Download or read book Large Eddy Simulation of Synthetic Jets in the Context of Flow Control written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time Accurate Simulations of Synthetic Jet Based Flow Control for An Axisymmetric Spinning Body written by and published by . This book was released on 2004 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a computational study undertaken to consider the aerodynamic effect of synthetic jets as a means of providing the control authority needed to maneuver a projectile at a low subsonic speed. A time-accurate Navier-Stokes computational technique has been used to obtain numerical solutions for the unsteady jet-interaction flow field for a spinning projectile at a subsonic speed, Mach 0.24, and angle of attack, 0 degree. Numerical solutions have been obtained by Reynolds-averaged Navier-Stokes (RANS) and hybrid RANS-large-eddy simulation turbulence models. Unsteady numerical results show the effect of the jet on the flow field and the aerodynamic coefficients, particularly the lift force. These numerical results are being used to assess if synthetic jets can be used to provide the control authority needed for maneuvering munitions to hit the targets with precision.
Download or read book Synthetic Jets written by Kamran Mohseni and published by CRC Press. This book was released on 2014-09-17 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compiles Information from a Multitude of SourcesSynthetic jets have been used in numerous applications, and are part of an emergent field. Accumulating information from hundreds of journal articles and conference papers, Synthetic Jets: Fundamentals and Applications brings together in one book the fundamentals and applications of fluidic actuators.
Download or read book IUTAM Symposium on Flow Control and MEMS written by Jonathan F. Morrison and published by Springer Science & Business Media. This book was released on 2010-09-09 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Symposium brought together many of the world’s experts in fluid mechanics, microfabrication and control theory to discover the synergy that can lead to real advances and perhaps find ways in which collaborative projects may proceed. The high profile meeting was attended by keynote speakers who are leaders in their fields. A key driver was the improvement in flow efficiency to reduce drag, and thereby emissions arising from transport. About 65 papers were presented.
Download or read book Dynamic Large Eddy Simulation of Flow Interactions Due to Segmented Synthetic Jets in a Crossflow written by Eugene Michael McGlynn (Jr) and published by . This book was released on 2017 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Rings and Jets written by Daniel T. H. New and published by Springer. This book was released on 2015-03-26 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, recent developments in our understanding of fundamental vortex ring and jet dynamics will be discussed, with a view to shed light upon their near-field behaviour which underpins much of their far-field characteristics. The chapters provide up-to-date research findings by their respective experts and seek to link near-field flow physics of vortex ring and jet flows with end-applications in mind. Over the past decade, our knowledge on vortex ring and jet flows has grown by leaps and bounds, thanks to increasing use of high-fidelity, high-accuracy experimental techniques and numerical simulations. As such, we now have a much better appreciation and understanding on the initiation and near-field developments of vortex ring and jet flows under many varied initial and boundary conditions. Chapter 1 outlines the vortex ring pinch-off phenomenon and how it relates to the initial stages of jet formations and subsequent jet behaviour, while Chapter 2 takes a closer look at the behaviour resulting from vortex ring impingement upon solid boundaries and how the use of a porous surface alters the impingement process. Chapters 3 and 4 focus upon the formation of synthetic jets from vortex ring structures experimentally and numerically, the challenges in understanding the relationships between their generation parameters and how they can be utilized in flow separation control problems. Chapter 5 looks at the use of imposing selected nozzle trailing-edge modifications to effect changes upon the near-field dynamics associated with circular, noncircular and coaxial jets, with a view to control their mixing behaviour. And last but not least, Chapter 6 details the use of unique impinging jet configurations and how they may lend themselves towards greater understanding and operating efficacies in heat transfer problems. This book will be useful to postgraduate students and researchers alike who wish to get up to speed regarding the latest developments in vortex ring and jet flow behaviour and how their interesting flow dynamics may be put into good use in their intended applications.
Download or read book The Isolated Synthetic Jet in Crossflow written by Norman W. Schaeffler and published by BiblioGov. This book was released on 2013-08 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: An overview of the data acquisition, reduction, and uncertainty of experimental measurements made of the flowfield created by the interaction of an isolated synthetic jet and a turbulent boundary layer is presented. The experimental measurements were undertaken to serve as the second of three computational fluid dynamics validation databases for Active Flow Control. The validation databases were presented at the NASA Langley Research Center Workshop on CFD Validation of Synthetic Jets and Turbulent Separation Control in March, 2004. Detailed measurements were made to document the boundary conditions for the flow and also for the phase-averaged flowfield itself. Three component Laser-Doppler Velocimetry, 2-D Particle Image Velocimetry, and Stereo Particle Image Velocimetry were utilized to document the phase-averaged velocity field and the turbulent stresses.
Download or read book Manipulation and Control of Jets in Crossflow written by Ann R. Karagozian and published by Springer. This book was released on 2014-05-04 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamental Non-Reactive Jets in Crossflow and Other Jet Systems; Background on Modeling, Dynamical Systems, and Control; Reactive Jets in Crossflow and Multiphase Jets; Controlled Jets in Crossflow and Control via Jet Systems;
Download or read book Large eddy simulations of three dimensional synthetic jets in quiescent surroundings and in turbulent cross flow written by Don Ka Lam Wu and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthetic Jets Their Reduced Order Modeling and Applications to Flow Control written by O.K. Rediniotis and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Study written by Carlos Martínez Segarra and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A synthetic jet is formed by the oscillating movement of a membrane located inside a cavity. Such movement allows ambient fluid to be dragged inside and outside, hence producing a jet that is able to transfer both linear momentum and kinetic energy into the system without any external mass flux. It offers multiple interesting applications, the most relevant being active flow control and thermal control of electronic devices. This work focuses on the study of a discharge of a slotted synthetic jet actuator into an opened external medium. Numerical simulations using Large Eddy Simulations have been performed to analyze the jet behavior and vortex dynamics. Three mesh densities and two different cases based on the SJA governing parameters have been evaluated during the analysis. This study reveals that the advected vortex pair reaches a higher altitude before becoming the jet as the jet formation criteria becomes greater. This causes a bigger gradient on turbulent kinetic energy at higher altitudes which is closely related to the distance from the actuator orifice in which the vortex pair starts coalescing into the jet. Vortex penetration also increases with the jet formation criteria as such parameter is directly related to the actuator membrane deflection. A bigger jet formation criteria allows the membrane to deflect more, hence more fluid is dragged downstream resulting in the increase of the linear momentum contribution to the system. Such phenomenon straightaway affects the jet half-width which also increases with the jet formation criteria. This study also reveals that both cases share the same potential core which suggests that the ingestion and expulsion dynamics of a synthetic jet are independent of the jet formation criteria.
Download or read book Effect of the Jet Formation Criteria on Impinging Synthetic Jets written by Sergi Muñoz Moreno and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Synthetic Jet Actuators (SJA) are interesting devices that will have key roles in a wide range of engineering-relevant applications such as thermal management or active fow control. The synthetic jet is produced by the oscillatory movement of a membrane inside a cavity, thus causing the fluid to enter and leave the cavity through an orifice. Thus, resulting in a jet without the need of an external source of fluid. The current project is focused on the investigation of the fluid fluid flow and heat transfer performance of impinging synthetic jets. Specifically it aims to tackle one of the gaps identified in the literature: the lack of studies analyzing the synthetic jet (SJ) behaviours at different jet formation criteria (JFC). High fidelity wall-resolved Large Eddy Simulations is carried out at Reynolds of 50 and 500 for JFC of 1, 2, 3, 6 and 9 to solve the Navier-Stokes equations. A slotted/rectangular SJA configuration is studied. The jet is confined by two parallel isothermal plates with an imposed temperature difference, and impinges the hot plate located at the top of the domain from a certain distance of the actuator outlet orifice. In order to describe the actuator membrane movement, a model that makes use of Arbitrary Langrangian-Eulerian (ALE) formulation is used. The flow obtained in every simulation performed is three-dimensional for both Reynolds number 50 and 500 although coherent and laminar structures are clearly observed at some phases of the actuator cycles for the lowest Reynolds number. The external flow dynamics is characterised by two main re-circulations structures that are clearly visible during impingement of the jet into the hot wall. The velocity and temperature profiles have been computed at the actuator orifice for different time instants of the actuator cycle. The Reynolds number has a direct influence on the heat transfer capabilities of the synthetic jet but also the variation of the JFC as it has been observed that there is a range of JFC values at which the heat transfer performance is maximized. The results of these simulations will be valuable to develop cost-effective models of SJ and understand the difference between the flows at different SJ regimes.
Download or read book A Mesh Resolution Study for Large Eddy Simulation of Flow Interactions of a Finite span Synthetic Jet on an Airfoil written by Erik Larrabee and published by . This book was released on 2018 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time Accurate Aerodynamic Modeling of Synthetic Jets for Flow Control written by and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes a computational study undertaken to determine the aerodynamic effect of tiny unsteady synthetic jets as a means to provide the control authority needed to maneuver a spinning projectile at low subsonic speeds. Advanced Navier-Stokes computational techniques have been developed and used to obtain numerical solutions for the unsteady jet-interaction flow field at subsonic speeds and small angles of attack. Unsteady numerical results show the effect of the jet on the flow field and on the aerodynamic coefficients. The unsteady jet is shown to substantially alter the flow field both near the jet and the base region of the projectile that in turn affects the forces and moments even at zero degree angle of attack. The results have shown the potential of computational fluid dynamics to provide insight into the jet interaction flow fields and provided guidance as to the locations and sizes of the jets to generate the maximum control authority to maneuver a projectile to hit its target with precision.
Download or read book Numerical Techniques for Direct and Large Eddy Simulations written by Xi Jiang and published by CRC Press. This book was released on 2016-04-19 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compared to the traditional modeling of computational fluid dynamics, direct numerical simulation (DNS) and large-eddy simulation (LES) provide a very detailed solution of the flow field by offering enhanced capability in predicting the unsteady features of the flow field. In many cases, DNS can obtain results that are impossible using any other me
Download or read book Flow Control Techniques and Applications written by Jinjun Wang and published by Cambridge University Press. This book was released on 2019 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master the theory, applications and control mechanisms of flow control techniques.
Download or read book Large Eddy Simulation for Compressible Flows written by Eric Garnier and published by Springer Science & Business Media. This book was released on 2009-08-11 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book addresses both the fundamentals and the practical industrial applications of Large Eddy Simulation (LES) in order to bridge the gap between LES research and the growing need to use it in engineering modeling.
