Dynamic Stall of a NACA 0012 Airfoil in Laminar Flow
Author : Sasi Kumar Digavalli
Publisher :
Page : 426 pages
File Size : 41,20 MB
Release : 1993
Category :
ISBN :
Author : Sasi Kumar Digavalli
Publisher :
Page : 426 pages
File Size : 41,20 MB
Release : 1993
Category :
ISBN :
Author : Kenneth W. McAlister
Publisher :
Page : 172 pages
File Size : 50,20 MB
Release : 1978
Category : Aerofoils
ISBN :
Author : Brandon James Pruski
Publisher :
Page : pages
File Size : 35,90 MB
Release : 2013
Category :
ISBN :
The leading edge flow structure of the NACA 0012 airfoil is experimentally investigated under dynamic stall conditions (M = 0.1; a = 16.7°, 22.4°, Rec = 1 x 106) using planar particle image velocimetry. The airfoil was dynamically pitched about the 1/4 chord at a reduced frequency, k = 0.1. As expected, on the upstroke the flow remains attached in the leading edge region above the static stall angle, whereas during downstroke, the flow remains separated below the static stall angle. A phase averaging procedure involving triple velocity decomposition in combination with the Hilbert transform enables the entire dynamic stall process to be visualized in phase space, with the added benefit of the complete phase space composed of numerous wing oscillations. The formation and complex evolution of the leading edge vortex is observed. This vortex is seen to grow, interact with surrounding vorticity, detach from the surface, and convect downstream. A statistical analysis coupled with instantaneous realizations results in the modification of the classical dynamic stall conceptual model, specifically related to the dynamics of the leading edge vortex. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/148372
Author : Mustafa Dindar
Publisher :
Page : pages
File Size : 42,78 MB
Release : 1992
Category :
ISBN :
Author : Tuncer Cebeci
Publisher :
Page : 22 pages
File Size : 24,43 MB
Release : 1983
Category :
ISBN :
The results of an investigation of boundary layers close to the stagnation point of an oscillating airfoil are reported. Two procedures for generating initial conditions - the characteristics-box scheme and a quasi-static approach - were investigated, and the quasi-static approach was shown to be appropriate provided the initial region was far from any flow separation. With initial conditions generated in this way, the unsteady boundary-layer equations were solved for the flow in the leading-edge region of a NACA 0012 airfoil oscillating from 0 degrees to 5 degrees. Results were obtained for both laminar and turbulent flow, and, in the latter case, the effect of transition was assessed by specifying its occurrence at different locations. The results demonstrate the validity of the numerical scheme and suggest that the procedures should be applied to calculation of the entire flow around oscillating airfoils. (Author).
Author :
Publisher :
Page : 172 pages
File Size : 26,88 MB
Release : 1978
Category : Science
ISBN :
Author : Kenneth W. McAlister
Publisher :
Page : 86 pages
File Size : 38,43 MB
Release : 1978
Category : Aerofoils
ISBN :
Author : Lawrence W. Carr
Publisher :
Page : 116 pages
File Size : 13,32 MB
Release : 1977
Category : Oscillating wings (Aerodynamics)
ISBN :
Author : Luiz M. Lourenco
Publisher :
Page : 86 pages
File Size : 11,6 MB
Release : 1993
Category : Aerofoils
ISBN :
Author : H. J. Gibeling
Publisher :
Page : 84 pages
File Size : 25,37 MB
Release : 1978
Category : Aerofoils
ISBN :