ISBN 9783843926935

978-3-8439-2693-5, Reihe Ingenieurwissenschaften

Holger Kurz
Towards laminar flow on a swept wing: Direct numerical simulation of discrete-roughness receptivity and turbulence tripping

153 Seiten, Dissertation Universität Stuttgart (2016), Softcover, A5

Zusammenfassung / Abstract

A detailed DNS study on the effects of a spanwise row of discrete roughness elements in a three-dimensional boundary layer on a swept wing in the high subsonic flow range has been performed for two flow regimes. The first part of this work addresses the receptivity to shallow circular roughness elements with a focus on scrutinizing the “linearity” often found in previous studies. The second part concentrates on finite-height roughness elements and their ability to trigger transition to turbulence directly. In this context, a 3D global stability analysis for the temporally-stabilized flow past a quasi-critical and a critical roughness element has been performed for the first time in a 3D compressible wing boundary-layer based on a linearized-DNS time-stepper approach. The present findings are compared to previous investigations on this issue, that were almost exclusively carried out with two-dimensional boundary layers.