Where fH is the horizontal wave forces acting on certain height of cylinder, D f is the horizontal drag force, I f is the horizontal inertial force, D C is the drag coefficient, 0 V is the volume of displacement of unit height, A is projection area
of unit height vertical to the wave motion direction, x u is the velocity in horizontal direction of wave particle, m C is the
added mass coefficient, M C is the mass coefficient, and D is the diameter of the cylinder.