Download or read book Flame Propagation in Natural Gas Fueled Direct Injection Engines microform written by Mark A. (Mark Adam) Fabbroni and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2004 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Natural gas has shown promise as an alternative fuel for diesel engines. Research has shown that natural gas requires assistance to ignite in a diesel engine chamber. This results in a single site of ignition from which the flame must propagate to other jets in the injection pattern. The goal of this work was to determine what factors affect how the flame propagates from this initial ignition site to the remaining unburned mixture. The combustion of natural gas jets under diesel engine conditions was studied over a range of temperatures, pressures, equivalence ratios, and glow plug shield designs using a rapid compression device. Ignition was provided by a shielded glow plug. The results show that of all the factors considered the geometry of the injection pattern, chamber, and glow plug shield are most dominant in controlling combustion rates and efficiency.
Download or read book Advances in Compression Ignition Natural Gas Diesel Dual Fuel Engines written by Hongsheng Guo and published by Frontiers Media SA. This book was released on 2021-03-23 with total page 125 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Prechambers on Flame Propagation in a Natural gas Powered Engine written by and published by . This book was released on 1995 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large-bore two-stroke natural-gas-fueled engines commonly are located along natural gas pipelines, siphoning off a small portion of gas from the pipeline for use as a fuel, in order to pump the remaining gas along the pipeline. The KIVA-3 computational fluid dynamics program was used to simulate the compression stroke, combustion, and power stroke in a natural-gas-fueled engine by solving the full Navier-Stokes equations. These calculations include cases with and without prechambers. Prechamber stoichiometry and spark locations were independently varied with the goal of understanding how various prechamber parameters influence the ignition of the fuel-air charge in the main chamber. The goal is to allow the use of very lean main-chamber charges to minimize nitrogen oxide (NO(subscript x)) production. These calculations were performed in both two and three dimensions.
Download or read book Investigation of Preflame Reactions and Flame Propagation in Direct Injection Diesel Enginees written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: It was to investigate (invisible) preflame reactions taking place in a direct-injection compression ignition (DI-CI) engine during the ignition delay period and their effects on subsequent (visible) combustion reactions. The investigation was focused on the subject for an engine equipped with a high-pressure injection (HPI) unit in order to support the development of high-power-output Diesel engines. The use of HPZ was found to facilitate more air utilization in a DI-CI engine even operated with intake air at unusually high temperatures (e.g., encountered in uncooled engines). In order to achieve these goals, several new research methods were developed-advanced for the study, including Rutgers or Super Imaging System (SIS), spectrometric methods, and Rutgers Animation Program. The tools were employed on an optical single-cylinder Cummins 903 engine. Among the significant results in system development is that the basic methods for high-speed imaging achievable at consecutive cycles, which shed some new insight into complex in-cylinder phenomena. The new research methods developed under the present ARO study permits observation of timed global pictures of preflame propagation under various engine-fuel conditions. New findings of the study include that the fuel injected into the cylinder immediately commences to chemically react, unlike the previous thought that there is a physical delay proceeding actual chemical reactions. The reactions involved during the preflame reactions appear to be low-temperature kinetics controlled processes to affect the onset of visible-ray flame formation and combustion reactions. The preflame reaction species were found rapidly consumed as soon as the heat-releasing flame propagation took place.
Download or read book Multi dimensional Modeling of Natural Gas Ignition Combustion and Pollutant Formation in Direct Injection Engines written by Apoorva Agarwal and published by . This book was released on 1998 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Experimental and Theoretical Investigations of Lean Partially Premixed Combustion Burning Speed Flame Instability and Plasma Formation of Alternative Fuels at High Temperatures and Pressures written by Omid Askari and published by . This book was released on 2016 with total page 271 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation investigates the combustion and injection fundamental characteristics of different alternative fuels both experimentally and theoretically. The subjects such as lean partially premixed combustion of methane/hydrogen/air/diluent, methane high pressure direct-injection, thermal plasma formation, thermodynamic properties of hydrocarbon/air mixtures at high temperatures, laminar flames and flame morphology of synthetic gas (syngas) and Gas-to-Liquid (GTL) fuels were extensively studied in this work. These subjects will be summarized in three following paragraphs. The fundamentals of spray and partially premixed combustion characteristics of directly injected methane in a constant volume combustion chamber have been experimentally studied. The injected fuel jet generates turbulence in the vessel and forms a turbulent heterogeneous fuel-air mixture in the vessel, similar to that in a Compressed Natural Gas (CNG) Direct-Injection (DI) engines. The effect of different characteristics parameters such as spark delay time, stratification ratio, turbulence intensity, fuel injection pressure, chamber pressure, chamber temperature, Exhaust Gas recirculation (EGR) addition, hydrogen addition and equivalence ratio on flame propagation and emission concentrations were analyzed. As a part of this work and for the purpose of control and calibration of high pressure injector, spray development and characteristics including spray tip penetration, spray cone angle and overall equivalence ratio were evaluated under a wide range of fuel injection pressures of 30 to 90 atm and different chamber pressures of 1 to 5 atm. Thermodynamic properties of hydrocarbon/air plasma mixtures at ultra-high temperatures must be precisely calculated due to important influence on the flame kernel formation and propagation in combusting flows and spark discharge applications. A new algorithm based on the statistical thermodynamics was developed to calculate the ultra-high temperature plasma composition and thermodynamic properties. The method was applied to compute the thermodynamic properties of hydrogen/air and methane/air plasma mixtures for a wide range of temperatures (1,000-100,000 K), pressures (10−6-100 atm) and different equivalence ratios within flammability limit. In calculating the individual thermodynamic properties of the atomic species, the Debye-Huckel cutoff criterion has been used for terminating the series expression of the electronic partition function. A new differential-based multi-shell model was developed in conjunction with Schlieren photography to measure laminar burning speed and to study the flame instabilities for different alternative fuels such as syngas and GTL. Flame instabilities such as cracking and wrinkling were observed during flame propagation and discussed in terms of the hydrodynamic and thermo-diffusive effects. Laminar burning speeds were measured using pressure rise data during flame propagation and power law correlations were developed over a wide range of temperatures, pressures and equivalence ratios. As a part of this work, the effect of EGR addition and substitution of nitrogen with helium in air on flame morphology and laminar burning speed were extensively investigated. The effect of cell formation on flame surface area of syngas fuel in terms of a newly defined parameter called cellularity factor was also evaluated. In addition to that the experimental onset of auto-ignition and theoretical ignition delay times of premixed GTL/air mixture were determined at high pressures and low temperatures over a wide range of equivalence ratios.
Download or read book Modeling Injection and Ignition in Direct Injection Natural Gas Engines written by Xu Jr Cheng and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Preliminary Study of Flame Propagation in a Spark ignition Engine written by Addison May Rothrock and published by . This book was released on 1937 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The N.A.C.A. combustion apparatus was altered to operate as a fuel-injection, spark-ignition engine, and a preliminary study was made of the combustion of gasoline-air mixtures at various air-fuel ratios. Air-fuel ratios ranging from 10 to 21.6 were investigated. Records from an optical indicator and films from a high-speed motion-picture camera were the chief sources of data. Schlieren photography was used for an additional study.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical and Experimental Study of Flame Propagation and Knock in a Compressed Natural Gas Engine written by Christian Lämmle and published by . This book was released on 2005 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonsteady Flame Propagation written by George H. Markstein and published by Elsevier. This book was released on 2014-12-02 with total page 339 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nonsteady Flame Propagation provides information pertinent to flame propagation in gaseous media. This book focuses on linearized treatments and the comparison of their results with experimental observations. Organized into nine chapters, this book begins with an overview of the challenge of nonlinear problems and examines the essentially nonlinear character of the flame phenomena, which has been artificially suppressed in analyses by the use of linearized perturbation treatments. This text then summarizes the development regarding rocket-shaped burners. Other chapters consider the advantages as well as the limitations of linearized analyses. This book discusses as well a general treatment of the discontinuous-flame-front model and summarizes the results of studies of burner that use secondary air. The final chapter deals with re-examining the possibilities of using pulsating combustion in propulsion or in other applications. This book is a valuable resource for chemical engineers, chemists, scientists, and research workers.
Download or read book Ignition and Flame Propagation in an Engine Cylinder with General Fuel air Mixture Swirl written by John Claude Boutet and published by . This book was released on 1969 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Multi dimensional Modeling of Ignition and Combustion in Premixed and DIS CI direct Injection Spark compression Ignition Engines written by Zhichao Tan and published by . This book was released on 2003 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Autoignition and Emission Characteristics of Gaseous Fuel Direct injection Compression ignition Combustion written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Heavy-duty natural gas engines offer air pollution and energy diversity benefits. However, current homogeneous-charge lean-burn engines suffer from impaired efficiency and high unburned fuel emissions. Natural gas direct-injection engines offer the potential of diesel-like efficiencies, but require further research. To improve understanding of the autoignition and emission characteristics of natural gas direct-injection compression-ignition combustion, the effects of key operating parameters (including injection pressure, injection duration, and pre-combustion temperature) and gaseous fuel composition(including the effects of ethane, hydrogen and nitrogen addition) were studied. An experimental investigation was carried out on a shock tube facility. Ignition delay, ignition kernel location, and NOx emissions were measured. The results indicated that the addition of ethane to the fuel resulted in a decrease in ignition delay and a significant increase in NOx emissions. The addition of hydrogen to the fuel resulted in a decrease in ignition delay and a significant decrease in NOx emissions. Diluting the fuel with nitrogen resulted in an increase in ignition delay and a significant decrease in NOx emissions. Increasing pre-combustion temperature resulted in a significant reduction in ignition delay, and a significant increase in NOx emissions. Modest increase in injection pressure reduced the ignition delay; increasing injection pressure resulted in higher NOx emissions. The effects of ethane, hydrogen, and nitrogen addition on the ignition delay of methane were also successfully predicted by FlameMaster simulation. OH radical distribution in the flame was visualized utilizing Planar Laser Induced Fluorescence (PLIF). Single-shot OH-PLIF images revealed the stochastic nature of the autoignition process of non-premixed methane jets. Examination of the convergence of the ensemble-averaged OH-PLIF images showed that increasing the number of repeat experiments was the most.
Download or read book Multi zone Modelling of Partially Premixed Low temperature Combustion in Pilot ignited Natural gas Engines written by and published by . This book was released on 2010 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed results from a multi-zone phenomenological simulation of partially premixed advanced-injection low-pilot-ignited natural-gas low-temperature combustion are presented with a focus on early injection timings (the beginning of (pilot) injection (BOI)) and very small diesel quantities (2-3 per cent of total fuel energy). Combining several aspects of diesel and spark ignition engine combustion models, the closed-cycle simulation accounted for diesel autoignition, diesel spray combustion, and natural-gas combustion by premixed turbulent flame propagation. The cylinder contents were divided into an unburned zone, several pilot fuel zones (or 'packets') that modelled diesel evaporation and ignition, a flame zone for natural-gas combustion, and a burned zone. The simulation predicted the onset of ignition, cylinder pressures, and heat release rate profiles satisfactorily over a wide range of BOIs (20-60° before top dead centre (before TDC)) but especially well at early BOIs. Strong coupling was observed between pilot spray combustion in the packets and premixed turbulent combustion in the flame zone and, therefore, the number of ignition centres (packets) profoundly affected flame combustion. The highest local peak temperatures (greater than 2000 K) were observed in the packets, while the flame zone was much cooler (about 1650 K), indicating that pilot diesel spray combustion is probably the dominant source of engine-out emissions of nitrogen oxide (NOx). Further, the 60° before TDC BOI yielded the lowest average peak packet temperatures (about 1720 K) compared with the 20° before TDC BOI (about 2480 K) and 40° before TDC BOI (about 2700 K). These trends support experimental NOx trends, which showed the lowest NOx emissions for the 60°, 20°, and 40° before TDC BOIs in that order. Parametric studies showed that increasing the intake charge temperature, pilot quantity, and natural-gas equivalence ratio all led to higher peak heat release rates and hotter packets but the pilot quantity and intake temperature affected the potential for NOx formation to a greater extent.
Download or read book The Influence of In cylinder Flows on the Flame Kernel Growth in Natural Gas Fuelled Spark Ignition Engines microform written by Richard J. Ancimer and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2000 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DING Engine Laboratory for in Cylinder Fuel Air Mixing Studies written by Mark Albert Paul and published by . This book was released on 1997 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
