HYDRAULICS OF STATIONARY CAPSULE IN PIPE

The variation of pressure along a single cylindrical capsule resting o n the bottom of a pipe is predicted by using the one-dimensional energ y equation, the momentum equation, and the continuity equation with pr oper consideration for the head losses including entrance and exit eff ects, as well as by using experimental values of the energy correction factor alpha and the momentum correction factor beta of the eccentric annular flow around the capsule. The theory is compared with previous ly published experimental data and they agree reasonably well. The the ory is extended to predict the drag on a single stationary capsule res ting on pipe floor, the pressure coefficient of the capsule end, and t he incipient velocity. Comparison with experimental data from several sources shows the superiority of the new theory to the existing theory , which ignores entrance and exit effects and assumes concentric capsu les. The new theory can also be used to predict the behavior of a caps ule train provided that the roughness created by the ends of individua l capsules is properly estimated.