Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781724741875
Category :
Languages : en
Pages : 32
Book Description
The general features of dynamic stall on oscillating airfoils are explained in terms of the vortex shedding phenomenon, and the important differences between static stall, light dynamic stall, and deep stall are described. An overview of experimentation and prediction techniques is given. Mccroskey, W. J. Ames Research Center NASA-TM-81264, A-8464
The Phenomenon of Dynamic Stall. [vortex Shedding Phenomenon on Oscillating Airfoils]
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781724741875
Category :
Languages : en
Pages : 32
Book Description
The general features of dynamic stall on oscillating airfoils are explained in terms of the vortex shedding phenomenon, and the important differences between static stall, light dynamic stall, and deep stall are described. An overview of experimentation and prediction techniques is given. Mccroskey, W. J. Ames Research Center NASA-TM-81264, A-8464
Publisher: Createspace Independent Publishing Platform
ISBN: 9781724741875
Category :
Languages : en
Pages : 32
Book Description
The general features of dynamic stall on oscillating airfoils are explained in terms of the vortex shedding phenomenon, and the important differences between static stall, light dynamic stall, and deep stall are described. An overview of experimentation and prediction techniques is given. Mccroskey, W. J. Ames Research Center NASA-TM-81264, A-8464
The Phenomenon of Dynamic Stall
Author: W. J. McCroskey
Publisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Stall and its consequences are fundamentally important to the design and operation of flight vehicles. A certain degree of unsteadiness always accompanies the flow over an airfoil or other streamlined body at high angle of attack, but the stall of a lifting surface undergoing unsteady motion is even more complex than static stall. Dynamic stall remains a major unsolved problem with a variety of current applications in aeronautics, hydrodynamics, and wind engineering. This report summarizes the main physical features of the phenomenon and the attempts that have been made to predict it. The information presented is drawn mainly from recent review articles and investigations by the author and his colleagues. Since a large fraction of the existing knowledge has come from experimental research, the details of dynamic stall are discussed principally in physical terms.
Publisher:
ISBN:
Category :
Languages : en
Pages : 38
Book Description
Stall and its consequences are fundamentally important to the design and operation of flight vehicles. A certain degree of unsteadiness always accompanies the flow over an airfoil or other streamlined body at high angle of attack, but the stall of a lifting surface undergoing unsteady motion is even more complex than static stall. Dynamic stall remains a major unsolved problem with a variety of current applications in aeronautics, hydrodynamics, and wind engineering. This report summarizes the main physical features of the phenomenon and the attempts that have been made to predict it. The information presented is drawn mainly from recent review articles and investigations by the author and his colleagues. Since a large fraction of the existing knowledge has come from experimental research, the details of dynamic stall are discussed principally in physical terms.
A Study of Dynamic Stall Vortex Development Using Two-Dimensional Data from the AFDD Oscillating Wing Experiment
Author: Myung J. Rhee
Publisher:
ISBN:
Category : Aerodynamic load
Languages : en
Pages : 112
Book Description
The purpose of this study is to examine the previously unpublished instantaneous pressure data of the Aeroflightdynamics Directorate Two-Dimensional (2D) and Three-Dimensional (3D) Oscillating Wing Experiment to better understand the process of dynamic stall vortex development on the NACA 0015 airfoil. This report presents representative 2D instantaneous pressure data for the upper and lower surfaces of the airfoil at various chordwise locations obtained at specific angles of attack during upstroke and downstroke cycles. Furthermore, the report contains a complete set of plots of instantaneous pressure distributions for the upper surface for all the 2D data sets obtained in the experiment. First, the lift, drag and pitching moment data of various testing conditions are reviewed and analyzed to classify the data both with and without a boundary layer trip into "no stall," "moderate stall," and "deep stall" data. Next, instantaneous pressure distributions on the upper surface of the airfoil are examined for the study of vortex development. The lift and pitching moment data are analyzed to document the dynamic overshoot which delays the development of the stall on the airfoil. Next, the range of angles of attack are selected where the lift and pitching moment data shows significant changes from unsteady flow behavior daring oscillation cycles. Furthermore, based on the unsteady flow characteristics found in each classification of dynamic stall, analysis is continued to identify the conditions where the reduced frequency clearly affects the unsteady flow behavior of the airfoil during the oscillation. This can result in a change of the dynamic stall classification of the airfoil response under various unsteady flow conditions. These conditions are discussed in detail in the comparative studies.
Publisher:
ISBN:
Category : Aerodynamic load
Languages : en
Pages : 112
Book Description
The purpose of this study is to examine the previously unpublished instantaneous pressure data of the Aeroflightdynamics Directorate Two-Dimensional (2D) and Three-Dimensional (3D) Oscillating Wing Experiment to better understand the process of dynamic stall vortex development on the NACA 0015 airfoil. This report presents representative 2D instantaneous pressure data for the upper and lower surfaces of the airfoil at various chordwise locations obtained at specific angles of attack during upstroke and downstroke cycles. Furthermore, the report contains a complete set of plots of instantaneous pressure distributions for the upper surface for all the 2D data sets obtained in the experiment. First, the lift, drag and pitching moment data of various testing conditions are reviewed and analyzed to classify the data both with and without a boundary layer trip into "no stall," "moderate stall," and "deep stall" data. Next, instantaneous pressure distributions on the upper surface of the airfoil are examined for the study of vortex development. The lift and pitching moment data are analyzed to document the dynamic overshoot which delays the development of the stall on the airfoil. Next, the range of angles of attack are selected where the lift and pitching moment data shows significant changes from unsteady flow behavior daring oscillation cycles. Furthermore, based on the unsteady flow characteristics found in each classification of dynamic stall, analysis is continued to identify the conditions where the reduced frequency clearly affects the unsteady flow behavior of the airfoil during the oscillation. This can result in a change of the dynamic stall classification of the airfoil response under various unsteady flow conditions. These conditions are discussed in detail in the comparative studies.
Dynamic Stall of Small Wind Systems
Author: Richard B. Noll
Publisher:
ISBN:
Category : Wind power
Languages : en
Pages : 300
Book Description
Publisher:
ISBN:
Category : Wind power
Languages : en
Pages : 300
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 456
Book Description
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.
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 456
Book Description
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.
Principles of Helicopter Aerodynamics
Author: J. Gordon Leishman
Publisher: Cambridge University Press
ISBN: 9780521523967
Category : Medical
Languages : en
Pages : 544
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.
Publisher: Cambridge University Press
ISBN: 9780521523967
Category : Medical
Languages : en
Pages : 544
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.
Transport Phenomena in Rotating Machinery
Author: J. H. Kim
Publisher: CRC Press
ISBN: 9781560320135
Category : Science
Languages : en
Pages : 572
Book Description
Completing the authoritative coverage begun in Dynamics of Rotating Machinery, this text offers 36 current chapters focusing on the areas of fluid flow, heat transfer, multiple flow, cavitation and design.
Publisher: CRC Press
ISBN: 9781560320135
Category : Science
Languages : en
Pages : 572
Book Description
Completing the authoritative coverage begun in Dynamics of Rotating Machinery, this text offers 36 current chapters focusing on the areas of fluid flow, heat transfer, multiple flow, cavitation and design.
Computational Methods and Experimental Measurements XV
Author: G. M. Carlomagno
Publisher: WIT Press
ISBN: 1845645405
Category : Mathematics
Languages : en
Pages : 737
Book Description
Containing edited versions of most of the papers presented at the Fifteenth International Conference on Computational Methods and Experimental Measurements, this book reviews the latest work on these two approaches, and the interaction between them.
Publisher: WIT Press
ISBN: 1845645405
Category : Mathematics
Languages : en
Pages : 737
Book Description
Containing edited versions of most of the papers presented at the Fifteenth International Conference on Computational Methods and Experimental Measurements, this book reviews the latest work on these two approaches, and the interaction between them.
Analysis of Computed Flow Parameters for a Set of Sudden Stalls in Low-speed Two-dimensional Flow
Author: William T. Evans
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 710
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 710
Book Description