Motion Responses of a Berthed Tank under Resonance Coupling Effect of Internal Sloshing and Gap Flow

Tengxiao Wang,Yi Liu,Heng Jin,Mengfan Lou,Xinyu Wang

doi:10.3390/w13243625

Tengxiao Wang, Yi Liu + Show 3 more

Open Access

https://doi.org/10.3390/w13243625

Copy DOI

Abstract

The growth of global energy transportation has promoted the rapid increase of large-scale LNG (liquefied natural gas) carriers, and concerns around the safety of LNG ships has attracted significant attention. Such a floating structure is affected by the external wave excitation and internal liquid sloshing. The interaction between the structure’s motion and the internal sloshing under wave actions may lead to the ship experiencing an unexpected accident. In this research, a hydrodynamic experiment is conducted to investigate the motion responses of a floating tank mooring, both close to and away from a dock. The resonance coupling effect of the internal sloshing and gap flow on the tank’s motion is considered. Based on the measured motion trajectory of the floating tank, the stability and safety of the floating tank are estimated. The results show that the sloshing resonance and narrow gap resonance are beneficial to the stability of the ship. This is helpful for controlling the motion of a berthed ship under wave action with a reasonable selection of the gap distance and the liquid level.

Highlights

The surge motion was insensitive with variations in the liquid sloshing status
The coupled effect of sloshing and narrow gap resonance on the motion response of the liquid tank was investigated based on the experimental test in this research
The water level of the floating tank and narrow gap width was adjusted as variables and the motion response of the floating tank was analyzed

Summary

Introduction

Understanding the motion responses of the liquid cargo ship under the combined actions of multiple loads may be necessary for ship design. In the past twenty years, the coupling effect between sloshing and ship motion has attracted the attention of many researchers. The coupling actions of the liquid motion in the ship tank and the external wave loads may cause instability of the ship. A time-domain simulation method with nonlinear viscous sloshing calculation was adopted by Lee et al [3] and they found that the most pronounced coupling effects are the shift or split of peak-motion frequencies. Jiang and Bai [9] numerically investigated the coupling effect of a swaying box and its internal

Objectives

Methods

Results

Conclusion