Release Time:2019-03-12  Hits:

Indexed by: Conference Paper

Date of Publication: 2007-01-01

Included Journals: CPCI-S

Page Number: 320-323

Key Words: groupiness; groupiness factor; wave-current interaction; wavelet transform; local wavelet energy density

Abstract: Groupiness variations of irregular waves propagating over a submerged sill and the effects of depth-uniform currents on it are studied by detailed laboratory measurements. Groupiness factor (GF) based on the local wavelet energy density is used in this research to describe the groupiness degree of waves and the stability of the GF is also discussed. The results show that the breaking event can alter waves: groupiness essentially. For all tested cases, before wave breaking or blocking event happens, GF does not vary significantly. After wave breaking, however, the groupiness decreases rapidly. The groupiness on the condition of the following current is higher than that without current present during the whole propagation process. And under the opposing current condition, the groupiness is higher than that in the pure wave condition before wave breaks, and decreases more rapidly than that under pure wave conditions after wave breaking.