Download or read book Localized Flow Control in High Speed Flows Using Laser Energy Deposition written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The capability for localized flow control in high speed flows using laser energy deposition has been investigated in a collaborative computational and experimental program. Three proposed applications have been comprehensively studied. First, two models of laser energy deposition in air have been developed and validated by comparison with experiment. The first model is an engineering approach wherein the laser energy deposition is treated as an energy release in a perfect gas. The second model is a detailed physical approach which incorporates real gas chemistry with an eleven species model of air. Comparison with experimental measurements of static temperature, density and velocity (one-component) show good agreement with both models outside the plasma region. Second, a detailed 3-D simulation of laser energy deposition upstream of intersecting shocks at Mach 3.45 demonstrated the capability to force transition from Mach Reflection (MR) to Regular Reflection (RR) in the Dual Solution Domain. This result is particularly important for control of MR to RR transition in high speed inlets for scramjet-powered air vehicles. A companion experimental study showed a momentary reduction in the Mach stem height by 70%, but a Mach Reflection was recovered apparently due to freestream turbulence. Third, detailed 3-D simulations of laser energy deposition upstream of an isolated sphere and an Edney IV interaction at Mach 3.45 were performed. Results show the fundamental features observed in the accompanying experiments.
Download or read book Localized Flow Control with Energy Deposition written by Russell G. Adelgren and published by . This book was released on 2002 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of experiments with energy deposition via laser-induced optical breakdown of air, i.e., a laser spark, have been performed. These experiments have demonstrated the possibility of using a laser spark for supersonic flow control. A focused Nd:YAG laser (pulse time of 10 nanoseconds, pulse frequency of 10 Hz, and capable of energy levels up to 600 milli-Joules per pulse) was used to create the energy deposition laser spark. This laser energy deposition was then tested in quiescent air, upstream of a Mach 3.45 sphere with and without shock impingement, into shock structures within the dual solution domain, and into a compressible shear layer.
Download or read book Localized Flow Control by Laser Energy Deposition Applied to Edney IV Shock Impingement and Intersecting Shocks written by R. Adelgren 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 Localized Flow Control with Energy Deposition written by Russell G. Adelgren and published by . This book was released on 2002 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Deposition for High Speed Flow Control written by Doyle D. Knight and published by Cambridge University Press. This book was released on 2019-02-21 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by a leading expert in the field, this book presents a novel method for controlling high-speed flows past aerodynamic shapes using energy deposition via direct current (DC), laser or microwave discharge, and describes selected applications in supersonic and hypersonic flows. Emphasizing a deductive approach, the fundamental physical principles provided give an understanding of the simplified mathematical models derived therefrom. These features, along with an extensive set of 55 simulations, make the book an invaluable reference that will be of interest to researchers and graduate students working in aerospace engineering and in plasma physics.
Download or read book Numerical Simulations of Laser Energy Deposition for Supersonic Flow Control written by Ramnath Kandala and published by . This book was released on 2005 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Directed Energy Deposition Flow Control for High Speed Intake Applications written by Andrew Russell and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aerodynamic Heating in Supersonic and Hypersonic Flows written by Mostafa Barzegar Gerdroodbary and published by Elsevier. This book was released on 2022-10-11 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamic Heating in Supersonic and Hypersonic Flows: Advanced Techniques for Drag and Aero-heating Reduction explores the pros and cons of different heat reduction techniques on other characteristics of hypersonic vehicles. The book begins with an introduction of flow feature around the forebody of space vehicles and explains the main parameters on drag force and heat production in this region. The text then discusses the impact of severe heat production on the nose of hypervelocity vehicles, different reduction techniques for aerodynamic heating, and current practical applications for forebody shock control devices. Delivers valuable insight for aerospace engineers, postgraduate students, and researchers. Presents computational results of different cooling systems for drag and heat reduction around nose cones Explains mechanisms of drag reduction via mechanical, fluidic, and thermal systems Provides comprehensive details about the aerodynamics of space vehicles and the different shock features in the forebody of super/hypersonic vehicles Describes how numerical simulations are used for the development of the current design of forebody of super/hypersonic vehicles
Download or read book Aeronautics and Astronautics written by Max Mulder and published by BoD – Books on Demand. This book was released on 2011-09-12 with total page 626 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 Compressibility Turbulence and High Speed Flow written by Thomas B. Gatski and published by Academic Press. This book was released on 2013-03-05 with total page 343 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and an extensive discussion of the various approaches used in predicting both free shear and wall bounded flows is presented. Experimental measurement techniques common to the compressible flow regime are introduced with particular emphasis on the unique challenges presented by high speed flows. Both experimental and numerical simulation work is supplied throughout to provide the reader with an overall perspective of current trends. An introduction to current techniques in compressible turbulent flow analysis An approach that enables engineers to identify and solve complex compressible flow challenges Prediction methodologies, including the Reynolds-averaged Navier Stokes (RANS) method, scale filtered methods and direct numerical simulation (DNS) Current strategies focusing on compressible flow control
Download or read book Pulsed Discharge Plasmas written by Tao Shao and published by Springer Nature. This book was released on 2023-07-14 with total page 1028 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights the latest progress in pulsed discharge plasmas presented by front-line researchers worldwide. The science and technology surrounding pulsed discharge plasmas is advanced through a wide scope of interdisciplinary studies into pulsed power and plasma physics. Pulsed discharge plasmas with high-power density, high E/N and high-energy electrons can effectively generate highly reactive plasma. Related applications have gathered strong interests in various fields. With contributions from global scientists, the book elaborates on the theories, numerical simulations, diagnostic methods, discharge characteristics and application technologies of pulsed discharge plasmas. The book is divided into three parts with a total of 35 chapters, including 11 chapters on pulsed discharge generation and mechanism, 12 chapters on pulsed discharge characterization and 12 chapters on pulsed discharge applications (wastewater treatments, biomedicine, surface modification, and energy conversion, etc). The book is a must-have reference for researchers and engineers in related fields and graduate students interested in the subject.
Download or read book Fundamental Physics and Application of Plasma Actuators for High speed Flows written by Eli S. Lazar and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this dissertation, a detailed investigation is given discussing three plasma-based flow control methods. These methods included plasma generated by laser energy, microwaves, and electric arc. The plasma generated by laser energy was also applied to a sonic transverse jet in a supersonic cross flow. Lastly, the particle image velocimetry diagnostic was considered and a technique developed to evaluate measurement uncertainty and using experimental velocity data to solve for density from the continuity equation. In the laser-spark system, the effect of ambient pressure in the range of 0.1 to 1.0 atm and wavelength (266 nm and 532 nm) on the size, temperature, electron number density, and fraction of laser energy absorbed in a laser-induced plasma in air has been conducted. The plasma was generated by using optics to focus the laser energy. The focused laser pulse resulted in the induced optical breakdown of air, creating a plasma to perturb the flow field. As pressure or wavelength are reduced, the size of the plasma, its electron number density, and the fraction of incident laser energy that is absorbed are all found to decrease significantly. For the plasma generated by microwaves, the feasibility of using the system for flow control was demonstrated at pressures ranging from 0.05 atm to 1 atm and for pulsing frequencies between 400 Hz to 10 kHz. The setup was based on a quarter-wave coaxial resonator being operated with a microwave frequency of 2.45 GHz. Analysis of reflected power measurements suggested that the microwave energy could be best coupled into the resonator by using a small inductive loop, where the geometry can be experimentally optimized. The plasma was first characterized by recording images of the emission and taking temporal emission waveform profiles. Tests were conducted in quiescent air and analyzed with schlieren photography to determine the effectiveness of a plasma pulse to produce an instantaneous flow perturbation. Examination of phase averaged schlieren images revealed that a blast was produced by the emission and could be used to alter a flow field. The emission was also thermally characterized through emission spectroscopy measurements where the vibrational and rotational temperatures of the plasma were determined. The last system considered was a localized arc filament plasma actuator, or LAFPA-type device. The system creates electric arcs by generating electric fields in the range of 20 kV/cm between two pin-type electrodes. The potential of the actuator to influence surrounding quiescent flow was investigated using emission imaging, schlieren imaging, current and voltage probes, particle image velocimetry (PIV), and emission spectroscopy. The schlieren imaging revealed a potential to cause blast 0́−Mach0́+ waves and a synthetic jet with controllable directionality dependent on cavity orientation. The electric measurements revealed that, in order to increase the power discharged by the plasma, the electrode separation will only aid mildly and that an optimum plasma current exists (between 300-400 mA for the tested parameter space). The PIV data were acquired for various actuation frequencies and showed a trend between discharge frequency and maximum induced jet velocity. Finally, the emission spectroscopy data were acquired for four different cases: two electrode separations and two plasma currents. For each of the four conditions tested, the spectrum fit very well to a thermal distribution for early times in the emission. However, at later times in the emission, the spectrum no longer matched that of the second positive system under optically thick conditions for any combination of rotational and vibrational temperatures. Using the plasma generated by laser energy, an experimental investigation of flow control on a sonic underexpanded jet injected normally into a Mach 2.45 crossflow is reported. The jet exit geometry was circular and was operated at a jet-to-crossflow momentum flux ratio of 1.7. The unperturbed flow field was analyzed with schlieren imaging, PIV velocity data, surface oil flow visualizations, and pressure sensitive paint measurements. As a means of excitation to the flow field, the plasma energy was focused in the center of the jet exit at three different vertical locations. The perturbed resulting flow field was analyzed with schlieren photography and particle image velocimetry. Analysis of phase averaged schlieren images suggested that the resulting blast wave from the laser pulse disrupted the structure of the barrel shock and Mach disk. The two-component velocity field data revealed that the excitation pulse also caused a perturbation to the jet shear layer and induced the formation of vortices that convect downstream. Finally, additional techniques were developed for the PIV diagnostics. First, while PIV is an established experimental technique for determining a velocity field, quantifying the uncertainty related with this method remains a challenging task. To this end, four sources of uncertainty are assessed: equipment, particle lag, sampling size, and processing algorithm. An example uncertainty analysis is conducted for a transverse sonic jet injected into a supersonic crossflow. However, the analysis is not specific to the example flow field and may be generally applied to any mean velocity field. Secondly, using the velocity data from PIV, a technique was developed to solve for density from the continuity equation over the entire flow field. The technique is validated using data from CFD simulations and demonstrated for experimental data for two flow fields.
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2007 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plasma Dynamics for Aerospace Engineering written by Joseph J. S. Shang and published by Cambridge University Press. This book was released on 2018-06-21 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This valuable resource summarizes the past fifty years' basic research accomplishments in plasma dynamics for aerospace engineering, presenting these results in a comprehensive volume that will be an asset to any professional in the field. It offers a comprehensive review of the foundation of plasma dynamics while integrating the most recently developed modeling and simulation techniques with the theoretic physics, including the state-of-the-art numerical algorithms. Several first-ever demonstrations for innovations and incisive explanations for previously unexplained observations are included. All the necessary formulations for technical evaluation to engineering applications are derived from the first principle by statistic and quantum mechanics, and led to physics-based computational simulations for practical applications. The computer-aided procedures directly engage the reader to duplicate findings that are nearly impossible by using ground-based experimental facilities. Plasma Dynamics for Aerospace Engineering will allow readers to reach an incisive understanding of plasma physics.
Download or read book Flow Control Using Energy Deposition at Mach 5 written by Leichao Yang and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Understanding Flow Physics and Control in an Aggressively Offset High speed Inlet diffuser Model written by Collin James O'Neill and published by . This book was released on 2020 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: A class of plasma actuators called localized arc-filament actuators (LAFPAs) have been shown to be successful in controlling flows similar to that through an offset diffuser. The control authority of LAFPAs was explored within a scale offset diffuser model. The performance of the diffuser without control was thoroughly evaluated at Mach numbers ranging from 0.5 to 0.8 to provide a baseline with which to compare the efficacy of LAFPAs. Baseline oil-flow visualization, centerline static pressure measurements, and AIP total pressure measurements found results consistent with literature. The secondary flows within the diffuser were found to be the dominant mechanism over separation in producing distortion. The LAFPA control strategy relied upon an instability in the separation region, which did not appear to exist due to the modification of the separation shear layer by the crossflow. Therefore, the dominance of the secondary flows rendered LAFPAs ineffective in controlling this flow.
Download or read book 41st AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2003 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
