Download or read book Control of the Oblique Shockwave boundary Layer Interaction in a Supersonic Inlet written by James Bellinger and published by . This book was released on 2008 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In a supersonic engine inlet, the adverse pressure gradient caused by an oblique shockwave generated by an inlet cone interacts with low momentum boundary layer air at the inlet wall to create a region of recirculating flow called a separation bubble. This separated region reduces the effective area of the engine inlet, requiring a larger inlet to get the desired mass flow rate. As a result the engine must be larger and heavier. Over the past year, investigations have been done into the viability of controlling this oblique shockwave/boundary layer interaction with plasma actuators, using a supersonic wind tunnel simulating an engine inlet. Plasma actuators were considered for this application due to their ability to generate streamwise vortices in the flow. Vortices move low momentum boundary layer air out into the free stream and high momentum free stream air down into the boundary layer, thus increasing the momentum in the interaction region and reducing or eliminating separation. A test section containing a 10° shock generator and adjustable floor was designed and installed into an existing supersonic wind tunnel. Plasma actuators were tested at various frequencies and distances to the oblique shock impingement point, and their effect was visualized using schlieren photography.

Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.

Download or read book Evaluation of Some Control volume Techniques for Analysis of Shock boundary layer Interactions in Supersonic Inlets written by Warren R. Hingst and published by . This book was released on 1975 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Understanding Micro Ramp Control of Supersonic Shock Wave Boundary Layer Interactions written by and published by . This book was released on 2007 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research investigated the potential of micro-ramp sub-boundary layer vortex generators for flow control of oblique shock boundary layer interactions (SBLIs) which is relevant to supersonic engine inlets. These novel devices can delay shock-induced separation and improve boundary layer health, thus offering the potential to reduce the bleed requirement in intakes. Micro-ramp Experiments have been conducted at Mach 2.5, to determine the nature of flow controlled by micro-ramps and investigate their ability to delay separation in a reflected shock interaction. Various ramp sizes between 30% and 90% of boundary layer thickness were investigated. The details of the vortical flow generated by such devices was identified. The general flow features were found to scale with device height and it is suggested that smaller devices need to be placed closer to the expected adverse pressure gradients. When applied to a separated oblique shock SBLI micro-ramps were not observed to eliminate flow separation, although they were shown to break up separated regions. Other performance indicators across the SBLI were also improved through the application of the devices.

Download or read book Control of Supersonic Mixed compression Inlets Using Localized Arc Filament Plasma Actuators written by Nathan Joseph Webb and published by . This book was released on 2010 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Shock wave/boundary layer interactions (SWBLIs) occur in many supersonic internal flow applications, specifically in mixed compression inlets, as well as in external flows. In this study a nominally Mach 2 mixed compression inlet is modeled by two experimental setups: 1) A compression ramp-generated impinging SWBLI, and 2) a variable angle wedge (VAW) generated impinging SWBLI. The compression ramp and the wedge both serve to generate an oblique shock wave that impinges on the boundary layer on the opposite surface of the wind tunnel. This produces an impinging SWBLI within the test section that replicates the flow found in a mixed compression inlet. A SWBLI can cause flow separation and it is desirable to efficiently prevent this to avoid the many adverse consequences that may result otherwise. The goal of this study is to investigate the ability of localized arc-filament plasma actuators (LAFPAs) to effectively control the interaction. The LAFPAs show significant ability to beneficially affect the SWBLI depending on various operating parameters such as geometry and forcing Strouhal number. This ability apparently stems from a manipulation of instabilities naturally present in the flow. For the compression ramp facility the LAFPAs were most effective when located upstream of the shock foot, forcing with a Strouhal number of 0.03, and operated in-phase. The VAW facility is currently being debugged and will be used for future detailed experiments investigating the control authority of the LAFPAs.

Download or read book Pressure Recovery at Supersonic Speeds Through Annular Duct Inlets Situated in a Region of Appreciable Boundary Layer written by George B. Brajnikoff and published by . This book was released on 1948 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains the results of an experimental investigation made at Mach numbers between 1.36 and 2.01 of the total-pressure recovery attainable with a model having a ramp ahead of an annular inlet for the purpose of reducing the entrance Mach number by means of an oblique shock wave. It was found that the recovery improved considerably with increasing ramp angle and that a model with a 15 degree ramp produced approximately four-fifths of the recovery through a normal shock wave occurring at the free-stream Mach number. Use of ramp angles greater than 15 degrees resulted in unsteady flow through the induction system and a reduction in recovery.

Download or read book Wind Tunnels and Experimental Fluid Dynamics Research written by Jorge Colman Lerner and published by BoD – Books on Demand. This book was released on 2011-07-27 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book "Wind Tunnels and Experimental Fluid Dynamics Research" is comprised of 33 chapters divided in five sections. The first 12 chapters discuss wind tunnel facilities and experiments in incompressible flow, while the next seven chapters deal with building dynamics, flow control and fluid mechanics. Third section of the book is dedicated to chapters discussing aerodynamic field measurements and real full scale analysis (chapters 20-22). Chapters in the last two sections deal with turbulent structure analysis (chapters 23-25) and wind tunnels in compressible flow (chapters 26-33). Contributions from a large number of international experts make this publication a highly valuable resource in wind tunnels and fluid dynamics field of research.

Download or read book Control of Shock Wave Boundary Layer Interactions by Bleed in Supersonic Mixed Compression Inlets written by Michael K. Fukuda and published by . This book was released on 1975 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shock Wave Interactions written by Konstantinos Kontis and published by Springer. This book was released on 2018-03-28 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This edited monograph contains the proceedings of the International Shock Interaction Symposium, which emerged as an heir to both the Mach Reflection and Shock Vortex Interaction Symposia. These scientific biannual meetings provide an ideal platform to expose new developments and discuss recent challenges in the field of shock wave interaction phenomena. The goal of the symposia is to offer a forum for international interaction between young and established scientists in the field of shock and blast wave interaction phenomena. The target audience of this book comprises primarily researchers and experts in the field of shock waves, but the book may also be beneficial for young scientists and graduate students alike.

Download or read book 31st International Symposium on Shock Waves 1 written by Akihiro Sasoh and published by Springer. This book was released on 2019-03-21 with total page 1188 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the first volume of a two volume set which presents the results of the 31st International Symposium on Shock Waves (ISSW31), held in Nagoya, Japan in 2017. It was organized with support from the International Shock Wave Institute (ISWI), Shock Wave Research Society of Japan, School of Engineering of Nagoya University, and other societies, organizations, governments and industry. The ISSW31 focused on the following areas: Blast waves, chemical reacting flows, chemical kinetics, detonation and combustion, ignition, facilities, diagnostics, flow visualization, spectroscopy, numerical methods, shock waves in rarefied flows, shock waves in dense gases, shock waves in liquids, shock waves in solids, impact and compaction, supersonic jet, multiphase flow, plasmas, magnetohyrdrodynamics, propulsion, shock waves in internal flows, pseudo-shock wave and shock train, nozzle flow, re-entry gasdynamics, shock waves in space, Richtmyer-Meshkov instability, shock/boundary layer interaction, shock/vortex interaction, shock wave reflection/interaction, shock wave interaction with dusty media, shock wave interaction with granular media, shock wave interaction with porous media, shock wave interaction with obstacles, supersonic and hypersonic flows, sonic boom, shock wave focusing, safety against shock loading, shock waves for material processing, shock-like phenomena, and shock wave education. These proceedings contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 31 and individuals interested in these fields.

Download or read book Smart Mesoflaps for Aeroelastic Transpiration to Control Shock Boundary Layer Interactions written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The grant investigated a new concept in shock-wave/boundary-layer interaction control: tile use of aeroelastic mesoflaps to provide efficient recirculation transpiration. Appendix 1A presents a set of Power-Point slides which summarize the major finding of the study and also suggest a potential path forward to develop the technology and transition it to allow a bleedless supersonic inlet. As such, the goal would be to allow the overall benefits of a zero-bleed boundary layer control system into supersonic aircraft inlets: via retrofitting current inlets (e.g. the F-18E/F) or incorporating into design of future aircraft (e.g. the Long Range Strike Aircraft). As noted on Slide 2, the advantages of a bleedless inlet as evaluated by the aircraft industry are substantial and can considered in terms of either extended range (as much as 20%) or reduced gross take-off weight (as much as 10% as detailed in Part 7). As discussed on slides 2-9, tile aerodynamic benefits for tile mesoflaps over conventional recirculation transpiration with a porous plate include improved aerodynamics for subsonic conditions, more aerodynamic aerodynamic bleed and injection for shock interactions and increased shock stability. These benefits have been quantified for oblique impinging shocks, ramp-generated oblique shocks and normal shocks (Part 2). Additional research was conducted to understand tile structural dynamic issues (Parts 3 and 4) and how a closed-loop control system might be employed in order to allow further performance increases (Part 5). Appendix 1B gives an overview of the how these various research activities were integrated together.

Download or read book 30th International Symposium on Shock Waves 2 written by Gabi Ben-Dor and published by Springer. This book was released on 2017-08-01 with total page 681 pages. Available in PDF, EPUB and Kindle. Book excerpt: These proceedings collect the papers presented at the 30th International Symposium on Shock Waves (ISSW30), which was held in Tel-Aviv Israel from July 19 to July 24, 2015. The Symposium was organized by Ortra Ltd. The ISSW30 focused on the state of knowledge of the following areas: Nozzle Flow, Supersonic and Hypersonic Flows with Shocks, Supersonic Jets, Chemical Kinetics, Chemical Reacting Flows, Detonation, Combustion, Ignition, Shock Wave Reflection and Interaction, Shock Wave Interaction with Obstacles, Shock Wave Interaction with Porous Media, Shock Wave Interaction with Granular Media, Shock Wave Interaction with Dusty Media, Plasma, Magnetohyrdrodynamics, Re-entry to Earth Atmosphere, Shock Waves in Rarefied Gases, Shock Waves in Condensed Matter (Solids and Liquids), Shock Waves in Dense Gases, Shock Wave Focusing, Richtmyer-Meshkov Instability, Shock Boundary Layer Interaction, Multiphase Flow, Blast Waves, Facilities, Flow Visualization, and Numerical Methods. The two volumes serve as a reference for the participants of the ISSW30 and anyone interested in these fields.

Download or read book Large Eddy Simulation of Supersonic Inlet Flows written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of a shock wave with a turbulent boundary layer is a central problem in supersonic inlet flows. This work uses numerical and analytical techniques to study shock/turbulence interaction in order to identify and explain factors important in shock/boundary layer interaction. Direct numerical simulation of a normal shock wave with an isotropic turbulent field of vorticity and entropy fluctuations showed that negative upstream correlation between the vorticity and entropy fluctuations enhances the turbulence across the shock. Positive upstream correlation has a suppressing effect. A new numerical method providing excellent high wavenumber resolution while reducing the computational cost was developed. A model with no adjustable constants was developed to study the vortex breakdown resulting from the interaction of canard or forbody vortices with the shock waves in a supersonic inlet flow. Very good agreement with both experiment and computation was obtained. A numerical method to compute shock/turbulence interaction using a conservative form of the Large Eddy Simulation (LES) equations has been developed and validated. LES of the interaction of isotropic turbulence with a normal shock was performed and comparisons with direct numerical simulation (DNS) results were favorable. A new Fortran 90 code has been developed for the computation of shock/turbulence interaction. The code is an improved version of codes used previously in shock/turbulence interaction simulations.

Download or read book Turbulent Shear Layers in Supersonic Flow written by Alexander J. Smits and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: A good understanding of turbulent compressible flows is essential to the design and operation of high-speed vehicles. Such flows occur, for example, in the external flow over the surfaces of supersonic aircraft, and in the internal flow through the engines. Our ability to predict the aerodynamic lift, drag, propulsion and maneuverability of high-speed vehicles is crucially dependent on our knowledge of turbulent shear layers, and our understanding of their behavior in the presence of shock waves and regions of changing pressure. Turbulent Shear Layers in Supersonic Flow provides a comprehensive introduction to the field, and helps provide a basis for future work in this area. Wherever possible we use the available experimental work, and the results from numerical simulations to illustrate and develop a physical understanding of turbulent compressible flows.

Download or read book Interactions Entre Ondes de Choc Et Couches Limites Dans Les Ecoulements Supersoniques Et Hypersoniques written by and published by . This book was released on 1993 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Shock-wave/boundary-layer interactions continue to be ubiquitous phenomena in supersonic and hypersonic aerodynamics, and their importance is often critical as, for example, for hypersonic controls and for air intakes in general. This is the reason for the continuous research efforts in this field, aiming at developing reliable methodologies for future vehicle design. Results from these programmes have been reported. The present course reviews the recent progress in this field. In particular, a large part of the course is devoted to swept interactions, both laminar and turbulent, including a discussion of the following topics: (1) The flowfield structure; (2) The scaling and similarity laws; (3) The effect of shock strength on flow features; (4) The effect of shock generator geometry for a given shock strength; (5) Experimental techniques, in particular optical techniques, for the investigation of swept interactions; and (6) Contributions of numerical simulations to the understanding of swept interactions. A limiting factor in the understanding and ability to predict shock wave/boundary-layer interactions is a good knowledge of turbulence behavior. A lecture is devoted specifically to hypersonic interactions."--DTIC.

Download or read book Flow Control written by Thomas C. Corke and published by Cambridge University Press. This book was released on 2024-04-11 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive treatment of passive and active flow control in fluid dynamics, with an emphasis on utilizing fluid instabilities for enhancing control performance. Examples are given from a wide range of technologically important flow fields occurring in aerospace applications, from low-subsonic to hypersonic Mach numbers. This essential book can be used for both research and teaching on the topics of fluid instabilities, fluid measurement and flow actuator techniques, and problem sets are provided at the end of each chapter to reinforce key concepts and further extend readers' understanding of the field. The solutions manual is available as a online resource for instructors. The text is well suited for both graduate students in fluid dynamics and for practising engineers in the aerodynamics design field.

Download or read book Turbulence Modeling Validation Testing and Development written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this work is to provide accurate numerical solutions for selected flow fields and to compare and evaluate the performance of selected turbulence models with experimental results. Four popular turbulence models have been tested and validated against experimental data often turbulent flows. The models are: (1) the two-equation k-epsilon model of Wilcox, (2) the two-equation k-epsilon model of Launder and Sharma, (3) the two-equation k-omega/k-epsilon SST model of Menter, and (4) the one-equation model of Spalart and Allmaras. The flows investigated are five free shear flows consisting of a mixing layer, a round jet, a plane jet, a plane wake, and a compressible mixing layer; and five boundary layer flows consisting of an incompressible flat plate, a Mach 5 adiabatic flat plate, a separated boundary layer, an axisymmetric shock-wave/boundary layer interaction, and an RAE 2822 transonic airfoil. The experimental data for these flows are well established and have been extensively used in model developments. The results are shown in the following four sections: Part A describes the equations of motion and boundary conditions; Part B describes the model equations, constants, parameters, boundary conditions, and numerical implementation; and Parts C and D describe the experimental data and the performance of the models in the free-shear flows and the boundary layer flows, respectively. Bardina, J. E. and Huang, P. G. and Coakley, T. J. Ames Research Center...