ENVIRONMENT AND ENERGY

The gas transfer process across the air-water interface plays an important role in many industrial and environmental systems. Applications in environmental systems include, for instance, the oxygen absorption from the atmosphere into natural water bodies, which is an essential mechanism to overcome deficits of dissolved oxygen. Like many other environmentally important gases oxygen has low diffusivity in water. The interfacial mass transfer of such low-diffusive substances is marked by very thin diffusive layers such as the concentration boundary layer at the interface. The most challenging part in understanding the physical processes lies in resolving the gas transfer in these thin layers. To achieve this, a group of scientists from the Karlsruhe Institute of Technology (KIT) performs direct numerical simulations using a special numerical scheme for the discretization of scalar convection that is capable of resolving the thin diffusive layers on a relatively coarse mesh while avoiding spurious oscillations of the scalar quantity.