Experimental analysis of transition delay by means of roughness elements
2006 (English)In: Collection of Technical Papers: 36th AIAA Fluid Dynamics Conference, 2006, 1464-1478 p.Conference paper (Refereed)
An experimental activity aimed at the development of a passive method for viscous drag reduction in an aerodynamic body is presented. The reduction is achieved by delaying the laminar-turbulent transition of the boundary layer. The research is motivated by previous linear stability analysis where it was demonstrated that stable streaks in a boundary layer are capable to stabilize the growth of Tollmien-Schlichting waves. In this paper the results of a series of experiments on a flat plate are presented. Firstly, it is shown that by means of suitable roughness elements it is possible to generate stable steady streaks of amplitudes up to 12% of the free stream velocity. Secondly, it is demonstrated that the generated streaks are really effective in reducing the growth of the Tollmien-Schlichting waves as predicted by the theory. Finally, it is shown that using this passive control technique it is possible to sensibly delay transition to turbulence.
Place, publisher, year, edition, pages
2006. 1464-1478 p.
Other Engineering and Technologies not elsewhere specified
IdentifiersURN: urn:nbn:se:kth:diva-87567ScopusID: 2-s2.0-33845262031ISBN: 1563478102ISBN: 9781563478109OAI: oai:DiVA.org:kth-87567DiVA: diva2:501756
36th AIAA Fluid Dynamics Confernce; San Francisco, CA; 5 June 2006 through 8 June 2006
QC 201202212012-02-142012-02-142012-02-21Bibliographically approved