Cavity Flow around a Square Cylinder

The characteristics of cavity flow around a square cylinder were experimentally investigated for various angles of attack (α=0°-45°) and cavitation numbers (δυ=0.9-3.9). Measurements of fluid dynamic forces and surface pressure were made and the cavity configuration was recorded with a high-speed video camera. It was clarified that variations of the flow pattern with cavity development depend on the behavior of the separated shear layer. In a perfectly separated flow region (α ≤ 12.5°), fluctuating fluid dynamic forces increase in a specific range of cavitation number. On the other hand, in the reattached region (15°≤ %alpha: ≤45°), the fluctuations reduce monotonically as the cavitation number decreases. At angles of attack α=10° and 12.5° near the reattached flow region, marked increases of the fluctuating forces are caused by the drastic change in the wake structure.