Control of shock-induced separation using air-jet vortex generators

Abstract

Shock-induced separation leads to highly unsteady flow fields and has strong detrimental effects on the aerodynamic behavior and performance of numerous aerospace-engineering applications. To reduce these effects, separation control is required. A very promising approach is the use of rows of air-jet vortex generators (AJVGs), where small spanwise-inclined jets of air injected into the flow increase the momentum transfer within the boundary layer and thus make it less prone to separation. A large number of parameters influence the control effectiveness of AJVGs, amongst them geometrical parameters, such as the orifice shape, orifice size, and injection-pipe length; flow parameters, including the (steady or forced) injection pressure; and the array arrangement. The talk will provide an overview on the relevant control parameters and their respective influences, also comparing AJVGs with classical mechanical vortex generators. Recent experimental and numerical studies at RWTH Aachen University provide a rich experimental-numerical data set, which we have jointly analyzed and interpreted using statistical methods and modal analysis with dynamic-mode decomposition, amongst other techniques. On the basis of these results, the physical mechanisms and underlying flow dynamics governing the control effect of AJVGs, as well as the observed flow phenomena and control effects, will be presented and discussed. Image credit: [Thomas Stephan (Unsplash)](https://unsplash.com/photos/white-smoke-on-black-background-KLQg7ugoqms).

Authors 1

1. Anne-Marie Schreyer corresponding Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University