals, mechanical practitioners, scholars, ecologists, scientists, graduate students, and academicians seeking current research on modern innovations in fuel processing and environmental pollution control.

Assessment of Fuel Economy Technologies for Light-Duty Vehicles

Download Assessment of Fuel Economy Technologies for Light-Duty Vehicles PDF Online Free

Author :
Publisher : National Academies Press
ISBN 13 : 0309216389
Total Pages : 373 pages
Book Rating : 4.3/5 (92 download)

DOWNLOAD NOW!


Book Synopsis Assessment of Fuel Economy Technologies for Light-Duty Vehicles by : National Research Council

Download or read book Assessment of Fuel Economy Technologies for Light-Duty Vehicles written by National Research Council and published by National Academies Press. This book was released on 2011-06-03 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various combinations of commercially available technologies could greatly reduce fuel consumption in passenger cars, sport-utility vehicles, minivans, and other light-duty vehicles without compromising vehicle performance or safety. Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy estimates the potential fuel savings and costs to consumers of available technology combinations for three types of engines: spark-ignition gasoline, compression-ignition diesel, and hybrid. According to its estimates, adopting the full combination of improved technologies in medium and large cars and pickup trucks with spark-ignition engines could reduce fuel consumption by 29 percent at an additional cost of $2,200 to the consumer. Replacing spark-ignition engines with diesel engines and components would yield fuel savings of about 37 percent at an added cost of approximately $5,900 per vehicle, and replacing spark-ignition engines with hybrid engines and components would reduce fuel consumption by 43 percent at an increase of $6,000 per vehicle. The book focuses on fuel consumption-the amount of fuel consumed in a given driving distance-because energy savings are directly related to the amount of fuel used. In contrast, fuel economy measures how far a vehicle will travel with a gallon of fuel. Because fuel consumption data indicate money saved on fuel purchases and reductions in carbon dioxide emissions, the book finds that vehicle stickers should provide consumers with fuel consumption data in addition to fuel economy information.

Advances in Internal Combustion Engine Research

Download Advances in Internal Combustion Engine Research PDF Online Free

Author :
Publisher : Springer
ISBN 13 : 9811075751
Total Pages : 346 pages
Book Rating : 4.8/5 (11 download)

DOWNLOAD NOW!


Book Synopsis Advances in Internal Combustion Engine Research by : Dhananjay Kumar Srivastava

Download or read book Advances in Internal Combustion Engine Research written by Dhananjay Kumar Srivastava and published by Springer. This book was released on 2017-11-29 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book discusses all aspects of advanced engine technologies, and describes the role of alternative fuels and solution-based modeling studies in meeting the increasingly higher standards of the automotive industry. By promoting research into more efficient and environment-friendly combustion technologies, it helps enable researchers to develop higher-power engines with lower fuel consumption, emissions, and noise levels. Over the course of 12 chapters, it covers research in areas such as homogeneous charge compression ignition (HCCI) combustion and control strategies, the use of alternative fuels and additives in combination with new combustion technology and novel approaches to recover the pumping loss in the spark ignition engine. The book will serve as a valuable resource for academic researchers and professional automotive engineers alike.

Modelling the Combustion in a Duel Fuel HCCI Engine

Download Modelling the Combustion in a Duel Fuel HCCI Engine PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 205 pages
Book Rating : 4.:/5 (117 download)

DOWNLOAD NOW!


Book Synopsis Modelling the Combustion in a Duel Fuel HCCI Engine by : Hossein Ghomashi

Download or read book Modelling the Combustion in a Duel Fuel HCCI Engine written by Hossein Ghomashi and published by . This book was released on 2013 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt: