Download or read book Airfoil Interaction with an Impinging Vortex written by K. W. McAlister and published by . This book was released on 1984 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: THE TIP OF A FINITE-SPAN AIRFOIL WAS USED TO GENERATE A STREAMWISE VORTICAL FLOW, THE STRENGTH OF WHICH COULD BE VARIED BY CHANGING THE INCIDENCE OF THE AIRFOIL. The vortex that was generated traveled downstream and interacted with a second airfoil on which measurements of lift, drag, and pitching moment were made. The flow field, including the vortex core, was visualized in order to study the structural alterations to the vortex resulting from various levels of encounter with the downstream airfoil. These observations were also used to evaluate the accuracy of a theoretical model.
Download or read book Airfoil Interaction with an Impinging Vortex written by Kenneth W. McAlister and published by . This book was released on 1984 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Airfoil Interaction and Application of Methods for Digital Fringe Analysis written by G. E. Meier and published by . This book was released on 1986 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The interaction of convected vortices with different airfoils was investigated in a transonic duct and a shock tube flow. Different kinks of separation and secondary vortex generation have a governing influence on airfoil-vortex interaction. Steep sound waves propagating upstream are generated at the leading edge. A system for digital processing of flow interferograms has been developed.
Download or read book Unsteady Vortex Airfoil Interaction written by G. E. A. Meier and published by . This book was released on 1985 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Unsteady flow in the vicinity of an airfoil in a subsonic flow with strong vortices is investigated for a two-dimensional problem. This investigation concentrates on the interaction of the passing vortex, flow field with the steady flow field of the airfoil. Unsteady flow separation and generation of new vortices of the airfoil occurs depending on vortex strength and core path. Inviscid calculations of vortex path and sound generation are compared with the experimental results. The associated pressure waves have a strong directivity. The vortices used for the interaction experiments are generated by different vortex shedding cylinders in a stationary duct flow or by airfoils in the starting flow of a shock-tube. High speed interferometric flow recording and wall pressure measurement are the main experimental techniques.
Download or read book NASA Technical Paper written by and published by . This book was released on 1984 with total page 468 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 An Interaction Noise Between Vortex and Airfoil written by Jinzhang Feng and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Initial Circulation and Peak Vorticity Behavior of Vortices Shed from Airfoil Vortex Generators written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-20 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensive parametric study of vortices shed from airfoil vortex generators has been conducted to determine the dependence of initial vortex circulation and peak vorticity on elements of the airfoil geometry and impinging flow conditions. These elements include the airfoil angle of attack, chord length, span, aspect ratio, local boundary layer thickness, and free stream Mach number. In addition, the influence of airfoil-to-airfoil spacing on the circulation and peak vorticity has been examined for pairs of co-rotating and counter-rotating vortices. The vortex generators were symmetric airfoils having a NACA-0012 cross-sectional profile. These airfoils were mounted either in isolation, or in pairs, on the surface of a straight pipe. The turbulent boundary layer thickness to pipe radius ratio was about 17 percent. The circulation and peak vorticity data were derived from cross-plane velocity measurements acquired with a seven-hole probe at one chord-length downstream of the airfoil trailing edge location. The circulation is observed to be proportional to the free-stream Mach number, the angle-of-attack, and the span-to-boundary layer thickness ratio. With these parameters held constant, the circulation is observed to fall off in monotonic fashion with increasing airfoil aspect ratio. The peak vorticity is also observed to be proportional to the free-stream Mach number, the airfoil angle-of-attack, and the span-to-boundary layer thickness ratio. Unlike circulation, however, the peak vorticity is observed to increase with increasing aspect ratio, reaching a peak value at an aspect ratio of about 2.0 before falling off again at higher values of aspect ratio. Co-rotating vortices shed from closely spaced pairs of airfoils have values of circulation and peak vorticity under those values found for vortices shed from isolated airfoils of the same geometry. Conversely, counter-rotating vortices show enhanced values of circulation and peak vorticity when compared to values o
Download or read book Experimental Investigation of Three Dimensional Vortex Airfoil Interaction in A Supersonic Stream written by and published by . This book was released on 1995 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of the interaction between stream-wise vortices and a two-dimensional surface was conducted in a Mach 2.5 flow. The influence of oblique shock wave intensity on the inherently three-dimensional interaction was examined for vortices of variable strength. Planar laser sheet visualizations of the flowfield generated by the interaction at several distances downstream of the wedge leading edge were performed in order to gain an understanding of vortex behavior at distances further downstream. Results indicated that the interaction of a moderate strength vortex with an oblique shock wave leads to the formation of a steady separated shock structure upstream of the oblique shock front. Planar laser sheet visualization of the flowfield revealed an expansion of the vortex core in crossing a strong oblique shock front. The vortical structure was observed to persist along the entire chord of the shock generating wedge but was seen to diffuse with distances downstream of the wedge leading edge. Measurements of the vortex center above the wedge surface indicated that immediately downstream of the normal portion of the bulged-forward shock wave the vortex center was parallel to the direction of the free stream flow. (AN).
Download or read book The Modelling of Symmetric Airfoil Vortex Generators written by and published by . This book was released on 1996 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study is conducted to determine the dependence of vortex generator geometry and impinging flow conditions on shed vortex circulation and crossplane peak vorticity for one type of vortex generator. The vortex generator is a symmetric airfoil having a NACA 0012 cross-sectional profile. The vortex generators are mounted either in isolation or in a symmetric counter-rotating array configuation on the inside surface of a straight pipe. The turbulent boundary layer thickness-to-pipe radius ratio is 0.17. Circulation and peak vorticity data are derived from crossplane velocity measurements conducted at or about 1 chord downstream of the vortex generator trailing edge. Shed vortex circulation is observed to be proportional to Mach number, angle of attack and space to boundary-layer thickness. With these parameters held constant, circulation is observed to fall off in monotonic fashion with increasing airfoil aspect ratio. Shed vortex peak vorticity is also observed to be proportional to the aforementioned parameters. Unlike circulation, however, peak vorticity is observed to increase with increasing aspect ratio.
Download or read book Numerical Simulation of the Interaction of a Vortex with Stationary Airfoil in Transonic Flow written by G. R. Srinivasan and published by . This book was released on 1984 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A perturbation form of an implicit conservative, noniterative numerical algorithm for the two-dimensional thin layer Navier-Stokes and Euler equations is used to computer the interaction flow field of a vortex with stationary airfoil. A Lamb-like analytical vortex having a finite core is chosen to interact with a thick (NACA 0012) and a thin (NACA 64A006) airfoil independently in transonic flow. Two different configurations of vortex interaction are studied: (1) when the vortex is fixed at one location in the flow field; and (2) when the vortex is convecting past the airfoil at free stream velocity. Parallel computations of this interacting flow field are also done using a version of the Transonic Small Disturbance Code (ATRAN2). A special treatment of the leading edge region for thin airfoils is included in this code. With this, the three methods gave qualitatively similar results for the weaker interactions considered in this study. However, the strongest interactions considered proved to be beyond the capabilities of the small disturbance code.
Download or read book Initial Circulation and Peak Vorticity Behavior of Vortices Shed from Airfoil Vortex Generators written by and published by . This book was released on 2001 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Flow Visualization Study of a Vortex wing Interaction written by and published by . This book was released on 1984 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Dynamics Theories and Applications written by Zambri Harun and published by BoD – Books on Demand. This book was released on 2020-12-09 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book comprises of different areas in which vortex dynamics is important, its generation, evolution, interactions with other motions, and finally the ways it can be controlled. Vortex characteristics are important in many aspects of our lives, from blood circulation in the arteries to the high-speed jet. Flow control and manipulation of vortices have been used to reduce drag for large tankers resulting in billions of dollars in savings. An effective smoke management system must be put in place for critical areas to ensure the safety of people, for example in a very large shopping complex or a large airport. Advanced computational and cloud-computing facilities have contributed significantly to large-scale simulation projects. Therefore, validations could be performed for larger windows of study so that it can now cover the entire e.g. central business district (CBD) for urban heat island (UHI) study or land-ocean interactions.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Acoustics of Fluid Structure Interactions written by M. S. Howe and published by Cambridge University Press. This book was released on 1998-08-13 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: A reference for analytical methods for modelling acoustic problems, a repository of known results and methods in the theory of aerodynamic sound, and a graduate-level textbook.
Download or read book Numerical Investigation of Parallel Airfoil vortex Interaction Using Large eddy Simulation written by Frederic N. Felton and published by . This book was released on 2003 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
