The Second Order Contribution to Wave Crest Amplitude — Random Simulations and NewWave

摘要

Estimating the probability of a wave crest exceeding a given thresholdis of fundamental importance in offshore engineering. At presentsecond-order theory is used, with the Forristall distribution typicallybeing used for this calculation. In this paper we investigate severalpoints in connection with this approach. Firstly we examine some of thesensitivities involved in deriving second order statistics, including thehigh frequency cut-off, the directional spreading and spectralbandwidth. The paper then examines how the second order contributionvaries for waves of different shapes. We investigate whether theNewWave can be used to predict the second order contribution to awave-crest but find that the variation in wave shape is too great for thisto be practical.