Helicopter Rotor Wake Geometry and Its Influence in Forward Flight

Helicopter Rotor Wake Geometry and Its Influence in Forward Flight PDF Author: T. Alan Egolf
Publisher:
ISBN:
Category : Helicopters
Languages : en
Pages :

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Helicopter Rotor Wake Geometry and Its Influence in Forward Flight

Helicopter Rotor Wake Geometry and Its Influence in Forward Flight PDF Author: T. Alan Egolf
Publisher:
ISBN:
Category : Helicopters
Languages : en
Pages :

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Book Description


Helicopter Rotor Wake Geometry and Its Influence in Forward Flight. Volume 1: Generalized Wake Geometry and Wake Effect on Rotor Airloads and Performance

Helicopter Rotor Wake Geometry and Its Influence in Forward Flight. Volume 1: Generalized Wake Geometry and Wake Effect on Rotor Airloads and Performance PDF Author: T. A. Egolf
Publisher:
ISBN:
Category :
Languages : en
Pages : 228

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Book Description
An analytic investigation to generalize wake geometry of a helicopter rotor in steady level forward flight and to demonstrate the influence of wake deformation in the prediction of rotor airloads and performance is described. Volume 1 presents a first level generalized wake model based on theoretically predicted tip vortex geometries for a selected representative blade design. The tip vortex distortions are generalized in equation form as displacements from the classical undistorted tip vortex geometry in terms of vortex age, blade azimuth, rotor advance ratio, thrust coefficient, and number of blades. These equations were programmed to provide distorted wake coordinates at very low cost for use in rotor airflow and airloads prediction analyses. The sensitivity of predicted rotor airloads, performance, and blade bending moments to the modeling of the tip vortex distortion are demonstrated for low to moderately high advance ratios for a representative rotor and the H-34 rotor. Comparisons with H-34 rotor test data demonstrate the effects of the classical, predicted distorted, and the newly developed generalized wake models on airloads and blade bending moments. Use of distorted wake models results in the occurrence of numerous blade-vortex interactions on the forward and lateral sides of the rotor disk. The significance of these interactions is related to the number and degree of proximity to the blades of the tip vortices. The correlation obtained with the distorted wake models (generalized and predicted) is encouraging.

Helicopter Rotor Wake Geometry and Its Influence in Forward Flight. Volume 2: Wake Geometry Charts

Helicopter Rotor Wake Geometry and Its Influence in Forward Flight. Volume 2: Wake Geometry Charts PDF Author: T. Alan Egolf
Publisher:
ISBN:
Category :
Languages : en
Pages : 212

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Rotorcraft Aeromechanics

Rotorcraft Aeromechanics PDF Author: Wayne Johnson
Publisher: Cambridge University Press
ISBN: 1107355281
Category : Technology & Engineering
Languages : en
Pages : 949

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Book Description
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.

Principles of Helicopter Aerodynamics with CD Extra

Principles of Helicopter Aerodynamics with CD Extra PDF Author: Gordon J. Leishman
Publisher: Cambridge University Press
ISBN: 9780521858601
Category : Science
Languages : en
Pages : 860

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Book Description
Written by an internationally recognized teacher and researcher, this book provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft such as tilt rotors and autogiros. The text begins with a unique technical history of helicopter flight, and then covers basic methods of rotor aerodynamic analysis, and related issues associated with the performance of the helicopter and its aerodynamic design. It goes on to cover more advanced topics in helicopter aerodynamics, including airfoil flows, unsteady aerodynamics, dynamic stall, and rotor wakes, and rotor-airframe aerodynamic interactions, with final chapters on autogiros and advanced methods of helicopter aerodynamic analysis. Extensively illustrated throughout, each chapter includes a set of homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thoroughly revised and updated text on rotating-wing aerodynamics.

Experimental Evaluation of a Flat Wake Theory for Predicting Rotor Inflow-wake Velocities

Experimental Evaluation of a Flat Wake Theory for Predicting Rotor Inflow-wake Velocities PDF Author: John C. Wilson
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 62

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Principles of Helicopter Aerodynamics

Principles of Helicopter Aerodynamics PDF Author: J. Gordon Leishman
Publisher: Cambridge University Press
ISBN: 9780521523967
Category : Medical
Languages : en
Pages : 544

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Book Description
Helicopters are highly capable and useful rotating-wing aircraft with roles that encompass a variety of civilian and military applications. Their usefulness lies in their unique ability to take off and land vertically, to hover stationary relative to the ground, and to fly forward, backward, or sideways. These unique flying qualities, however, come at a high cost including complex aerodynamic problems, significant vibrations, high levels of noise, and relatively large power requirements compared to fixed-wing aircraft. This book, written by an internationally recognized expert, provides a thorough, modern treatment of the aerodynamic principles of helicopters and other rotating-wing vertical lift aircraft. Every chapter is extensively illustrated and concludes with a bibliography and homework problems. Advanced undergraduate and graduate students, practising engineers, and researchers will welcome this thorough and up-to-date text on rotating-wing aerodynamics.

Compressible, Unsteady Lifting-surface Theory for a Helicopter Rotor in Forward Flight

Compressible, Unsteady Lifting-surface Theory for a Helicopter Rotor in Forward Flight PDF Author: Harry L. Runyan
Publisher:
ISBN:
Category : Helicopters
Languages : en
Pages : 28

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Rotorcraft Dynamics 1984

Rotorcraft Dynamics 1984 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 518

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Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1252

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Book Description