An Experiment on the Slow Drift Oscillations of a Moored Floating Body in Irregular Waves

Abstract

An experiment on the slow drift oscillations of a moored box-type floating body in irregular waves is carried out in the Experiment Tank of Osaka University. The natural periods of the swaying motion of its system are changed systematically by changing the spring constant of the mooring lines, and the mean wave periods of irregular waves are also changed. The phenomena of the slow drift are confirmed from the results of spectral analysis of the measured swaying motions. The results of experiments are compared with those of theoretical calculations by Pinkster's method and Zarnick's method, and fairly good agreement is obtained.