LES of turbulent flow over a single coral colony

Turbulent dynamics play an important role in nutrient and mass transfer in corals communities. At the colony scale, transport depends on the formation of the boundary layer at the branch-water interface. To understand the effects of the turbulent dynamics over an individual coral colony, three-dimensional simulations were performed by implementing the immersed boundary method in the large eddy simulation framework for Reynolds numbers between 5,000 and 20,000 for Pocillopora meandrina. We performed detailed calculations of the logarithmic mean velocity profile over the coral surface and quantified the vertical mixing and momentum transport by estimating the Reynold stresses above the top surface of the coral. Additionally, the turbulent kinetic energy budget for the flow was estimated in order to understand the balance of turbulence production and dissipation over the top surface of the colony. The calculation and estimation of these turbulence parameters for a single coral colony furthers our understanding of mass and energy transfer mechanisms in corals. This may help in designing more effective interventions for current challenges faced by corals, like ocean warming and bleaching events.