Study on vessel–pipe coupling dynamic behavior under regular waves in deep sea mining process

Abstract

A indirect time-domain coupling dynamic mathematical model of mining vessel–lifting pipe was established by combining the analysis method of mining vessel and lifting pipe in this paper. The vessel–pipe coupling experiments under various wave conditions were performed at the China National Ocean Technology Center, and a dynamic computer simulation of the coupled model was conducted to verify the effectiveness of the experiment and simulation. To simulate the coupling dynamic behavior, we established the hydrodynamic model of the vessel using AQWA software to determine the response amplitude operators (RAOs). Subsequently, the obtained RAO matrix was merged into an OrcaFlex model to analyze the dynamics of the mining vessel–lifting pipe interaction. In addition, the influencing factors of vessel–pipe coupling dynamics were estimated quantitatively, including regular wave, buffer mass, and sailing velocity. The findings show that the coupling effect has a significant impact on the vessel–pipe dynamic behavior, which has a strong relevance with surface waves, but a weak relevance with sailing velocity. In the process of changing the wave direction from 180° to 90°, the tension at the top of the pipeline increases by 19.31% and the coupling time decreases by 66.67%.