Author : Lamiae Taoudi
Publisher :
ISBN 13 :
Total Pages : 102 pages
Book Rating : 4.:/5 (96 download)
Book Synopsis Control of Görtler Vortices by Means of Wall Deformations and Blowing/suction by : Lamiae Taoudi
Download or read book Control of Görtler Vortices by Means of Wall Deformations and Blowing/suction written by Lamiae Taoudi and published by . This book was released on 2016 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: Görtler vortices evolve in boundary layers over concave surfaces as a result of the imbalance between centrifugal forces and radial pressure gradients. Depending on various geometrical and free-stream flow conditions, these instabilities may lead to secondary instabilities and early transition to turbulence. In this thesis, a control algorithm based on the boundary region equations is applied to reduce the strength of the Görtler instabilities by controlling the energy of the fully developed vortices, using either local wall deformations or blowing/suction at the wall. A proportional-integral control scheme is utilized to deform the wall or to provide transpiration velocity, where the inputs are either the wall-normal or streamwise velocity components in a plane that is parallel to the wall. The results show that the control based on wall deformation using wall-normal velocity components is more effective in tempering the vortex during its streamwise growth by almost one or two orders of magnitude.