Effect of spires on boundary layer growth

Abstract

The aim of the present work was to study the boundary layer thickness growth with vertical spires of varying heights and c/c spacing. In this study, it was observed that boundary layer thickness is affected by the presence of vertical spires in wind tunnel. Various spires of different heights 20, 30 and 40 cm with wall clearance of 2.5 cm were used to study their effects. The boundary layer thickness was in turn affected by the configuration of the spires. It was observed that boundary layer thickness increases with increase in height of the spires within the cross section of the wind tunnel and boundary layer thickness. Also, boundary layer thickness increases with decrease in c/c spacing of the spires. At a working section, the velocity profiles were plotted and boundary layer thickness in each case was calculated (the height from the surface to the point of 99 per cent of the main stream velocity). In this way the boundary layer thickness was calculated for different working sections.