High Order LES for Supersonic Ramp Flow Control with MVG

High Order LES for Supersonic Ramp Flow Control with MVG PDF Author: Yonghua Yan
Publisher:
ISBN:
Category : Shock waves
Languages : en
Pages :

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Book Description
An implicitly implemented large eddy simulation by using the fifth order bandwidth-optimized WENO scheme 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 MVG can distinctly reduce the separation zone at the ramp corner and lower the boundary layer shape factor under the condition of the computation. A series of new findings are obtained about the MVG-ramp flow including the threedimensional vortex structure generated by MVG. The mechanism about the formation vortex ring structure and its interaction with shock wave at the ramp corner is deeply studied. Vortex rings strongly interact with the flow and play an important role in the separation zone reduction. It shows that the ring structure does not break down and keeps it topology after penetrating the strong shock wave and the oblique shocks is influenced a lot by the induced flow field from rings. The bump of the 3D shock wave surface is discovered and its mechanism is explained.

High Order LES for Supersonic Ramp Flow Control with MVG

High Order LES for Supersonic Ramp Flow Control with MVG PDF Author: Yonghua Yan
Publisher:
ISBN:
Category : Shock waves
Languages : en
Pages :

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Book Description
An implicitly implemented large eddy simulation by using the fifth order bandwidth-optimized WENO scheme 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 MVG can distinctly reduce the separation zone at the ramp corner and lower the boundary layer shape factor under the condition of the computation. A series of new findings are obtained about the MVG-ramp flow including the threedimensional vortex structure generated by MVG. The mechanism about the formation vortex ring structure and its interaction with shock wave at the ramp corner is deeply studied. Vortex rings strongly interact with the flow and play an important role in the separation zone reduction. It shows that the ring structure does not break down and keeps it topology after penetrating the strong shock wave and the oblique shocks is influenced a lot by the induced flow field from rings. The bump of the 3D shock wave surface is discovered and its mechanism is explained.

High Order Large Eddy Simulation for Shock-Boundary Layer Interaction Control by a Micro-ramp Vortex Generator

High Order Large Eddy Simulation for Shock-Boundary Layer Interaction Control by a Micro-ramp Vortex Generator PDF Author: Chaoqun Liu
Publisher: Bentham Science Publishers
ISBN: 1681085976
Category : Technology & Engineering
Languages : en
Pages : 321

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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.

Liutex and Its Applications in Turbulence Research

Liutex and Its Applications in Turbulence Research PDF Author: Chaoqun Liu
Publisher: Academic Press
ISBN: 0128190248
Category : Science
Languages : en
Pages : 458

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Book Description
Liutex and Its Applications in Turbulence Research reviews the history of vortex definition, provides an accurate mathematical definition of vortices, and explains their applications in flow transition, turbulent flow, flow control, and turbulent flow experiments. The book explains the term "Rortex" as a mathematically defined rigid rotation of fluids or vortex, which could help solve many longstanding problems in turbulence research. The accurate mathematical definition of the vortex is important in a range of industrial contexts, including aerospace, turbine machinery, combustion, and electronic cooling systems, so there are many areas of research that can benefit from the innovations described here. This book provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence. Important theory and methodologies used for developing these laws are described in detail, including: the classification of the conventional turbulent boundary layer concept based on proper velocity scaling; the methodology for identification of the scales of velocity, temperature, and length needed to establish the law; and the discovery, proof, and strict validations of the laws, with both Reynolds and Prandtl number independency properties using DNS data. The establishment of these statistical laws is important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence. Provides an accurate mathematical definition of vortices Provides a thorough survey of the latest research in generalized and flow-thermal, unified, law-of-the-wall for wall-bounded turbulence Explains the term “Rortex as a mathematically defined rigid rotation of fluids or vortex Covers the statistical laws important to modern fluid mechanics and heat transfer research, and greatly expands our understanding of wall-bounded turbulence

Direct Numerical Simulation of Supersonic Turbulent Ramp and Step Flow

Direct Numerical Simulation of Supersonic Turbulent Ramp and Step Flow PDF Author: I. Klutchnikov
Publisher:
ISBN:
Category :
Languages : en
Pages : 8

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Book Description
Direct numerical simulations of compressible fluid flow are performed for subsonic and supersonic channel flow with two symmetrically backward facing steps and for a supersonic compression ramp flow field. Spatial derivatives are represented by a central scheme of high order difference operators (N=2,4,6,8 ...) that is used together with artificial dissipation of order N.A two-step Richtmyer scheme is employed for time integration. In regions with steep gradients flux-corrected transport (FCT) according to Boris and Book is applied. Preliminary results are presented for Mach number 1.5 in case of the channel flow and further results for Mach number 2.84 in case of the ramp with a ramp angle of 24 degrees.

The Proceedings of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2021), Volume 1

The Proceedings of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2021), Volume 1 PDF Author: Sangchul Lee
Publisher: Springer Nature
ISBN: 9811926891
Category : Technology & Engineering
Languages : en
Pages : 1027

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Book Description
This proceeding comprises peer-reviewed papers of the 2021 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2021), held from 15-17 November 2021 in Jeju, South Korea. This book deals with various themes on computational fluid dynamics, wind tunnel testing, flow visualization, UAV design, flight simulation, satellite attitude control, aeroelasticity and control, combustion analysis, fuel injection, cooling systems, spacecraft propulsion and so forth. So, this book can be very helpful not only for the researchers of universities and academic institutes, but also for the industry engineers who are interested in the current and future advanced topics in aerospace technology.

Passive and Active Control of Supersonic Axisymmetric Base Flows: Direct Numerical Simulations and Large-Eddy Simulations

Passive and Active Control of Supersonic Axisymmetric Base Flows: Direct Numerical Simulations and Large-Eddy Simulations PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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Book Description
A new compressible Navier-Stokes code in cylindrical coordinates was developed for investigating axisymmetric wakes of bluff-based bodies in supersonic flows. In this code, high-order compact finite differences derived for non-equidistant grids are employed and a new stare-of-the-art axis treatment is incorporated. Additionally, the fully three-dimensional transport equations for turbulent kinetic energy and turbulent dissipation are implemented to enable (steady or unsteady) Reynolds Averaged Navier Stokes (RANS) simulations. Furthermore, a new "Flow Simulation Methodology" (FSM) was developed for computing complex compressible flows. The centerpiece of FSM) is a strategy to provide the proper amount of modeling of the subgrid scales. This is accomplished by a "contribution function" which locally and instantaneously compares the smallest relevant scales to the local grid size. The contribution function is designed such that it provides no modeling if the computation is locally well resolved so that the computation approaches a Direct Numerical Simulation (DNS) in the fine grid limit, or provides modeling of all scales in the coarse grid limit and thus approaches an unsteady PANS (URANS) calculation. In between these resolution limits, the contribution function adjusts the necessary modeling for the unresolved scales while the larger (resolved) scales are computed as in traditional Large Eddy Simulations (LES) . Preliminary results have shown that the new high- order code has great advantages for supersonic base flow simulations and that calculations, in particular together with FSM), will allow simulations of supersonic base flows at much higher Reynolds numbers than possible with conventional LES.

28th International Symposium on Shock Waves

28th International Symposium on Shock Waves PDF Author: Konstantinos Kontis
Publisher: Springer Science & Business Media
ISBN: 3642256856
Category : Science
Languages : en
Pages : 1122

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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.

Autonomous Vehicles

Autonomous Vehicles PDF Author: George Dekoulis
Publisher: BoD – Books on Demand
ISBN: 1839629215
Category : Transportation
Languages : en
Pages : 212

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Book Description
This edited volume, Autonomous Vehicles, is a collection of reviewed and relevant research chapters, offering a comprehensive overview of recent developments in the field of vehicle autonomy. The book comprises nine chapters authored by various researchers and edited by an expert active in the field of study. All chapters are complete in itself but united under a common research study topic. This publication aims to provide a thorough overview of the latest research efforts by international authors, open new possible research paths for further novel developments, and to inspire the younger generations into pursuing relevant academic studies and professional careers within the autonomous vehicle field.

Large-eddy Simulation of Supersonic Cavity Flowfields Including Flow Control

Large-eddy Simulation of Supersonic Cavity Flowfields Including Flow Control PDF Author: D. P. Rizzetta
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Steady and Unsteady Supersonic Flow Control with Energy Addition

Steady and Unsteady Supersonic Flow Control with Energy Addition PDF Author: M. N. Shneider
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description