Inline Forces on Fixed Vertical Cylinder in Waves

A wave-tank test is performed in which the forces on fixed vertical tubes of two sizes are measured. In addition to the total forces, the forces on two 1-ft (0.3-m) submerged sections of the tubes are measured in each test of the individual tubes. The hydrodynamic coefficients associated with the 1-ft (0.3-m) sections are computed from these measured inline forces with the help of the Morison equation. The stream function theory is employed to define the water-particle kinematices. The coefficients are found to be functions of the Keulegan-Carpenter number. The total forces on the tubes computed from the mean values of the hydrodynamic coefficients correlate well with the corresponding measured total forces. The coefficients are shown to be not so different in values from those obtained in a two-dimensional flow test.