Volume 9, 2017Progress in Flight Physics
|Page(s)||497 - 516|
|Section||Stability, transition, and turbulence|
|Published online||20 June 2017|
Free transition on a slender cone in a quiet and a conventional wind tunnel and the effect of ultrasonically absorptive materials
German Aerospace Center (DLR) Supersonic and Hypersonic Technology Department Institute of Aerodynamics and Flow Technology Linder Höhe, Köln 51147, Germany
2 School of Aeronautics and Astronautics Purdue University West Lafayette, IN 47907-1282, USA
Transition from laminar to turbulent hypersonic boundary layers is the topic of several research projects world-wide. Most experimental work is done in conventional wind tunnels, although their free stream turbulence does not match free flight conditions and has a significant in§uence onto the transition process. Experiments performed with the same 3 degree half angle cone in a conventional and a quiet wind tunnel at Mach 6 justify this approach. The formation, amplification, and decay of the second (Mack) modes is compared based on high-frequency pressure measurements. In addition, damping of these modes with ultrasonically absorptive surfaces was tested.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.