Download or read book Plasma assisted Combustion in a Supersonic Flow written by Hyungrok Do and published by . This book was released on 2009 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Internal and External Plasma Assisted Combustion in Supersonic Gas Flow written by and published by . This book was released on 2005 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Project is devoted to basic study on the field of external and internal plasma assisted combustion. This effort consists of three Tasks: Task #1 is titled "Internal plasma assisted combustion controlled by improved plasma generators in metal channel at conditions similar to Scramjet"; Task #2 is tilted "External plasma combustion experiment in a supersonic flow (Mtilde2, Pst=1 Bar)". This is a study of flow around model F with plasma combustion generator in wind tunnel; Task #3 is tilted "Study of supersonic flow around model E with combined plasma generator (PG Comb= PG HF +E beam)". Here. the main plasma parameters could be changed independently in PG- Comb. Electron concentration will be controlled by E-beam. Electron temperature could be controlled by external HF electric field. The main goals of this work is a study of following: Optimal radical generation in fuel/air mixture and combustion control by non equilibrium plasmoids, Advanced mixture of fuel in gas flow by structural plasmoids.

Download or read book Plasma Assisted Combustion and Flameholding in High Speed Cavity Flows written by Joseph Aloysius Heinrichs and published by . This book was released on 2012 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: This thesis presents an experimental study of non-equilibrium, low temperature, large volume plasma assisted ignition and flameholding in high-speed, non-premixed fuel-air flows. The plasma is produced between two electrodes powered by a high-voltage, nanosecond pulse generator operated at a high pulse repetition rate. Ignition in this type of plasma occurs due to production of highly reactive radicals by electron impact excitation and dissociation, as opposed to more common thermal ignition. Previously, it has been shown that this type of plasma can reduce ignition delay time and ignition temperature. The experiments performed in this thesis focus on application of these plasmas to ignition, and flameholding in high-speed cavity flows. The experiments discussed in this thesis continue previous work using a high-speed combustion test section with a larger cavity, and the previous results are compared to the present work. Several modifications have been made to the test section and electrodes compared to the design used in previous work in order to reduce the cavity effect on the main flow and maintain diffuse plasma between the electrodes in the cavity. The electrodes used in these experiments are placed in a cavity recess, used to create a recirculation flow region with long residence time, where ignition and flameholding can occur. In order to analyze the nanosecond pulse plasma and the flame, various diagnostics were used, including current and voltage measurements, UV emission measurements, ICCD camera imaging, static pressure measurements, and time-averaged emission spectroscopy. The experiments in this thesis were performed at relatively low pressures (P=150-200 torr) using hydrogen and ethylene fuels injected into the cavity. Current and voltage measurements showed that ~1-2 mJ was coupled to the plasma by each pulse. ICCD imaging and UV emission data revealed that the plasma sustained in quiescent air was diffuse. When ethylene was injected into the cavity to ignite the flow, ICCD imaging and UV emission data showed arcing to bare metal surfaces in the test section occurred shortly after ignition, which prompted switching to hydrogen fuel. Using hydrogen, ICCD imaging and UV emission showed that the plasma remained diffuse and confined to the area between electrodes. Time-average emission spectroscopy measurements revealed that the air-flow temperature remained low until fuel was injected and ignition occurred. Pressure and UV emission measurements were used to find velocity limits within which the flow ignited. It was found that the upper limit of velocity depends strongly on the static pressure in the test section. The highest flow velocity at which combustion was achieved in H2-air flows was 270 m/s at 180 torr. This represents considerable improvement compared to previous work using nanosecond pulse discharge for ignition in cavities. Preliminary results show that plasma generation and ignition are possible using a smaller diameter electrode such that the cavity size can be further reduced, and that a supersonic flow can be produced in the present test section using a Mach 2 nozzle placed upstream of the cavity. The appendix details a study on the production of oxygen atoms using a pulsed excimer laser.

Download or read book Experimental Studies of Plasma assisted Ignition and MHD Supersonic Flow Control written by Rodney Meyer and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Toward Plasma Assisted Ignition in Scramjets written by and published by . This book was released on 2003 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Air Force plasma ignition program is assessing the prospect of main-fuel ignition with plasma generating devices in a supersonic flow. As the study progresses baseline conditions of operation are being established such as the required operational time of the device to initiate a combustion shock train. The two plasma torches currently under investigation consist of a DC constricted-arc design from the Virginia Polytechnic Institute and State University and an AC unconstricted-arc design based on a modified spark-plug from Polytechnic University. The plasma torches are realistic in size and operate within current power constraints while differing substantially in orifice geometry. In order to compare the potential of each concept the flow physics of each part of the igniter/fuel-injector/combustor system are being studied. In each step of the program, we utilize CFD and experiments to help define and advance the ignition process. To understand the constraints involved with ignition process of a hydrocarbon fuel jet an experimental effort to study gaseous and liquid hydrocarbons is underway, involving the testing of ethylene and JP-7 fuels with nitrogen and air plasmas. Results from the individual igniter studies have shown the plasma igniters to produce hot pockets of highly excited gas with peak temperatures up to (and in some cases above) 5000 K at only 2-kW total input power. In addition ethylene and JP-7 flames with a significant level of OH as determined by OH PLIF were also produced in a Mach-2 supersonic flow with a total temperature and pressure of 590 K and 5.4 atm respectively.

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 Microwave Cavity Discharges in a Supersonic Flow written by Dereth Janette Drake and published by LAP Lambert Academic Publishing. This book was released on 2009-09 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Characterization of supersonic flowing discharges (SFD) is important to many applications in aerospace, like plasma-assisted supersonic combustion. In conditions close to the real combustion environment, a cylindrical microwave cavity was used to study the effects of H2 and air admixtures to plasma parameters in an Ar SFD. Ar and H2 were chosen since their atomic and molecular structure are well known. However, the presence of H2, N2, and O2 leads to complex branching inter- radical chemistry, which may result in a decrease in the degree of ionization and loss of combustion enhancing radicals. A qualitative description of the ionization loss was the main goal of this work. The second goal was to develop a microwave SFD to validate Martian atmospheric entry models and explore the prospect of harvesting Martian entry plasma.An atmospheric and kinetic model was developed for Martian atmospheric entry plasma based on the existing Mars data. We found that variations in the entry plasma composition were considerable and must be included in future harvesting schemes.

Download or read book Characterization of Microwave Cavity Discharges in a Supersonic Flow written by Dereth Janette Drake and published by . This book was released on 2009 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Unsteady Supersonic Combustion written by Mingbo Sun and published by Springer Nature. This book was released on 2020-04-14 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes the unsteady phenomena needed to understand supersonic combustion. Following an initial chapter that introduces readers to the basic concepts in and classical studies on unsteady supersonic combustion, the book highlights recent studies on unsteady phenomena, which offer insights on e.g. interactions between acoustic waves and flames, flow dominating instability, ignition instability, flame flashback, and near-blowout-limit combustion. In turn, the book discusses in detail the fundamental mechanisms of these phenomena, and puts forward practical suggestions for future scramjet design.

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 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 Energy Transfer in Non equilibrium Reacting Gas Flows written by Zakari Eckert and published by . This book was released on 2018 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first part of the dissertation focuses on kinetic modeling of non-equilibrium reacting gas flows excited by nanosecond pulse discharges used for experimental studies of plasma assisted combustion kinetics. The present work provides detailed quantitative insight into kinetics of plasma assisted fuel oxidation processes, including generation of excited species by electron impact, dissociation of molecules during collisional quenching of excited species, formation of stable fuel oxidation products, and coupling between vibrational energy relaxation and chemical reaction kinetics in hydrogen-air, hydrogen-oxygen-argon, and hydrocarbon-oxygen-argon mixtures excited by nanosecond pulse discharges. The focus of the second half of the dissertation is on feasibility analysis of a new chemical carbon monoxide laser. Detailed insight is obtained into kinetics of state-specific vibrational energy transfer in non-equilibrium mixtures of CO, N2, and O2, vibrationally excited by an RF discharge and by a chemical reaction between atomic carbon vapor and molecular oxygen, to produce laser gain and laser action in a supersonic flow.

Download or read book Plasma Assisted Combustion written by Wansheng Nie and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a promising technology, plasma-assisted combustion (PAC) has attracted many researchers to explore the effect of PAC on improving the combustion in propulsion devices, such as scramjet, detonation engines, internal engines, and so on. In this chapter, we aim to exhibit the influence of quasi-DC discharge plasma on the operating performance of scramjet combustor and find the internal mechanisms, which may contribute to the development of PAC technology in supersonic combustion. For case one, a plasma filament is generated upstream of fuel jet through quasi-DC discharge in a scramjet combustor; for case two, the plasma is formed across the backward facing step of a flame holding cavity to improve the flame stabilization of the cavity in the scramjet combustor. The two cases are investigated in detail through three-dimensional numerical simulation based on the dominant thermal blocking mechanism. Important parameters including temperature distribution, separation zone, water production, stagnation pressure loss, combustion efficiency, cavity drag, mass exchange rate, and cavity oscillating characteristics are obtained and analyzed. It shows that the quasi-DC discharge plasma does benefit for the improvement of the combustion in a scramjet combustor.

Download or read book External and Internal Plasma Assisted Combustion written by and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Plasma-assisted combustion (PAC) in. subsonic airflow and supersonic airflow was studied in our previous works. Present work is devoted to continuation of plasma assisted combustion study. Four main tasks are considered in this work, namely: * Advanced plasma assisted fuel airfiow mixing, * External and internal plasma assisted combustion in cold airflow and hot airflow, * Electric discharge and plasma parameters in PAC region, * Fuel combustion completeness in airflow.

Download or read book Simulation of Magnetohydrodynamics Turbulence with Application to Plasma assisted Supersonic Combustion written by Kenji Miki and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this thesis is to develop a comprehensive model with the capability of modeling both a high Reynolds number and high magnetic Reynolds number turbulent flow for application to supersonic combustor. The development of this model can be divided into three categories: one, the development of a self-consistent MHD numerical model capable of modeling magnetic turbulence in high magnetic Reynolds number applications. Second, the development of a gas discharge model which models the interaction of externally applied fields in conductive medium. Third, the development of models necessary for studying supersonic combustion applications with plasma-assistance such the extension of chemical kinetics models to extremely high temperature and non-equilibrium phenomenon.

Download or read book Combined Discharge Plasma in Supersonic Airflow written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electric discharge in supersonic airflow and airflow around body with plasma formation were studied in our previous works. Present work is devoted to continuation of the plasma-aerodynamics study. Three main tasks are considered in this work, namely: * Combined discharge (DC discharge + eletron beam) plasma properties in supersonic airflow, * Supersonic airflow around aerodynamic model with combined discharge plasmoid. * Local external combined discharge (CD) plasma assisted combustion near aerodynamic model.

Download or read book Encyclopedia of Plasma Technology Two Volume Set written by J. Leon Shohet and published by CRC Press. This book was released on 2016-12-12 with total page 1654 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technical plasmas have a wide range of industrial applications. The Encyclopedia of Plasma Technology covers all aspects of plasma technology from the fundamentals to a range of applications across a large number of industries and disciplines. Topics covered include nanotechnology, solar cell technology, biomedical and clinical applications, electronic materials, sustainability, and clean technologies. The book bridges materials science, industrial chemistry, physics, and engineering, making it a must have for researchers in industry and academia, as well as those working on application-oriented plasma technologies. Also Available Online This Taylor & Francis encyclopedia is also available through online subscription, offering a variety of extra benefits for researchers, students, and librarians, including: Citation tracking and alerts Active reference linking Saved searches and marked lists HTML and PDF format options Contact Taylor and Francis for more information or to inquire about subscription options and print/online combination packages. US: (Tel) 1.888.318.2367; (E-mail) [email protected] International: (Tel) +44 (0) 20 7017 6062; (E-mail) [email protected]