Understanding Micro-Ramp Control for Shock Boundary Layer Interactions PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Understanding Micro-Ramp Control for Shock Boundary Layer Interactions PDF full book. Access full book title Understanding Micro-Ramp Control for Shock Boundary Layer Interactions by . Download full books in PDF and EPUB format.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 29
Get Book Here
Book Description
Micro-vortex generators (micro-VGs) have the ability to alter the near-wall structure of compressible turbulent boundary layers in such a way that the flow becomes significantly less susceptible to separations and more stable to unsteady disturbances. Due to their extremely small size, micro-VGs are embedded in the boundary layer and may provide reduced viscous drag when compared to traditional vortex generators. Of several candidate micro-VGs, micro-ramps have been found to significantly impact shock boundary layer interaction flows, while being cost-effective, physically robust, and requiring no power sources. Thus detailed study of flow interactions with micro-ramps on a supersonic boundary layer at M=3.0 was investigated using monotone integrated Large Eddy Simulations (MILES) and Reynolds Averaged Navier-Stokes (RANS). A rescale-recycle method was used to efficiently generate turbulent in-flow conditions. Studies showed that the vortical structure generated from the micro-ramp flows through the separation region caused by the impinging shock, which helped to reduce the area of separation.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 29
Get Book Here
Book Description
Micro-vortex generators (micro-VGs) have the ability to alter the near-wall structure of compressible turbulent boundary layers in such a way that the flow becomes significantly less susceptible to separations and more stable to unsteady disturbances. Due to their extremely small size, micro-VGs are embedded in the boundary layer and may provide reduced viscous drag when compared to traditional vortex generators. Of several candidate micro-VGs, micro-ramps have been found to significantly impact shock boundary layer interaction flows, while being cost-effective, physically robust, and requiring no power sources. Thus detailed study of flow interactions with micro-ramps on a supersonic boundary layer at M=3.0 was investigated using monotone integrated Large Eddy Simulations (MILES) and Reynolds Averaged Navier-Stokes (RANS). A rescale-recycle method was used to efficiently generate turbulent in-flow conditions. Studies showed that the vortical structure generated from the micro-ramp flows through the separation region caused by the impinging shock, which helped to reduce the area of separation.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 17
Get Book Here
Book Description
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.
Author: Charles W. Pitt Ford
Publisher:
ISBN:
Category : Boundary layer
Languages : en
Pages : 14
Get Book Here
Book Description
Author: Aaron F. Shinn
Publisher:
ISBN:
Category :
Languages : en
Pages : 172
Get Book Here
Book Description
Author: Holger Babinsky
Publisher: Cambridge University Press
ISBN: 1139498649
Category : Technology & Engineering
Languages : en
Pages : 481
Get Book Here
Book Description
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.
Author: Chaoqun Liu
Publisher: Bentham Science Publishers
ISBN: 1681085976
Category : Technology & Engineering
Languages : en
Pages : 321
Get Book Here
Book Description
This volume presents an implicitly implemented large eddy simulation (ILES) by using the fifth order bandwidth-optimized WENO scheme. The chosen method is applied to make comprehensive studies on ramp flows with and without control at Mach 2.5 and Re=5760. Flow control in the form of microramp vortex generators (MVG) is applied. The results show that a MVG can distinctly reduce the separation zone at the ramp corner and lower the boundary layer shape factor under simulated conditions. A series of new findings about the MVG-ramp flow are obtained, including structures relevant to surface pressure, three-dimensional structures of the re-compression shock waves, a complete surface separation pattern, momentum deficit and a new secondary vortex system. A new mechanism of shock-boundary layer interaction control by MVG associated with a series of vortex rings is also presented. Vortex rings strongly interact with air flow and play an important role in the separation zone reduction. Additionally, readers will learn about the governing equation, boundary condition, high quality grid generation, high order shock capturing scheme and DNS inflow condition in detail. This volume will, therefore, serve as a useful reference for aerospace researchers using LES methods to study shock boundary layer interaction and supersonic flow control.
Author: Konstantinos Kontis
Publisher: Springer Science & Business Media
ISBN: 3642256856
Category : Science
Languages : en
Pages : 1122
Get Book Here
Book Description
The University of Manchester hosted the 28th International Symposium on Shock Waves between 17 and 22 July 2011. The International Symposium on Shock Waves first took place in 1957 in Boston and has since become an internationally acclaimed series of meetings for the wider Shock Wave Community. The ISSW28 focused on the following areas: Blast Waves, Chemically Reacting Flows, Dense Gases and Rarefied Flows, Detonation and Combustion, Diagnostics, Facilities, Flow Visualisation, Hypersonic Flow, Ignition, Impact and Compaction, Multiphase Flow, Nozzle Flow, Numerical Methods, Propulsion, Richtmyer-Meshkov, Shockwave Boundary Layer Interaction, Shock Propagation and Reflection, Shock Vortex Interaction, Shockwave Phenomena and Applications, as well as Medical and Biological Applications. The two Volumes contain the papers presented at the symposium and serve as a reference for the participants of the ISSW 28 and individuals interested in these fields.
Author: David Benjamin Helmer
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 212
Get Book Here
Book Description
A series of measurements were taken of the shock-boundary layer interaction (SBLI) in a Mach 2.1 continuously operated wind tunnel. The SBLI was generated by a small (~1.1mm tall) 20° wedge located on the top wall, and data were taken both in the region near the compression wedge and in the area where this shock impinged on the bottom wall. PIV was the primary measurement tool in both locations, though pressure data were also acquired near the compression wedge. Data were acquired at 4 spanwise locations to study the three-dimensionality of the flow. Both interactions were found to be highly 3-D, with a stronger interaction observed near the channel centerline. Evidence of a corner vortical structure in the compression corner was observed, and substantiated by CFD. Intermittent flow reversal was seen in the reflected shock interaction near the channel centerline, though not in the corners. The data suggest the presence of vortical structures generated near the channel centerline and pushed towards the sidewalls. Following the characterization of the base case, a Monte Carlo experiment was performed in which geometric perturbations were installed along the bottom wall of the wind tunnel and their effect on the flow was studied. The Monte Carlo device was designed and installed at the location predicted to be most sensitive by CFD. The majority of the locations initially tested displayed minimal sensitivity, with only the largest and most upstream quasi-2D cases showing significant effects on the flow at the corner. The perturbation device was redesigned and moved upstream, and additional quasi-2D cases were tested. It was found that some configurations accelerated the flow and strengthened the primary shock, while others slowed the flow and weakened the shock. Overall, the flow was observed to be very sensitive to some perturbations, but only to those located within a limited range of streamwise positions, and with a wide variety of system responses possible.
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781719380089
Category :
Languages : en
Pages : 30
Get Book Here
Book Description
The effectiveness of microramp flow control devices in controlling an oblique shock interaction was tested in the 15- by 15-Centimeter Supersonic Wind Tunnel at NASA Glenn Research Center. Fifteen microramp geometries were tested varying the height, chord length, and spacing between ramps. Measurements of the boundary layer properties downstream of the shock reflection were analyzed using design of experiments methods. Results from main effects, D-optimal, full factorial, and central composite designs were compared. The designs provided consistent results for a single variable optimization. Hirt, Stefanie M. and Anderson, Bernhard H. Glenn Research Center OBLIQUE SHOCK WAVES; BOUNDARY LAYERS; SHOCK WAVE INTERACTION; EXPERIMENT DESIGN; FACTORIAL DESIGN; SUPERSONIC WIND TUNNELS; SPACING
Author: L. Venkatakrishnan
Publisher: Springer Nature
ISBN: 9811551839
Category : Technology & Engineering
Languages : en
Pages : 555
Get Book Here
Book Description
This book includes select papers presented during the 16th Asian Congress of Fluid Mechanics, held in JNCASR, Bangalore, and presents the latest developments in computational, experimental and theoretical research as well as industrial and technological advances. This book is of interest to researchers working in the field of fluid mechanics.
