Water Tunnel Experiments on Spheres in Cavity Flow

Abstract

A program of experimental work on air-supported cavity flow has been in progress in the Free Surface Tunnel for some time now and a considerable amount of data has been taken. Most of this work has been concerned with cones and disks, which have distinct points at which the cavity separates from the nose, but it was thought worthwhile to extend the investigations to include continuously curving noses with shapes such as spheres and ellipsoids. As a start in this direction, a number of tests have been made on spheres with attached cavities. The sphere was selected as a convenient shape because of its simplicity, the availability of models already made up, and the possibility of comparing results with those of other investigators. The purpose of the present note is to report the test data taken so far; detailed analysis and comparison will be postponed for a future report.