Computational Characterization of a Rectangular Vortex Generator on a Flat Plate for Different Vane Heights and Angles

Abstract

Vortex generators (VG) are passive flow control devices used for avoiding or delaying the separation of the boundary layer by bringing momentum from the higher layers of the fluid towards the surface. The Vortex generator usually has the same height as the local boundary layer thickness, and these Vortex generators can produce overload drag in some cases. The aim of the present study was to analyze the characteristics and path of the primary vortex produced by a single rectangular vortex generator on a flat plate for the incident angles of beta = 10 degrees, 15 degrees, 18 degrees and 20 degrees. A parametric study of the induced vortex was performed for six VG heights using Reynolds average Navier-Stokes equations at Reynodls number Re = 27,000 based on the local boundary layer thickness, using computational fluid dynamics techniques with OpenFOAM open-source code. In order to determine the vortex size, the so-called half-life radius was computed and compared with experimental data. The results showed a similar trend for all the studied vortex generator heights and incident angles with small variations for the vertical and the lateral paths. Additionally, 0.4H and 0.6H VG heights at incident angles of beta = 18 degrees and beta = 20 degrees showed the best performance in terms of vortex strength and generation of wall shear stress.