title: Simulation and analysis of flow patterns around the scleractinian coral Madracis mirabilis (Duchassaing and Michelotti).
abstract: Three-dimensional morphologies of Madracis mirabilis were obtained using X-ray computed tomography scanning techniques. The morphologies were used to simulate the flow patterns around the colony. In the simulations, the thin-branching low-flow morph with a relatively larger branch-spacing was compared with the more compact high-flow morph of M. mirabilis. For both morphologies, the inside-colony flow velocities were computed for Reynolds numbers ranging from 154 to 3840. In the high-flow morph, it was found that in the range of investigated Reynolds numbers a stagnant region develops within the colony, whereas in the low-flow morph the stagnant region disappeared. Experiments done under natural conditions suggest that a morph is adapted to a certain external flow velocity and develops a stagnant region below a particular threshold for the external flow velocity. When the external flow velocity exceeds a certain threshold, which is characteristic for the growth form, the core velocity becomes equal to the external velocity. A potential application of a profile of core velocities for a range of Reynolds numbers for a certain morph is the prediction of the optimal external flow velocity for a certain morph, and this can be used to assess the state of the physical (palaeo-) environment.
authors.affiliation: Section of Computational Science, Faculty of Science, University of Amsterdam, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands. jaapk@science.uva.nl
authors.forename: Jaap A
authors.initials: JA
authors.lastname: Kaandorp
authors.forename: Evert A
authors.initials: EA
authors.lastname: Koopman
authors.forename: Peter M A
authors.initials: PM
authors.lastname: Sloot
authors.forename: Rolf P M
authors.initials: RP
authors.lastname: Bak
authors.forename: Mark J A
authors.initials: MJ
authors.lastname: Vermeij
authors.forename: Leo E H
authors.initials: LE
authors.lastname: Lampmann
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000033:anatomy & histology* / Q000502:physiology*; D003198:Computer Simulation; D008962:Models, Theoretical; D012212:Rheology; D012623:Seawater; D014057:Tomography, X-Ray Computed