Thesis abstract:

«p»In nearshore regions, natural circulation of water caused by differential in temperature plays an important role in the biological and environmental fields across shore, thus this area of study has attracted considerable research interest. Mixing due to natural convection has a key role in maintaining the quality of water through transport of pollutants, nutrients and dissolved chemicals in reservoirs, lakes and coastal regions. This study will investigate the behaviour of natural convection in a shallow inclined domain exposed to uniform heating by solar radiation at water surface. Based on Beer’s law, the amount of solar radiation absorbed at the water surface decays exponentially with depth, the exponent of which depends on the radiation wavelength and the turbidity of water. Some of this radiation is absorbed by the bottom layer and re-emitted back to the water body as boundary heat flux. The flow domain eventually forms two distinct regions; a conductive region nearshore which becomes isothermal and stationary, and a convective region offshore that has a flow velocity associated with large-scale circulation. In order to investigate the problem; a semi-analytical approach along with scaling analysis will be coupled with exact solutions of the Navier-Stokes equations obtained using Direct Numerical Simulations (DNS).«/p»