Relative wave motion and shipping water on deck of Mega-float structure

Abstract

This paper presents experimental results on the relative wave motion characteristics and shipping water phenomena of VLFS in waves. Three models having different values of elasticity were used to measure the relative wave motion and level of shipped water on deck at the weather side end of the models. The experiments were performed both in regular and irregular waves. The response amplitude operator of the relative wave motion was obtained and compared with theoretical calculation. Good agreement is shown between both results as far as the linear component is concerned. The probability of occurrence of shipping water and the probability distribution of relative wave motion were investigated by irregular wave experiments. It was found that the relative wave motion includes some kind of non-linear features. Comparing the results of three models, it becomes clear that the non-linearity of relative wave motion is largely influenced by non-linearity of model's elasticity. As to shipping water phenomena of VLFS, the so-called dam collapse model was found applicable in predicting the volume of shipped water on deck by use of an empirical coefficient determined experimentally.