TY - JOUR
T1 - Flow analysis of vortex generators on wing sections by stereoscopic particle image velocimetry measurements
AU - Velte, Clara Marika
AU - Hansen, Martin Otto Laver
AU - Cavar, Dalibor
N1 - Invited paper
PY - 2008
Y1 - 2008
N2 - Stereoscopic particle image velocimetry measurements have been executed in a low speed wind tunnel in spanwise planes in the flow past a row of vortex generators, mounted on a bump in a fashion producing counter-rotating vortices. The measurement technique is a powerful tool which provides all three velocity components in the entire measurement plane. The objective of this study is to investigate the effect of vortex generators in a turbulent, separating, low Reynolds number (Re = 20 000) boundary layer over a geometry which is generating an adverse pressure gradient similar to the flow past a wind turbine blade. The low Reynolds number is chosen on the basis that this is a fundamental investigation of the structures of the flow induced by vortex generators and the fact that one obtains a thicker boundary layer and larger structures evoked by the actuating devices, which are easier to measure and resolve. The flow behaves as expected, in the sense that the vortices transport high momentum fluid into the boundary layer, making it thinner and more resistant to the adverse pressure gradient with respect to separation. The amount of reversed flow is significantly reduced when vortex generators are applied. The idea behind the experiments is that the results will be offered for validation of modeling of the effect of vortex generators using various numerical codes. Initial large eddy simulation (LES) computations have been performed that show the same qualitative
behaviour as in the experiments.
AB - Stereoscopic particle image velocimetry measurements have been executed in a low speed wind tunnel in spanwise planes in the flow past a row of vortex generators, mounted on a bump in a fashion producing counter-rotating vortices. The measurement technique is a powerful tool which provides all three velocity components in the entire measurement plane. The objective of this study is to investigate the effect of vortex generators in a turbulent, separating, low Reynolds number (Re = 20 000) boundary layer over a geometry which is generating an adverse pressure gradient similar to the flow past a wind turbine blade. The low Reynolds number is chosen on the basis that this is a fundamental investigation of the structures of the flow induced by vortex generators and the fact that one obtains a thicker boundary layer and larger structures evoked by the actuating devices, which are easier to measure and resolve. The flow behaves as expected, in the sense that the vortices transport high momentum fluid into the boundary layer, making it thinner and more resistant to the adverse pressure gradient with respect to separation. The amount of reversed flow is significantly reduced when vortex generators are applied. The idea behind the experiments is that the results will be offered for validation of modeling of the effect of vortex generators using various numerical codes. Initial large eddy simulation (LES) computations have been performed that show the same qualitative
behaviour as in the experiments.
U2 - 10.1088/1748-9326/3/1/015006
DO - 10.1088/1748-9326/3/1/015006
M3 - Journal article
SN - 1748-9326
VL - 3
SP - 1
EP - 11
JO - Environmental Research Letters
JF - Environmental Research Letters
IS - 1
ER -