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Article

A novel modeling approach for vortex generator jet flow separation control

Authors: von Stillfried, , Wallin, S.W., Johansson, A.V.J.
Document Type: Article
Pubstate: Published
Journal: 50th AIAA Aerospace Sciences Meeting, 9-12 January 2012, Nashville, TN, USA
Volume: AIAA 2012-0742  
Year: 2012

Abstract

This contribution describes the development and evaluation of a new statistical modeling approach for active vortex generator jet (VGJ) flow control. Previous experiments from Technical University Braunschweig, Germany, and a previous evaluation of the experiments by the authors showed that the resulting experimental vortices can be represented by Lamb-Oseen vortices. Based on that, an analytical expression is derived for the maximum circulation Gamma_max for the VGJ vortex in terms of the VGJ diameter Phi_VGJ, the jet to free stream velocity ratio lambda, as well as the VGJ pitch and skew angle alpha and beta, respectively. Gamma_max is used for describing the additional vortex velocity field that is originating from the VGJ. The idea behind the statistical modeling approach is that the generated vortices are represented by their averaged velocity correlations, or vortex stresses, that are in turn added to the transport equations in a Reynolds stres turbulence model. The spanwise averaged vortex stresses are derived by computing the spanwise averaged second-order statistics of the flow field. These results are compared to the spanwise averaged vortex stresses from experiments and corresponding results from fully resolved computational fluid dynamics investigations.