Quantitative visualization of the flow around a square-section cylinder at incidence

Abstract

Particle image velocimetry (PIV) has been used to measure the flow around a 2D square-section cylinder at incidence. A detailed statistical flow field characterization was obtained in terms of the spatial distributions of the mean velocity and turbulence components. The observed change of the mean flow pattern with incidence agrees with earlier studies and is consistent with previously reported behavior of the normal force component. At small angles of attack a downward force results, as a consequence of the increased curvature of the lower shear layer. At higher incidence, this trend is reversed due to reattachment of the separated shear layer on the afterbody. Furthermore, experimental force data are provided that were obtained from PIV velocity field data through application of a control-volume approach.