Observations of Velocities and Orientations of Cylindrical Bodies at Terminal Condition in Water

摘要

Trajectories of 1/3rd-scale and full-scale cylindrical bottom mine models falling in the water column are found to be much more complex than predicted by a present impact burial prediction model. For cylinders released in air, air bubbles trapped when the cylinder enters the water appear to dampen turbulent boundary effects resulting in stable trajectories while the bubbles remain attached. With loss of trapped air bubbles during descent through the water, turbulent wake and boundary layer effects generate a wide range of motion and lateral excursion. This paper offers some preliminary projections for the extent of cylinder excursion and for orientations and velocities to be expected at the bottom.