Boundary layer modification by means of wall suction and the effect on the wake behind a rectangular forebody
2014 (English)In: Physics of fluids, ISSN 1070-6631, E-ISSN 1089-7666, Vol. 26, no 12, 125105- p.Article in journal (Refereed) Published
The wake characteristics of a two-dimensional rectangular forebody with a smooth leading edge and a blunt trailing edge are investigated. Wall suction is applied along the forebody in order to modify the developing boundary layer. An initially laminar boundary layer subject to suction yields an asymptotic suction boundary layer at the trailing edge of the body, whereas a high enough suction coefficient relaminarizes an initially turbulent boundary layer. The critical suction velocity required to achieve this significant modification of the boundary layer properties is typically in the order of 1% of the free-stream velocity, where the critical suction coefficient depends on the Reynolds number. We show that a thinner boundary layer induces a higher vortex shedding frequency and a lower base pressure. Furthermore, the boundary layer state, laminar or turbulent, has a significant influence on the wake. For example, the Strouhal number based on the effective body thickness is being reduced by 25% from laminar to turbulent inlet conditions.
Place, publisher, year, edition, pages
2014. Vol. 26, no 12, 125105- p.
Circular-Cylinder, Pressure-Gradients, Porous Cylinder, Base-Pressure, Aspect Ratio, Bluff-Body, Flow, Turbulence, Injection, Subject
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-159389DOI: 10.1063/1.4904376ISI: 000347161600046ScopusID: 2-s2.0-84919935697OAI: oai:DiVA.org:kth-159389DiVA: diva2:784645
FunderSwedish Research CouncilEU, European Research Council
QC 201501302015-01-302015-01-292016-03-16Bibliographically approved