Numerical Performance Characteristic of Embedded Convex Rigid-ring Baffle in Long Moving Vessels

Abstract

Slosh-induced instability arising from oscillations of their fluid content often occur in Long Moving Vessels (LMV). Flat Rigid-ring Baffle (FRB) often used as a slosh-suppression device, Abramson, H. N. (1966) in LMV but due to unappreciable performance of this suppression device hence, quest to research into other baffle configurations is a necessity. In this work, investigation of sloshing characteristics numerically of LMV equipped with two types of Rigid-ring baffles of varying geometries namely: Convex Rigid-ring Baffle-1, 0.04m pitch (CVRB1) and Convex Rigid-ring Baffle-2, 0.04m pitch (CVRB2).and Flat Rigid-ring Baffle (FRB) as baseline at gravity (g = 9.81 m/s2), Hastings et al. (1965). Continuity and Navier-Stokes Equations were used as model governing equations which were developed and solved using Finite Element Analysis technique, Mohan, A. (2014) to obtain pressure and velocity which were used to evaluate forces at the cylinder’s wall. These parameters were used to evaluate Damping Ratio (DR) of each baffle at (72, 66 and 59) % standard positions, in a 75% Water-filled Cylinder (WCC) having slenderness ratio of 1.5 excited at frequency of 2 Hz. Data were analysed using descriptive statistics and ANOVA at α 0.05  (Hatch, M. R. 2001). The results showed that, Convex baffles exhibited better damping characteristics than other baffles geometries with highest DRs at (72 and 59) % water-filled positions of the cylinder. Also, the shape of the baffle enhances the reduction of hydrodynamic pounding on the tank’s wall consequently lessens the negative effect of fluid-structure interaction.