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Full Potential Modeling Of Blade Vortex Interactions
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Book Synopsis Full-Potential Modeling of Blade-Vortex Interactions by : Henry E. Jones
Download or read book Full-Potential Modeling of Blade-Vortex Interactions written by Henry E. Jones and published by . This book was released on 1997 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of the full-potential modeling of a blade-vortex interaction was made. A primary goal of this study was to investigate the effectiveness of the various methods of modeling the vortex. The model problem restricts the interaction to that of an infinite wing with an infinite line vortex moving parallel to its leading edge. This problem provides a convenient testing ground for the various methods of modeling the vortex while retaining the essential physics of the full three-dimensional interaction. A full-potential algorithm specifically tailored to solve the blade-vortex interaction (BVI) was developed to solve this problem. The basic algorithm was modified to include the effect of a vortex passing near the airfoil. Four different methods of modeling the vortex were used: (1) the angle-of-attack methods, (2) the lifting-surface method, (3) the branch-cut method, and (4) the split-potential method. A side-by-side comparison of the four models was conducted. these comparisons included comparing generated velocity fields, a subcritical interaction, and a critical interaction. The subcritical and critical interactions are compared with experimentally generate results. The split-potential model was used to make a survey of some of the more critical parameters which affect the BVI.
Book Synopsis Full-potential Modeling of Blade-vortex Interactions by : Henry Edward Jones
Download or read book Full-potential Modeling of Blade-vortex Interactions written by Henry Edward Jones and published by . This book was released on 1986 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Effects of Vortex Modeling on Blade-Vortex Interaction Noise Prediction by :
Download or read book The Effects of Vortex Modeling on Blade-Vortex Interaction Noise Prediction written by and published by . This book was released on 1995 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of a blade vortex interaction noise prediction scheme, based on CAMRAD/JA, FPR and RAPP, quantifies the effects of errors and assumptions in the modeling of the helicopter's shed vortex on the acoustic predictions. CAMRAD/JA computes the wake geometry and inflow angles that are used in FPR to solve for the aerodynamic surface pressures. RAPP uses these surface pressures to predict the acoustic pressure. Both CAMRAD/JA and FPR utilize the Biot-Savart Law to determine the influence of the vortical velocities on the blade loading and both codes use an algebraic vortex model for the solid body rotation of the vortex core. Large changes in the specification of the vortex core size do not change the inplane wake geometry calculated by CAMRAD/JA and only slighty affect the out-of-plane wake geometry. However, the aerodynamic surface pressure calculated by FPR changes in both magnitude and character with small changes to the core size used by the FPR calculations. This in turn affects the acoustic predictions. Shifting the CAMRAD/JA wake geometry away from the rotor plane by 1/4 chord produces drastic changes in the acoustic predictions indicating that the prediction of acoustic pressure is extremely sensitive to the miss distance between the vortex and the blade and that this distance must be calulated as accurately as possible for acceptable noise predictions. The inclusion or exclusion of a vortex in the FPR-RAPP calculation allows for the determination of the relative importance of that vortex as a BVI noise source. (AN).
Book Synopsis Discrete Vortex Modeling of a Blade-vortex Interaction by : Piergiovanni Renzoni
Download or read book Discrete Vortex Modeling of a Blade-vortex Interaction written by Piergiovanni Renzoni and published by . This book was released on 1987 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis The Numerical Simulation of Compressible Blade Vortex Interaction by : Amer Hussain Sheikh
Download or read book The Numerical Simulation of Compressible Blade Vortex Interaction written by Amer Hussain Sheikh and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis New Technique for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers by : Earl R. Booth
Download or read book New Technique for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers written by Earl R. Booth and published by . This book was released on 1986 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis New Techniques for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers by :
Download or read book New Techniques for Experimental Generation of Two-dimensional Blade-vortex Interaction at Low Reynolds Numbers written by and published by . This book was released on 1986 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Foundations of the Blade-Vortex Interaction Problem: Structure and Behavior of Travelling Compressible Vortices by : Daniel Bershader
Download or read book Foundations of the Blade-Vortex Interaction Problem: Structure and Behavior of Travelling Compressible Vortices written by Daniel Bershader and published by . This book was released on 1988 with total page 191 pages. Available in PDF, EPUB and Kindle. Book excerpt: The structure of a compressible free vortex has been analyzed while undergoing convection in a quasi-uniform stream flow. Holographic interferograms several reveal radial density profiles of the vortex at different stages of its development during convection. A general mathematical expression is found which closely describes the distribution of density inside the vortex. By use of experimental data and the governing equations in an empirical/theoretical analysis, an extended physical description of the vortex is developed. The time behavior of the density, determined from the experiments, allows the solution of the Continuity Equation and a distribution of the radial component of fluid velocity relative to the vortex center is obtained. The density information, supplemented by an independent determination of pressure is the used in the Radial Momentum Equation to obtain a distribution of the circumferential component of fluid velocity relative to the vortex center, thus completing the description of the radial dependence of the velocities inside the vortex. Furthermore, the calculated velocities are used to evaluate the magnitudes of the convective and diffusive terms of the Angular Momentum Equation, thus providing insight into the question of the relative effects of compressibility and viscosity on the internal structure and behavior of the vortex in terms of the distribution and transport of angular momentum. Keywords: Blade vortex interaction, Rotary wing flight, Rotor wake, Compressible free vortex. (aw).
Book Synopsis Two- and Three-dimensional Blade Vortex Interactions by :
Download or read book Two- and Three-dimensional Blade Vortex Interactions written by and published by . This book was released on 1990 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Experimental Investigation of the Parallel Blade-vortex Interaction by :
Download or read book An Experimental Investigation of the Parallel Blade-vortex Interaction written by and published by . This book was released on 1984 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Computational Study of High Speed Blade-vortex Interaction by : Erkan Yildirim
Download or read book Computational Study of High Speed Blade-vortex Interaction written by Erkan Yildirim and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents inviscid compressible simulations for the orthogonal blade-vortex interaction. A numerical model between the tail rotor of a helicopter and the trailing vortex system formed by the main rotor blades is assumed. The study takes a 'building-block' approach to investigating this problem. Firstly, the impulsive instantaneous blocking of the axial core flow by a flat plate is considered. In the second step, the three-dimensional gradual cutting of the vortex by a sharp flat-plate that moves at a finite speed through the vortex is performed. Finally the chopping of the vortex by a blunt leading edge aerofoil, which incorporates both the blocking effect and also the stretching and distortion of the vortex lines is studied. The solutions reveal that the compressibility effects are strong when the axial core flow of the vortex is impulsively blocked. This generates a weak shock-expansion structure propagating along the vortex core on opposite sides of the cutting surface. The shock and expansion waves are identified as the prominent acoustic signatures in the interaction. In a simplified, two-dimensional axisymmetric model, the modelling of the physical evolution of the vortex, including the evolution of the complex vortical structures that controls the vortex core size near the cutting surface, are studied. Furthermore, the three dimensional simulations revealed that there is a secondary and a tertiary noise sources due to compressibility effects at the blade leading edge and due to the shock-vortex interaction taking place on the blade, which is exposed to a transonic free-stream flow.
Book Synopsis Aerodynamic Aspects of Blade-vortex Interaction (BVI) by : Chee Tung
Download or read book Aerodynamic Aspects of Blade-vortex Interaction (BVI) written by Chee Tung and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis An Adaptive Mesh Method for the Simulation of Blade Vortex Interaction by : Kyu-Sup Kim
Download or read book An Adaptive Mesh Method for the Simulation of Blade Vortex Interaction written by Kyu-Sup Kim and published by . This book was released on 1998 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781722402327 Total Pages :94 pages Book Rating :4.4/5 (23 download)
Book Synopsis Flow Visualizations of Perpendicular Blade Vortex Interactions by : National Aeronautics and Space Administration (NASA)
Download or read book Flow Visualizations of Perpendicular Blade Vortex Interactions written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Helium bubble flow visualizations have been performed to study perpendicular interaction of a turbulent trailing vortex and a rectangular wing in the Virginia Tech Stability Tunnel. Many combinations of vortex strength, vortex-blade separation (Z(sub s)) and blade angle of attack were studied. Photographs of representative cases are presented. A range of phenomena were observed. For Z(sub s) greater than a few percent chord the vortex is deflected as it passes the blade under the influence of the local streamline curvature and its image in the blade. Initially the interaction appears to have no influence on the core. Downstream, however, the vortex core begins to diffuse and grow, presumably as a consequence of its interaction with the blade wake. The magnitude of these effects increases with reduction in Z(sub s). For Z(sub s) near zero the form of the interaction changes and becomes dependent on the vortex strength. For lower strengths the vortex appears to split into two filaments on the leading edge of the blade, one passing on the pressure and one passing on the suction side. At higher strengths the vortex bursts in the vicinity of the leading edge. In either case the core of its remnants then rapidly diffuse with distance downstream. Increase in Reynolds number did not qualitatively affect the flow apart from decreasing the amplitude of the small low-frequency wandering motions of the vortex. Changes in wing tip geometry and boundary layer trip had very little effect. Rife, Michael C. and Davenport, William J. Unspecified Center...
Book Synopsis The numerical simulation of blade-vortex interaction by : Amer Hussain Sheikh
Download or read book The numerical simulation of blade-vortex interaction written by Amer Hussain Sheikh and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Three-dimensional Model of Low-speed Blade-vortex Interaction by : F. N. Coton
Download or read book A Three-dimensional Model of Low-speed Blade-vortex Interaction written by F. N. Coton and published by . This book was released on 1994 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Blade Vortex Interaction and Its Alleviation Using Passive and Active Control Approaches by : Marino De Terlizzi
Download or read book Blade Vortex Interaction and Its Alleviation Using Passive and Active Control Approaches written by Marino De Terlizzi and published by . This book was released on 1999 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: