Download or read book Numerical Study of the Trailing Vortex of a Wing with Wing Tip Blowing written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-18 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Trailing vortices generated by lifting surfaces such as helicopter rotor blades, ship propellers, fixed wings, and canard control surfaces are known to be the source of noise, vibration, cavitation, degradation of performance, and other hazardous problems. Controlling these vortices is, therefore, of practical interest. The formation and behavior of the trailing vortices are studied in the present research. In addition, wing-tip blowing concepts employing axial blowing and spanwise blowing are studied to determine their effectiveness in controlling these vortices and their effects on the performance of the wing. The 3D, unsteady, thin-layer compressible Navier-Stokes equations are solved using a time-accurate, implicit, finite difference scheme that employs LU-ADI factorization. The wing-tip blowing is simulated using the actuator plane concept, thereby, not requiring resolution of the jet slot geometry. Furthermore, the solution blanking feature of the chimera scheme is used to simplify the parametric study procedure for the wing-tip blowing. Computed results are shown to compare favorably with experimental measurements. It is found that axial wing-tip blowing, although delaying the rolling-up of the trailing vortices and the near-field behavior of the flowfield, does not dissipate the circulation strength of the trailing vortex farther downstream. Spanwise wing-tip blowing has the effect of displacing the trailing vortices outboard and upward. The increased 'wing-span' due to the spanwise wing-tip blowing has the effect of lift augmentation on the wing and the strengthening of the trailing vortices. Secondary trailing vortices are created at high spanwise wing-tip blowing intensities. Lim, Hock-Bin Unspecified Center BLOWING; COMPUTERIZED SIMULATION; CONTROL SURFACES; FINITE DIFFERENCE THEORY; LIFT AUGMENTATION; NAVIER-STOKES EQUATION; ROTARY WINGS; ROTOR BLADES; SPANWISE BLOWING; VORTICES; WINGS; CANARD CONFIGURATIONS; CAVITATION FLOW; DIFFERENCE EQUATIONS; DISSI...
Download or read book Numerical Study of the Trailing Vortex of a Wing with Wing tip Blowing written by Hock-Bin Lim and published by . This book was released on 1994 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 602 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 Numerical Simulation of the Tip Vortex Off a Low aspect ratio Wing at Transonic Speed written by and published by . This book was released on 1984 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Exploratory Investigation of the Structure of the Tip Vortex of a Semispan Wing for Several Wing tip Modifications written by James Scheiman and published by . This book was released on 1970 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1995 with total page 1732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Vortex Sheet Immediately Behind an Aircraft Wing written by Barnes Warnock McCormick and published by . This book was released on 1965 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a wind tunnel and an in-flight experimental investigation of the trailing Vortex System immediately behind a finite wing are presented. Data are given on the vorticity distribution in the vortex sheet as it rolls up to form the trailing vortices. Information is given on the thickness of the vortex sheet, the size of the vortex core and the rate at which the vortex sheet rolls up as a function of the lift coefficient and Reynolds number. (Author).
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on with total page 1168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications Cumulative Index written by United States. Superintendent of Documents and published by . This book was released on 1976 with total page 1466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Commencement written by Stanford University and published by . This book was released on 1992 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of the Trailing Vortex System Generated by a Jet flapped Wing Operating at High Wing Lift Coefficients written by Barnes Warnock McCormick and published by . This book was released on 1970 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the investigation was to measure the geometry of the trailing vortex generated behind a jet-flapped wing. Such vortices can pose a serious hazard to aircraft that penetrate them. Previous investigations performed on conventional wings indicate that these vortices persist for some time and have maximum tangential velocities which increase linearly with the lift coefficient. As future aircraft may employ high lift devices such as jet-flapped wings, the vortices generated could be even stronger. Two semispan models of a jet-flapped wing were tested in a subsonic wing tunnel. Parameters varied during testing included the jet flap angle, angle of attack, aspect ratio, and jet momentum coefficient. Vortex measurements were obtained using a vortex meter which measured the rotational speed of the fluid within the vortex. Values obtained were numerically integrated to yield the tangential velocity and circulation distributed through the vortex. Experimental results indicate that the maximum tangential velocity increases to a maximum and then decreases with continually increasing jet blowing. At high values of jet blowing, the vortex was found to decay rapidly downstream. (Author).
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1994-09 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of a Wing Tip Vortex with Tip Blowing written by Jason R. Bettle and published by . This book was released on 2004 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2008 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1994 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation Into the Formation of Wing Tip Vortices written by J. Rom and published by . This book was released on 1974 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: A resume of the program of theoretical investigations into wing-tip vortex formation which is now in progress in the Department of Aeronautical Engineering at the Technion, Haifa, is given. The work is proceeding along two separate paths which it is hoped eventually to amalgamate. The first investigation consists of numerical work on the rolling up of the wing trailing vortex system when it is represented by discrete vortices according to a series of models of increasing complexity starting from the two-dimensional elliptic distribution as originally treated by Westwater and proceeding by stages through various lifting-line and lifting-surface models, including some exhibiting non-linear lift characteristics. The second project is a detailed investigation of the flow field near wing tips and wake edges, including thickness effects. It is felt that the precise flow field near wing tips and the wake edges must be understood if the rolling up and structure of the trailing-vortex cores is to be properly studied. (Author).
Download or read book Low Speed Aerodynamics written by Joseph Katz and published by Cambridge University Press. This book was released on 2001-02-05 with total page 636 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low-speed aerodynamics is important in the design and operation of aircraft flying at low Mach number, and ground and marine vehicles. This 2001 book offers a modern treatment of the subject, both the theory of inviscid, incompressible, and irrotational aerodynamics and the computational techniques now available to solve complex problems. A unique feature of the text is that the computational approach (from a single vortex element to a three-dimensional panel formulation) is interwoven throughout. Thus, the reader can learn about classical methods of the past, while also learning how to use numerical methods to solve real-world aerodynamic problems. This second edition has a new chapter on the laminar boundary layer (emphasis on the viscous-inviscid coupling), the latest versions of computational techniques, and additional coverage of interaction problems. It includes a systematic treatment of two-dimensional panel methods and a detailed presentation of computational techniques for three-dimensional and unsteady flows. With extensive illustrations and examples, this book will be useful for senior and beginning graduate-level courses, as well as a helpful reference tool for practising engineers.
