Session: 12-02-02 Wave-Structure Interactions II

Paper Number: 131022

131022 - Preliminary Investigation on the Effects of Gusty Wind Forcing on Steep Unidirectional Waves 

In air-sea interaction, wind, the driving force that generates surface waves, exchanges energy and momentum with waves. However, the airflow above the waves leads to the evolution of nonlinear waves being more complex. Therefore, it is crucial to investigate the role of wind-wave interaction in wave evolution and consequent extreme wave generation. To address this issue, the parametric laboratory experiments were carried out at 300-meter-long wave tank at shanghai jiaotonh university to investigate the effect of wind-wave interaction on nonlinear wave evolution over the long distance. In this paper, we shall present some preliminary results with three sets of random waves generated from the JONSWAP spectrum with different Benjamin-Feir index (BFI). While the wave is generated by wave paddle, the wind is generated by a fan array in the large-scale open wave tank. We investigate the long-time nonlinear wave evolution with gusty wind and discuss the statistical properties of waves. We find that the gusty wind forcing enhances the 'heavy tail' effect in the exceedance probability of wave height, and the kurtosis of the wave elevation experiences a noticeable increase with the wind forcing. It suggests that the gusty wind forcing leads the nonlinear waves to deviate from equilibrium, increasing the probability of extreme events.

Presenting Author: Ye Li Shanghai Jiaotong University

Presenting Author Biography: Dr. Ye Li is a professor at Shanghai Jiaotong University, and director of China-Australia Joint Research Center for offshore wind and wave. Prior to that, he was a senior scientist at US National Renewable Energy Lab. Dr.Li is a fellow of ASME.

Authors:

Zitan Zhang Shanghai Jiaotong University
Ye Li Shanghai Jiaotong University