Flow in Two-Dimensional Rectangular Cavities.

Abstract

In this paper we describe the flow associated with two-dimensional surface-mounted rectangular cavities. The experiment was carried out in two types wind tunnel and water channel. A significant aspect of the study has been an examination of the effects of changing the ratio of width/depth in the sectional geometries of two-dimensional cavities from 1 to ∞ to be backward facing step. The time mean surface pressure distributions, mean velocity, fluctuating velocities, and Reynolds stresses inside cavities were measured as the ratio of width/depth was varied. The flow pattern inside cavities was observed by flow-visualization. Consequently it was found that (i) the transition from the open cavities to the closed cavities occurs at W/D=8.8∼9 in wind tunnel experiment, (ii) this is reflected in the mixing phenomenon associated with an increase in cavity drag, and (iii) the similarity is established in the velocity profiles of the shear layer around the cavity flow and the reverse flow in the recirculation region.