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Article

Evaluating and Parameterizing Round Vortex Generator Jet Experiments for Flow Control

Authors: von Stillfried, , Wallin, S.W., Johansson, A.V.J.
Document Type: Article
Pubstate: Published
Journal: AIAA Journal
Volume: 50(11)   2508-2524
Year: 2012

Abstract

Particle image velocimetry experiments on the application of vortex generator jets (VGJs) with single and pair configurations in a zero-pressure gradient flat plate boundary-layer flow have been carried out at the Technische Universitat Braunschweig. The experiments were analyzed at the Royal Institute of Technology by means of a velocity triple decomposition that enables the extraction of vortex velocity fields. The overall aim of this contribution is to identify and classify the influence of the different VGJ parameters on the generated vortex structures so that conclusions may be drawn for efficient flow separation control configurations. The spanwise-averaged second-order statistics (ViVj) over bar (y) of the vortex velocity field V-i(y, z) are computed in order to evaluate the influence of the VGJ parameters. It could be shown that the velocity ratio lambda and the skew angle beta have a major influence. Furthermore, the chosen single VGJ data are compared to corresponding VGJ pair results of a similar actuator setup. It was found that the VGJ pairs could be statistically well described by means of single VGJ vortices. Moreover, VGJ arrays should give very similar results for the configurations examined, facilitating VGJ modeling based on a statistical ansatz.