Unsteady drag force measurements over bodies with various configurations in a vertical shock tube

Abstract

Paper reports the result of unsteady drag force measurements and their comparison with numerical simulation. Experiments were conducted in a vertical shock tube consisting of a 300 mm i.d. and 2.5 m long high-pressure chamber and a 300 mm × 300 mm square low-pressure channel of 5 m in length. Models with various configurations installed with accelerometers in them were suspended along the low-pressure test section and then planar shock waves at shock Mach number of 1.22 in air were loaded on these models. Model shapes were cones with smooth and coarse surface finish, a double cone a sphere, a 2:3 ellipsoid and a cylinder. The time variation of drag forces exerted on the models was compared to that obtained by solving numerically the Euler equations. A good agreement was obtained between the experiments and numerical results. Unsteady drag force over these models shows peak value and gradually decreases to its steady value.