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Experiments on the aerodynamic behaviour of square cylinders with rounded corners at Reynolds numbers up to 12 million

van Hinsberg, Nils and Schewe, Günter and Jacobs, Markus (2017) Experiments on the aerodynamic behaviour of square cylinders with rounded corners at Reynolds numbers up to 12 million. Journal of Fluids and Structures (74C), pp. 214-233. Elsevier. DOI: 10.1016/j.jfluidstructs.2017.08.002 ISSN 0889-9746

Full text not available from this repository.

Official URL: http://www.sciencedirect.com/science/article/pii/S0889974616307356

Abstract

The influence of the angle of incidence and corner radius on the aerodynamics of square-section cylinders is studied by means of wind tunnel experiments. Two different corner radii (r∕D=0.16 and 0.29) were investigated at three angles of incidence (alpha=0deg, −22.5deg and −45deg). Steady and unsteady global forces and local surface pressures were measured in the high-pressure wind tunnel in Göttingen. The Reynolds number was varied up to values as high as 12x10^6, thereby spanning the known flow state regimes up to high transcritical. The results demonstrated that a decrease of the cylinder’s bluffness induced lower maximum drag coefficients and r.m.s. values, as well as higher Strouhal numbers in all flow state regimes. Furthermore, the critical Reynolds numbers shifted to significantly lower values. For the cylinder configurations at alpha=0deg no upper transition or transcritical flow state was present up to ReD=12 million. A decrease in the angle of incidence resulted in a significant reduction of the length of the supercritical flow state, a shift of the drag force, Strouhal number and base pressure to higher values and an increase of the critical Reynolds numbers. The cylinders at non-zero angles of incidence all displayed a clear critical flow state, at which two discontinuous transitions were observed, accompanied by jumps in the CD and CL values and the Strouhal number. Only three out of six studied configurations experienced hysteresis, where for the high corner radius configuration at alpha=0deg a particularly broad hysteresis effect was measured.

Item URL in elib:https://elib.dlr.de/113866/
Document Type:Article
Title:Experiments on the aerodynamic behaviour of square cylinders with rounded corners at Reynolds numbers up to 12 million
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
van Hinsberg, NilsNils.vanHinsberg (at) dlr.deUNSPECIFIED
Schewe, Günterguenter.schewe (at) dlr.deUNSPECIFIED
Jacobs, Markusmarkus.jacobs (at) dnw.aeroUNSPECIFIED
Date:October 2017
Journal or Publication Title:Journal of Fluids and Structures
Refereed publication:Yes
Open Access:No
In DOAJ:No
In SCOPUS:Yes
In ISI Web of Science:Yes
DOI :10.1016/j.jfluidstructs.2017.08.002
Page Range:pp. 214-233
Publisher:Elsevier
ISSN:0889-9746
Status:Published
Keywords:Reynolds number, flow separation, rounded corners, square section cylinder, bluff body
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:fixed-wing aircraft
DLR - Research area:Aeronautics
DLR - Program:L AR - Aircraft Research
DLR - Research theme (Project):L - Flight Physics
Location: Göttingen
Institutes and Institutions:Institute of Aeroelasticity > Aerolastic Experiments
German-Dutch Windtunnels
Deposited By: van Hinsberg, Dr. Ir. Nils
Deposited On:01 Sep 2017 15:47
Last Modified:10 Jan 2019 15:48

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