LES study of CO2 enriched gravity currents

Earlier integrated gravity current models have been used to study both natural existing ocean currents and artificially generated currents with CO2 enriched seawater. The latter being a possible option for ocean disposal of waste CO2 from powerplants or other large point sources. These types of models are not resolving the interior of the current but only describes the mean velocity and density over cross-sections. The models parameterise friction and entrainment, and earlier studies have shown a high sensitivity on the friction parameterisation and thereby the entrainment of ambient water. In this study a Navier Stokes solver connected with a Large Eddy Simulation (LES), to account for the cascade of energy to subgrid scale eddies, is used to model the current close to the outlet. The code resolves the interior of the current and no entrainment or friction parameterisations are needed. Only the first 250 meters after the outlet are modelled and the results shows high entrainment. The numerical results are used together with a simple time dependent integrated gravity current model to estimate entrainment and friction parameters. (C) 1997 Elsevier Science Ltd.