Spatial correlations of fluctuating lift forces on rectangular sections with unsteady reattaching flow in smooth flow

Abstract

Spatial correlations of fluctuating lift forces on 2-dimensional rectangular sections with various side ratios in smooth flow are evaluated by wind tunnel tests and LES analyses. The effect of unsteady reattachment of separating shear layer on spatial correlations is investigated in this research. The results of wind tunnel tests reveal that the unsteady reattachment strengthens the spatial correlation. The difference of shear layer movement between completely separating flow type and unsteady reattaching flow type is clarified by LES analyses. The shear forces between two separating shear layers caused by phase difference of Karman vortex in reattaching flow leads to high correlation.