FREE-SURFACE FLOW DUE TO IMPULSIVE MOTION OF A SUBMERGED CIRCULAR-CYLINDER

The impulsively starting motion of a circular cylinder submerged horiz ontally below a free surface is studied analytically using a small-tim e expansion. The series expansion is taken as far as necessary to incl ude the leading gravitational effects for two cases: constant velocity and constant acceleration, both commencing from rest. The hydrodynami c force on the cylinder and the surface elevation are calculated and e xpressed in terms of bipolar coordinates. Comparisons are also made wi th earlier theoretical and experimental work. The theory is valid for arbitrary value of submergence depth to cylinder radius.