Theoretical and numerical studies of oscillating airfoils

Computational prediction of airfoil dynamic stall

“…Fully turbulent solutions at Re"1;10 for a sinusoidal oscillation of a NACA-0012 airfoil with (t)"15°#10°sin( t) and reduced frequencies k"0.1, 0.15 and 0.25 were obtained in Ref. (149), using the computationally efficient procedure of Refs. (164, 165).…”

A Vorticity-Based Method for Incompressible Unsteady Viscous Flows

“…In the pioneering works of Wu and coworkers, a finite difference scheme was used to solve the vorticity transport equation in the transformed complex plane. The integral equation for the velocity was solved by using finite Fourier series expansions of the field variables at each circular ring of the O-grid and partially evaluated analytically [33,35]. Meanwhile, to reduce the possibility of numerical diffusion in the grid-based method, the Lagrangian discrete vortex method has been developed and applied, notably by Chorin [8], Leonard [21,22], Sarpkaya [28], and more recently among others by Spalart [32], Koumoutsakos and Leonard [19], and Lin et al [24].…”

Analysis of horizontal axis wind turbine blade using CFD

“…Also, rotor wake effects were accounted for by applying a correction to the geometric angle of attack of the blades. Later, a rather original approach was tried by Tuncer et al (1990). In particular, the authors used a velocity-vorticity formulation of the Navier -Stokes equations containing a vorticity transport equation, which is solved in the viscous flow zone, and an integral equation for the velocity.…”