Local shear and mass transfer on individual coral colonies: Computations in unidirectional and wave-driven flows

Flows through single coral colonies were simulated with an implementation of the Immersed Boundary (IB) method in Large-Eddy Simulation (LES). The method was first validated with magnetic velocimetry experiments, which demonstrated that computational results were within approximately 7% of flow measurements. The algorithm was then applied to simulate unidirectional and wave-driven flow conditions through two morphologically distinct coral colonies that naturally grow in very different hydrodynamic environments, with detailed analysis on spatial hydrodynamic and mass transfer variability. When the hydrodynamics of each coral's native environment was simulated, the dynamics in the interior of both branching species appeared to converge, in spite of vast differences between the hydrodynamic conditions and morphologies. A correlation between local surface shear and mass transfer was derived from simulated data. The results suggest that the corals grew in such a way that mass transfer characteristics are similar despite of vast differences in their physical shapes and hydrodynamic conditions. Key Points When native hydrodynamics is simulated, interior dynamics of the corals converge A correlation between local surface shear and mass transfer was derived LES simulation of flow around coral validated with MRV