Download or read book The Vortex Lattice Method for the Rotor vortex Interaction Problem written by Raghuveera Padakannaya and published by . This book was released on 1974 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rotor blade-vortex interaction problem and the resulting impulsive airloads which generate undesirable noise levels are discussed. A numerical lifting surface method to predict unsteady aerodynamic forces induced on a finite aspect ratio rectangular wing by a straight, free vortex placed at an arbitrary angle in a subsonic incompressible free stream is developed first. Using a rigid wake assumption, the wake vortices are assumed to move downsteam with the free steam velocity. Unsteady load distributions are obtained which compare favorably with the results of planar lifting surface theory. The vortex lattice method has been extended to a single bladed rotor operating at high advance ratios and encountering a free vortex from a fixed wing upstream of the rotor. The predicted unsteady load distributions on the model rotor blade are generally in agreement with the experimental results. This method has also been extended to full scale rotor flight cases in which vortex induced loads near the tip of a rotor blade were indicated. In both the model and the full scale rotor blade airload calculations a flat planar wake was assumed which is a good approximation at large advance ratios because the downwash is small in comparison to the free stream at large advance ratios. The large fluctuations in the measured airloads near the tip of the rotor blade on the advance side is predicted closely by the vortex lattice method.

Download or read book The Vortex Lattice Method for the Rotor vortex Intercation Problem written by Raghuveera Padakannaya and published by . This book was released on 1974 with total page 129 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 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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).

Download or read book Unsteady Vortex Lattice Techniques Applied to Wake Formation and Performance of the Statically Thrusting Propeller written by Gerald Forrest Hall and published by . This book was released on 1975 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1975 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book T I S C A Technical Information Indexes written by United States. Naval Air Systems Command and published by . This book was released on 1975 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Contractor Report written by and published by . This book was released on 1988 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Information Indexes written by and published by . This book was released on 1975 with total page 126 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 1975 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vortex Methods Selected Papers Of The First International Conference On Vortex Methods written by Kyoji Kamemoto and published by World Scientific. This book was released on 2000-05-11 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vortex methods have been developed and applied to many kinds of flows related to various problems in wide engineering and scientific fields. The purpose of the First International conference on Vortex methods was to provide an opportunity for engineers and scientists to present their achievements, exchange ideas and discuss new developments in mathematical and physical modeling techniques and engineering applications of vortex methods.

Download or read book Journal of the American Helicopter Society written by American Helicopter Society and published by . This book was released on 1999 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the 5th International Symposium on Fluid Structure Interaction Aeroelasticity Flow Induced Vibration and Noise written by M. P. Paidoussis and published by . This book was released on 2002 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Proceedings of the 5th International Symposium on Fluid Structure Interactions Aeroelasticity Flow Induced Vibration and Noise written by M. P. Paidoussis and published by . This book was released on 2002 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vortex Dynamics and Vortex Methods written by Christopher Radcliff Anderson and published by American Mathematical Soc.. This book was released on 1991-12-23 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding vortex dynamics is the key to understanding much of fluid dynamics. For this reason, many researchers, using a great variety of different approaches--analytical, computational, and experimental--have studied the dynamics of vorticity. The AMS-SIAM Summer Seminar on Vortex Dynamics and Vortex Methods, held in June 1990 at the University of Washington in Seattle, brought together experts with a broad range of viewpoints and areas of specialization. This volume contains the proceedings from that seminar. The focus here is on the numerical computation of high Reynolds number incompressible flows. Also included is a smaller selection of important experimental results and analytic treatments. Many of the articles contain valuable introductory and survey material as well as open problems. Readers will appreciate this volume for its coverage of a wide variety of numerical, analytical, and experimental tools and for its treatment of interesting important discoveries made with these tools.

Download or read book Rotorcraft Aeromechanics written by Wayne Johnson and published by Cambridge University Press. This book was released on 2013-04-29 with total page 949 pages. Available in PDF, EPUB and Kindle. Book excerpt: A rotorcraft is a class of aircraft that uses large-diameter rotating wings to accomplish efficient vertical take-off and landing. The class encompasses helicopters of numerous configurations (single main rotor and tail rotor, tandem rotors, coaxial rotors), tilting proprotor aircraft, compound helicopters, and many other innovative configuration concepts. Aeromechanics covers much of what the rotorcraft engineer needs: performance, loads, vibration, stability, flight dynamics, and noise. These topics include many of the key performance attributes and the often-encountered problems in rotorcraft designs. This comprehensive book presents, in depth, what engineers need to know about modelling rotorcraft aeromechanics. The focus is on analysis, and calculated results are presented to illustrate analysis characteristics and rotor behaviour. The first third of the book is an introduction to rotorcraft aerodynamics, blade motion, and performance. The remainder of the book covers advanced topics in rotary wing aerodynamics and dynamics.