Experimental Study by Visualization of the Behavioral Properties of the Vortex Structures and the Ecltements on the Upper Surface of a Revolution Warhead

Abstract

Abderrahmane ABENE

Scientific research of the flow visualizations, developed on the upper surface of the cones and warhead of revolution, the delta or Gothic wings and that of the warheads of the revolution, were performed in the wind tunnel of the aerodynamics and hydrodynamics laboratory of the Polytechnic University of Haut de France. This research has made it possible to better analyze and understand the phenomena of vortex structures and vortex spalling see photos2,3,4,5 and 6. angles, thus defined, over a wide range of Reynolds. The study concerns visualization analysis of the behavioral properties at the top surface of a revolution ogive having an apex angle of 74.5 ° at low angle of attack and performed at variable speeds. It has been noted that speed variations have no influence on the behavioral properties of the development of vortex structures whereas, on the other hand, changes in angles of incidence strongly influence this development. The study of the rise of the vortex rupture at the angles of attack has revealed original behavioral properties which find their expression notably in the discontinuous evolution, in terms of angle at the summit, of the angles of attack which define the beginning and end of the ascent of this vortex failure. These properties probably reflect those already observed in similar studies carried out on the delta and Gothic wings and on the cones. However, no current theory seems to be able to provide a direct explanation of these phenomena of the splitting of the whirling structures.

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