Download or read book Model and Igniter Development for Plasma Assisted Combustion written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent progress on the authors' efforts to develop a detailed kinetic mechanism for C(sub 8)H(sub m) hydrocarbons and practical plasma igniters for plasma-assisted combustion are discussed. Shock tube validation experiments made in argon using a fixed stoichiometry (PHI = 1.0), pressures of approximately 0.95 and 1.05 atm, and temperatures ranging from 850 to 1200 K (post-reflected shock) are presented. The mechanism is being expanded to include electron kinetics and to allow for a degree of nonequilibrium modeled with separate electron and gas temperatures. Quantum calculations used to derive needed electron impact ionization/dissociation cross-sections for hydrocarbons are discussed. In addition, ignition of ethylene fuel in a Mach 2 supersonic flow with a total temperature of 590 K and pressure of 5.4 atm is demonstrated using a low frequency discharge with peak and average powers reaching 8 kW and 2.8 kW, respectively. (7 figures, 28 refs.).

Download or read book Plasma Assisted Combustion Gasification and Pollution Control written by Igor Matveev and published by . This book was released on 2015-12-14 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume book is one of the first projects of the newly established International Plasma Technology Center (IPTC) and is the first attempt to collect the most valuable contributions to the relatively new field of science named Plasma Assisted Combustion (PAC) from different research groups all over the globe. It provides in Volume 1 a description of different plasma sources especially designed for PAC and, in Volume 2, describes plasma assisted ignition, combustion, and gasification processes that are under development or used industrially. If successful, we plan to publish new editions every three to five years, depending on progress in this field. This book is intended to be used as a textbook at the senior or first-year graduate level by students from all engineering and physical science disciplines, by PhD students, and as a reference source by in-service engineers and other researchers. Basic information on plasma physics and accompanying physical processes important in PAC are contained in Volume 1. Devices, technologies, current state, and future works are covered in Volume 2.

Download or read book Aeronautics and Astronautics written by Max Mulder and published by IntechOpen. This book was released on 2011-09-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In its first centennial, aerospace has matured from a pioneering activity to an indispensable enabler of our daily life activities. In the next twenty to thirty years, aerospace will face a tremendous challenge - the development of flying objects that do not depend on fossil fuels. The twenty-three chapters in this book capture some of the new technologies and methods that are currently being developed to enable sustainable air transport and space flight. It clearly illustrates the multi-disciplinary character of aerospace engineering, and the fact that the challenges of air transportation and space missions continue to call for the most innovative solutions and daring concepts.

Download or read book Development and Application of a High performance Framework for High fidelity Simulations of Plasma assisted Ignition of Hydrocarbon Fuels Using Nanosecond Pulsed Discharges written by Nicholas E. Deak and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The application of non-equilibrium plasma (NEP) pulses to ignite hydrocarbon/air mixtures has emerged as a promising technology for ensuring reliable ignition and combustion stability in difficult regimes. Despite its promise, major challenges and limitations still remain, particularly in the realm of conducting high-fidelity multidimensional numerical studies. The aim of this thesis is to develop, implement, and apply a robust and efficient computational framework that addresses some of these shortcomings. As a preliminary step, the ignition of hydrocarbon/air mixtures by nanosecond pulsed discharges (NSPD) is investigated using a zero dimensional isochoric adiabatic reactor. A state-of-the-art two-temperature kinetics model, comprised of an experimentally-verified NEP plasma mechanism coupled with a hydrocarbon/air oxidation mechanism, is used. Simulations are performed to assess the impact of changing initial pressure (which varies from 1 to 30 atm) and fuel type (methane and ethylene). It is found that at lower pressures, plasma-assisted ignition (PAI) imparts a benefit over thermal ignition for both fuel types, through the creation of combustion radicals O, H, and OH. At higher pressures, PAI of methane loses efficiency compared to ethylene, due to a lack of available H radicals (which are swept up by O2), which limits the conversion of formaldehyde to formyl. Next, a robust and efficient framework for simulating NSPD in multiple dimensions is developed. The reactive Navier-Stokes equations are extended to include a drift-diffusion plasma-fluid model with a local field approximation (LFA) in a finite-volume solver, which uses an adaptive mesh refinement (AMR) strategy to address the wide separation of length scales in the problem. A two-way coupling strategy is used whereby the plasma-fluid model and reactive Navier-Stokes equations are integrated simultaneously. An effective grid refinement approach is developed in order to ensure that the physical structures that arise during and after the NSD (including the propagating streamer heads, electrode sheaths, and expansion wave during the inter-pulse period) are resolved efficiently. Severe time step size restrictions that arise from the explicit temporal integration of the transport terms are mitigated through use of a semi-implicit approach for solving Poisson's equation for the electric potential, and an implicit strategy for evaluating electron diffusion terms. A series of numerical studies are then conducted to investigate the ignition and propagation phases of atmospheric air streamers in axisymmetric discharge configurations. A range of conditions and configurations are explored to characterize the streamer, with an emphasis on the cathode sheath region, which supports steep gradients in charged species number densities as well as strong electric fields. The formation of the cathode sheath is shown to be a consequence of processes at the cathode surface, driven by electron losses at the boundary, and a strong dependence on the emission of secondary electrons. Finally, the oxidation of ethylene/air mixtures mediated by NSPD is simulated in a pin-to-pin configuration. All phases of the plasma discharge are simulated explicitly (including streamer ignition, propagation, and connection, as well as the subsequent spark phase), along with the evolution of the plasma during the inter-pulse period. Temporally and spatially-resolved results are presented, with an emphasis on the analysis of heating and energy deposition, as well as of the evolution of the concentration of active particles generated during the NSPD and their influence on ignition. The impact of pin thickness is discussed, and it is shown that the use of thin pins limits the regions of energy deposition and temperature increase near the pin tips, hindering ignition. The application of multiple pulses is explored and it is shown that multiple voltage pulses of the same strength leads to substantial energy deposition and temperature increases O(1,000 - 10,000 K) near the pin tips. Discussion is rounded out by addressing how pulse frequency and initial mixture control the generation of active particles and combustion products. Finally, recommendations for future work are provided

Download or read book Plasma Kinetics in Atmospheric Gases written by M. Capitelli and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt: Emphasis is placed on the analysis of translational, rotational, vibrational and electronically excited state kinetics, coupled to the electron Boltzmann equation.

Download or read book Kinetic Modeling and Sensitivity Analysis of Plasma assisted Combustion written by Kuninori Togai and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma-assisted combustion (PAC) is a promising combustion enhancement technique that shows great potential for applications to a number of different practical combustion systems. In this dissertation, the chemical kinetics associated with PAC are investigated numerically with a newly developed model that describes the chemical processes induced by plasma. To support the model development, experiments were performed using a plasma flow reactor in which the fuel oxidation proceeds with the aid of plasma discharges below and above the self-ignition thermal limit of the reactive mixtures. The mixtures used were heavily diluted with Ar in order to study the reactions with temperature-controlled environments by suppressing the temperature changes due to chemical reactions. The temperature of the reactor was varied from 420 K to 1250 K and the pressure was fixed at 1 atm. Simulations were performed for the conditions corresponding to the experiments and the results are compared against each other. Important reaction paths were identified through path flux and sensitivity analyses. Reaction systems studied in this work are oxidation of hydrogen, ethylene, and methane, as well as the kinetics of NOx in plasma.In the fuel oxidation studies, reaction schemes that control the fuel oxidation are analyzed and discussed. With all the fuels studied, the oxidation reactions were extended to lower temperatures with plasma discharges compared to the cases without plasma. The analyses showed that radicals produced by dissociation of the reactants in plasma plays an important role of initiating the reaction sequence. At low temperatures where the system exhibits a chain-terminating nature, reactions of HO2 were found to play important roles on overall fuel oxidation. The effectiveness of HO2 as a chain terminator was weakened in the ethylene oxidation system, because the reactions of C2H4 + O that have low activation energies deflects the flux of O atoms away from HO2. For the ethylene and methane oxidation systems, the reaction pathways important for the formation of intermediate species are discussed. The reactions of CH3 and C2H5 were found to influence the production channels of minor species.In the studies on the kinetics of NOx in plasma, several mechanistic insights were obtained, including the identification of formation and consumption steps of N2O and the extensive review of three NO formation schemes found in the current reaction mechanism. Efforts to address the known inaccuracies of the current model are also reported.

Download or read book Plasma Assisted Combustion Gasification and Pollution Control written by Igor Matveev and published by . This book was released on 2013-06 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: Provides a description of different plasma sources especially designed for Plasma Assisted Combustion.

Download or read book Plasma Induced Ignition and Plasma Assisted Combustion in High Speed Flow written by and published by . This book was released on 2003 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper is dedicated to the experimental demonstration of plasma technology abilities in the field of high speed combustion. It is doing in three principal directions: control of the structure and the parameters of the duct driven flows; the ignition of air fuel composition at low mean gas temperature; and the mixing intensification inflow.

Download or read book Molecular Physics and Hypersonic Flows written by M. Capitelli and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Physics and Hypersonic Flows bridges the gap between the fluid dynamics and molecular physics communities, emphasizing the role played by elementary processes in hypersonic flows. In particular, the work is primarily dedicated to filling the gap between microscopic and macroscopic treatments of the source terms to be inserted in the fluid dynamics codes. The first part of the book describes the molecular dynamics of elementary processes both in the gas phase and in the interaction with surfaces by using quantum mechanical and phenomenological approaches. A second group of contributions describes thermodynamics and transport properties of air components, with special attention to the transport of internal energy. A series of papers is devoted to the experimental and theoretical study of the flow of partially ionized gases. Subsequent contributions treat modern computational techniques for 3-D hypersonic flow. Non-equilibrium vibrational kinetics are then described, together with the coupling of vibration-dissociation processes as they affect hypersonic flows. Special emphasis is given to the interfacing of non-equilibrium models with computational fluid dynamics methods. Finally, the last part of the book deals with the application of direct Monte Carlo methods in describing rarefied flows.

Download or read book RF Power Semiconductor Generator Application in Heating and Energy Utilization written by Satoshi Horikoshi and published by Springer Nature. This book was released on 2020-03-26 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a specialized book for researchers and technicians of universities and companies who are interested in the fundamentals of RF power semiconductors, their applications and market penetration.Looking around, we see that products using vacuum tube technology are disappearing. For example, branch tube TVs have changed to liquid crystal TVs, and fluorescent light have turned into LED. The switch from vacuum tube technology to semiconductor technology has progressed remarkably. At the same time, high-precision functionalization, miniaturization and energy saving have advanced. On the other hand, there is a magnetron which is a vacuum tube device for generating microwaves. However, even this vacuum tube technology has come to be replaced by RF power semiconductor technology. In the last few years the price of semiconductors has dropped sharply and its application to microwave heating and energy fields will proceed. In some fields the transition from magnetron microwave oscillator to semiconductor microwave oscillator has already begun. From now on this development will progress remarkably. Although there are several technical books on electrical systems that explain RF power semiconductors, there are no books yet based on users' viewpoints on actual microwave heating and energy fields. In particular, none have been written about exact usage and practical cases, to answer questions such as "What are the advantages and disadvantages of RF power semiconductor oscillator?", "What kind of field can be used?" and the difficulty of the market and application. Based on these issues, this book explains the RF power semiconductors from the user's point of view by covering a very wide range of fields.

Download or read book Plasma Processes for Renewable Energy Technologies written by Masaaki Okubo and published by MDPI. This book was released on 2020-01-07 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of renewable energy is an effective solution for the prevention of global warming. On the other hand, environmental plasmas are one of powerful means to solve global environmental problems on nitrogen oxides, (NOx), sulfur oxides (SOx), particulate matter (PM), volatile organic compounds (VOC), and carbon dioxides (CO2) in the atmosphere. By combining both technologies, we can develop an extremely effective environmental improvement technology. Based on this background, a Special Issue of the journal Energies on plasma processes for renewable energy technologies is planned. On the issue, we focus on environment plasma technologies that can effectively utilize renewable electric energy sources, such as photovoltaic power generation, biofuel power generation, wind turbine power generation, etc. However, any latest research results on plasma environmental improvement processes are welcome for submission. We are looking, among others, for papers on the following technical subjects in which either plasma can use renewable energy sources or can be used for renewable energy technologies: · Plasma decomposition technology of harmful gases, such as the plasma denitrification method; · Plasma removal technology of harmful particles, such as electrostatic precipitation; · Plasma decomposition technology of harmful substances in liquid, such as gas–liquid interfacial plasma; · Plasma-enhanced flow induction and heat transfer enhancement technologies, such as ionic wind device and plasma actuator; · Plasma-enhanced combustion and fuel reforming; · Other environment plasma technologies.

Download or read book Plasma assisted Combustion written by Timothy M. Ombrello and published by . This book was released on 2009 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Mechanism of Combustion written by J. T. Anthony and published by . This book was released on 1918 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plasma Science and Technology written by Haikel Jelassi and published by BoD – Books on Demand. This book was released on 2019-02-27 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Usually called the "fourth state of matter," plasmas make up more than 99% of known material. In usual terminology, this term generally refers to partially or totally ionized gas and covers a large number of topics with very different characteristics and behaviors. Over the last few decades, the physics and engineering of plasmas was experiencing a renewed interest, essentially born of a series of important applications such as thin-layer deposition, surface treatment, isotopic separation, integrated circuit etchings, medicine, etc. Plasma Science

Download or read book Modeling of Plasma Induced Ignition and Combustion written by and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrothermal-chemical (ETC) ignition systems have been demonstrated in gun systems to provide desirable characteristics including reproducible shorter ignition delays. We present a combined theoretical and experimental study of the capillary discharge with an aim to develop a capillary plasma source with efficient energy conversion. In addition, a detailed understanding of the dynamics of the plasma-propellant interaction is considered one of the key elements to the future success of practical ETC gun implementation. We address this issue by developing a model of the propellant ablation under plasma effect based on the kinetic theory of ablation. The major emphasis in the present capillary discharge model is the ablation phenomenon. A kinetic approach is used to determine the parameters at the interface between the kinetic Knudsen layer and the hydrodynamic layer. In parallel, a parametric experimental study of the capillary ablation process is conducted at Army Research Laboratory. Both experimental measurements and simulations indicate that the ablated mass increases with the peak discharge current and that a smaller diameter capillary yields a larger ablated mass. It is found that model predictions agree well with experimental measurements. The ablation model is coupled with a model of the plasma generation in the capillary discharge that allows calculation of the effective heat flux from the plasma. Calculations are performed for specific experimental conditions in which ablated mass of a double-base and a nitramine composite propellant are studied. One representative solution reproduces the experimentally determined ablated mass for the double-base propellant of 5.3 mg via an effective heat flux on the order of 4x10(exp 8) J/m squared s. The effective heat flux that corresponds to the experimentally measured ablated mass is determined for different propellants.

Download or read book Pulsed Plasma Generator Development and Low temperature Plasma assisted Combustion at Atmospheric Pressure written by Mathew Evans and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "This thesis presents an experimental study of the engineering and physics of high-voltage nanosecond-pulsed diffuse discharges, and their application to the enhancement of lean-premixed combustion at atmospheric pressure. The technology development in this work is focused on providing appropriate low-temperature radical pools, and the experiments are aimed at demonstrating the effect of these pools for combustion actuation. The experimental results are focused on the explanation of the physical processes associated with these discharges. The discharge propagation and emission spectrum were examined, the distribution functions of particles along internal energy levels were calculated, and the resulting enhancement of combustion was observed. This work shows that the plasma emission from fuel-lean mixtures is primarily composed of high vibrational populations of electronically excited nitrogen molecules, upon which a low-temperature is measured on the rotational manifold. Previous work shows that these low-temperature excited particles will collide with molecular oxygen, or fuel molecules, to produce species (atomic/molecular ground/excited oxygen, fragmented fuel molecules...) that accelerate chain-branching reactions in the combustion reaction mechanism. This work shows that the majority of the electronically excited vibrational states of nitrogen molecules, in a diffuse discharge, decay rapidly after the application of a high-voltage pulse. These findings set the framework for the implementation of diffuse plasma to laboratory-scale combustion enhancement. As an integral part of this work, the design and development of electrical generators that can produce such a reactive medium in large volume is included, and extensively detailed. An inexpensive solid-state pulse generator, based on commercially available amorphous ferromagnetic materials, is designed and developed to drive capacitive loads. The generator is used to produce large volumes of diffuse plasma and increase the blow off velocity of stagnation flames. To further investigate this enhancement, an optically accessible plasma burner is implemented and used for the detailed study of stagnation flame plasma actuation. This work shows that significant actuation can be provided to a flame, when diffuse plasma is placed upstream, and directly in contact with the combustion front. The displacement of the leading edge of a flame, into the fresh unburned mixture, is measured following a high-voltage actuating pulse. The displacement of the leading edge strongly points toward low-temperature reactivity enhancement. The optical and electrical characteristics of the diffuse plasma are reported for both the non-combusting and combusting flows. These provide a more accurate picture of the thermal characteristics and complex phenomena occurring in this transient discharge. Streamer propagation dynamics and coupled energy measurements are reported to provide further insight regarding the delicate balance that exists between plasma and flame sheet in this experimental configuration. It can be concluded that diffuse plasma is an effective low-temperature chemical actuation method for combustion enhancement at atmospheric pressure.To conclude this work, the first step toward high-pressure actuation of combustion with diffuse plasma was explored. The task of producing diffuse plasma above atmospheric pressure was undertaken. This work presents the development of a second solid-state pulse generator with increased power delivery capabilities. The generator is used to produce large volumes of diffuse plasma in a high-pressure vessel filled with air. It is found that diffuse plasma actuation could eventually be implemented in a high-pressure combustion experiment using this technology." --

Download or read book Ignition Systems for Gasoline Engines written by Michael Günther and published by Springer. This book was released on 2016-11-18 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: The volume includes selected and reviewed papers from the 3rd Conference on Ignition Systems for Gasoline Engines in Berlin in November 2016. Experts from industry and universities discuss in their papers the challenges to ignition systems in providing reliable, precise ignition in the light of a wide spread in mixture quality, high exhaust gas recirculation rates and high cylinder pressures. Classic spark plug ignition as well as alternative ignition systems are assessed, the ignition system being one of the key technologies to further optimizing the gasoline engine.