Computational and Experimental Analysis of Ballast Water Exchange

Abstract

Abstract The objective of the present study is to use experimental and computational fluid dynamics (CFD) methods to examine the flow behavior inside ballast tanks during flow‐through ballast water exchange (BWE), and to investigate the exchange effectiveness. Validation efforts are conducted based on comparisons with data collected in a 1/3‐scale model of a portion of a typical ballast tank for a bulk carrier. Comparisons between the measured data and computational predictions are in good agreement. Numerical simulations are also performed for a typical full‐scale ballast tank in a 35,000 dwt handysize bulk carrier, a ship type that represents a large proportion of the oceangoing vessels that ply the Great Lakes trade routes. The results of this study may help explain the variable results of ballast water exchange experiments documented to date, lead to ballast tank structural modification recommendations to improve overall ballast water exchange effectiveness, minimize deadspots, reduce sediment deposition and accumulation, and provide the insight and knowledge to select and enhance treatment technologies, thus reducing the threat of coastal invasive species being discharged in coastal ecosystems.