Abstract
Three-dimensional oscillatory phenomena of a radial underexpanded jet are discussed in this paper. The jet issues from a small slit between two circular tubes. Flow field is visualized by the shadowgraph method and numerically simulated using TVD scheme. These are compared well to each other. Typical cell structure of the underexpanded jet is found to be formed around the tube and the shock waves in the cells are shown to be of ring shape. The numerical simulation shows that the flow in the downstream region of cells oscillates almost periodically and density contour lines in such region are seen to be swirled, which is caused by the phase difference in the circumferential direction of the radial jet.
