Turbulent convection driven by evaporation in water pools

Turbulent natural convection in open cavities is encountered in numerous industrial applications and natural phenomena. In this presentation we report on direct numerical simulations of the problem in hand at different Rayleigh numbers. A shear-free boundary on top of a cubic domain approximates a free surface. At the same location we estimate realistic evaporative and convective heat losses, forming the basis of a non-zero Neumann boundary condition for the temperature. Our simulations predict that the shear-free surface increases heat transfer within the domain, however the exponent in the power-law relation between the Nusselt and Rayleigh numbers, is similar to that of classical turbulent Rayleigh-B\'{e}nard Convection. The effects of the shear-free surface on the large-scale circulation, the thermal boundary layers and the flow statistics are also analyzed herein. Overall, this configuration of turbulent convection shows unique characteristics, borrowing from both turbulent Rayleigh-B\'{e}nard convection and evaporative cooling.