Simulation of the Periodically Perturbed Separated and Reattaching Flow over a Backward-Facing Step
Author/Authors :
Mehrez، Z. نويسنده , , . Bouterra، M نويسنده , , El Cafsi، A. نويسنده , , Belghith، A. نويسنده , , Le Quéré، P. نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی 6 سال 2010
Pages :
8
From page :
1
To page :
8
Abstract :
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In this work, the Large Eddy Simulation (LES) methodology is used to study the effects of a periodic perturbation
introduced into a separated shear layer behind a backward-facing step. This study carried out by acting on the two
parameters characteristics of the perturbation: frequency and amplitude. The obtained results reveal the existence of
an optimum perturbation frequency value, St p = 0.25, in terms of the reduced reattachment length. At this perturbation
frequency value, we observed an increase in the vortical shedding frequency in the reattachment zone with a
significant change of the structure of the flow. The value of the optimum frequency appears to be independent of the
perturbation amplitude. At this frequency the maximum decrease of reattachment length is 50% and the maximum
increase of vortical shedding frequency is 43 % compared to the unperturbed case.
