LAUSR

In this paper, the research of mean and slowly varying wave drift forces on a moored semi-submersible platform in irregular moderate waves are carried out. Both experimental and numerical studies are included. Experimental tests with a semi-submersible platform model scaled at 1:70 in an ocean basin were performed with focus on wave drift forces at low frequencies. Both head sea and beam sea conditions were tested. The measured results are compared with numerical simulation using the diffraction analysis program based on three-dimensional potential theory in time domain. Both head sea and beam sea tests are considered. It is found that the experimental and numerical results agree well with each other in the smaller waves for both head and beam sea tests, but not so well in the higher wave for head sea test.