Numerical prediction of the effects of oceanic flow characters on the evolution of CO₂ enriched plumes

The near-field dynamics of CO₂ rich plume draw attention of assessment of the local impacts of CO₂ ocean sequestration on natural oceanic environment. In this study, we attempt to predict numerically the role of ocean flow characters, including the current profile and the turbulent intensify, and of the injection parameters, including the injection rate and initial droplet diameters, on the evolution of liquid CO₂ (LCO ₂) droplet and CO₂ enriched seawater plumes. The numerical model we used in this study is a two-phase large-eddy simulation model. From numerical experiments we found: 1). The plume height (both LCO₂ plume and CO₂ enriched seawater plume) is insensitive to ocean currents and turbulent intensify but do sensitive to initial droplet diameter. For releasing rates of 0.6kg/sec, the estimated plume heights at initial droplet diameters of 8.0 and 5.0 millimeter are approximately 170 and 80 meters for different oceanic flows. 2). The physics of CO₂ enriched seawater plume, for instance CO₂ concentration distribution and local largest concentration, however, are governed sensitively by seawater flow characters and alternatively by injection rate and initial droplet diameter. 3). Strong turbulence enhanced the dispersion and mixing of droplets and CO₂ enriched seawater with fresh seawater to produce an improved CO₂ concentration distribution.