Experimental Study of Half-Delta Wing Vortex Generator for Flow Separation Control

Abstract

This paper describes an experimental study of the effects of passive half-delta wing vortex generators on a backward-facingramp flow.Fourmodelsofvortexgeneratorswithaspectratiosof0.4,0.8,and1.6weretestedinan open-circuit wind tunnel. The vortex generators were placed upstream of the backward-facing ramp where their heights were 24 and 48% of the boundary-layer thickness. Flow visualization and velocity measurements were conducted using a particle image velocimetry system. The results showed that an array of vortex generators with an aspect ratio of 1.6 had the highest efficiency in reducing the flow separation region. Nomenclature c = vortex generator chord length c=h = vortex generator chord length to vortex generator height ratio d = vortex generator spacing from trailing edge to trailing edge d=h = vortex generator trailing-edge spacing to vortex generator height ratio h = vortex generator height h=� = vortex generator height to boundary-layer thickness ratio � = vortex generator angle of incidence � = boundary-layer thickness � = displacement thickness � = momentum thickness