Wave impacts on a solid deck in transient wave groups

Hongchao Wang, H. Santo, P.H. Taylor, S.S. Dai, A.H. Day, E.S. Chan

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

Wave impacts on an elevated solid deck due to transient focused wave groups are studied numerically. Previously reported experiments with and without an I-beam grillage beneath the deck by Santo et al. (2020) are reproduced successfully in a three-dimensional numerical wave tank based on a two-phase Navier–Stokes solver. The impact loads on the solid deck are relatively simple. The three-dimensional horizontal force, characterised by a single peak in time, is close to two-dimensional, whereas the vertical force consists of upward force and downward suction force. The downward suction force is related to triangularisation of the wetted area underneath the deck and dominated by the added mass effect, which is a three-dimensional effect and therefore any two-dimensional simulation will overpredict the strongly three-dimensional process and the vertical impact loads. The wave impact loads on the solid deck with a grillage are more complicated, with successive force spikes observed for both the horizontal and vertical loads. The significance of entrapped air pockets in the grillage to global wave impact loads is ascertained through interrogating flow field of numerical experiments. It is found that large upward vertical impulsive forces are caused by high local pressures when entrapped down-wave air-pockets are formed, while large downward suction forces are resulted from both high-frequency up-wave air-pocket effect and the low-frequency added mass effect. Large horizontal impulsive forces are due to the combined effects of the down-wave air-pocket and the upward jetting motion of the wave crests. The entrapped air-pocket effects are found to be more important for vertical than horizontal forces.
Original languageEnglish
Article number103755
JournalJournal of Fluids and Structures
Volume114
Early online date23 Sep 2022
DOIs
Publication statusPublished - 31 Oct 2022

Keywords

  • entrapped air
  • extreme wave impact
  • focused wave group
  • I-beam grillage
  • solid deck

Fingerprint

Dive into the research topics of 'Wave impacts on a solid deck in transient wave groups'. Together they form a unique fingerprint.

Cite this