AXISYMMETRICAL TRANSLATION OF A SLENDER TORUS ALONG A CIRCULAR TUBE

The symmetrical sedimentation of a slender solid torus in a quiescent fluid contained in an infinitely long vertical circular cylinder (so t hat the torus's symmetry axis lies along the cylinder axis) is examine d theoretically by making an expansion in terms of a slenderness ratio ic. The results for the drag force on the torus, obtained up to terms of order kappa(2), are compared with the results obtained from the th eories of Johnson and Wu (1979) and of O' Neill (1984) and also with t he experimental results obtained by Amakaroon et al. (1982).