Time Mean Drifting Forces on a Cylinder in Water of Finite Depths -Direct Pressure Integration Method-

유한(有限)깊이의 물에 떠있는 주상체(柱狀體)에 작용(作用)하는 시간평균표류력(時間平均漂流力) -직접압력(直接壓力) 적분법(積分法)-

In this paper, the second order time mean forces acting on the circular cylinder floating on the free surface of a finite water depth are calculated. Under the assumption that fluid is idea and the wave the linear gravity wave, the velocity potential is calculated by the source distribution method, and the second order time mean lateral and vertical drifting forces are calculated by the direct integration of fluid pressures over the immersed body surface. The comparison of the lateral drifting forces with Rhee's results by momentum theorem shows good agreements. And it is shown that the second order time sinkage forces of a floating circular cylinder cross zero for all water depths.