Estudio computacional de la variación del ángulo de incidencia en un generador de vórtices

Abstract

The separation of the boundary layer is generally an unwanted phenomenon in most of the fluid dynamic phenomena, for example, in aircraft wings, or through the rotor blades, and it involves the loss of lift which is causes a drag resistance and energy loss. Therefore, it is important to be able to find not only and efficient methods but also economical, to control the separation of the boundary layer. Flow separation can be achieved by using vortex generators (VG), which re-energize the inside of the boundary layer by generating longitudinal vortices that transfer energy from the external side of the boundary layer to the internal side, achieving suitable control of the detachment of the boundary layer. This research shows a computational study (CFD), inspired in passive vortex generators that are placed perpendicular to the surface at a different incidence angles settled in a flat plate. The flat plate has been previously simulated without the vortex generator, so that after having analyzed the development of the boundary layer, the vortex generator has been set up where the thickness of the boundary layer coincides with the height h = 250 mm. The computational simulations in an stable state, has been done at Reynolds number Re = 1350 and they have been carried out using Reynolds Averaged Navier-Stokes (RANS). The main objective of this work is to determine how far the analytical model developed by Velte et al. [1] represents the evolution of the wake downstream of a rectangular vortex generator on a plane plate at different incidence angles. The results show that the analytical model is able to follow the simulated flow trends and thereby, using this model, together with reliable computational simulations, it can reduce substantially the costs and time requirements of the parametric studies of vortex generators.