Effect of Cutout at Edges to Drag Reduction of Square Prism with Angle of Attack.

Abstract

The purpose of the present paper is to examine experimentally the drag reduction of square prisms with the cutout of rectangular shape at their edges. The drag and lift coefficients, the base-pressure, the Strouhal number and pressure distribution are measured for various angles of attack from 0° to 90°. The present experiment shows: (1) The drag coefficient of the square prism with a cutout is smaller than that without the cutout. (2) For the case of angle of attack small, the drag coefficient of the square prism with the cutout is approximately constant against the change of the angle of attack and it is smaller than that of a circular cylinder. (3) The minimum pressure coefficient on the front cut surfaces is smaller than base pressure coefficient, in the case where the drag coefficient becomes minimum value, 0.8.