Overcoming the added mass effect in FSI calculations relating to dynamic squat. (1st January 2023)

• Record Type: Journal Article
• Authors: Lefrançois, Emmanuel; Yang, Bo; Kaidi, Sami; Mohamad, Nisrine
• Is Part Of: Ocean engineering. Volume 267(2023)
• Publication Date: 2023-01-01
• Subjects: Ship squat effect -- Dynamics -- Fluid–structure interaction -- Added mass -- Weak coupling -- Energy conservation; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2022.113280
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: This paper presents a corrected partitioned scheme for investigating fluid–structure interaction (FSI) generated by ship squat in presence of transient effects. A theoretical example describing the motion of a piston enclosed in a U-tube gives rise to an analysis of the divergence effect resulting from added mass, and it has been concluded that divergence always occurs when the mass in motion is less than the added mass. An added-mass-corrected scheme is proposed to guarantee the convergence of the coupling scheme irrespective of the mass ratio. This corrected scheme is successfully applied to the ship dynamics in an analysis of ship squat via a non-stationary potential fluid flow approach. The results of our coupled calculations have been compared to the squat stability models detailed in Alderf et al. (2010); Alderf et al. (2015) in which transient effects were neglected in the fluid flow solver. Finally, energy transfers between the ship's motion and the fluid flow have been analyzed. We confirm the energy conservation capability of the proposed fluid–structure coupling scheme in relation to the transient response of the ship. Highlights: A FSI model is exposed to study added mass effect resulting from transient effects. For a level of added mass effect, classical partitioned coupling schemes diverge. The corrected version integrating added mass effect systematically converges. Added mass is obtained from a post-processing step of the potential approach method. The corrected scheme makes affordable the severe transient ship squat effect.