NUMERICAL CALCULATION OF FLOWS BY A RUBBLE MOUND GROIN BY A COMBINED MODEL OF A POROUS FLOW MODEL WITH A NONDARCIAN RESISTANCE LAW AND A 3-DIMENSIONAL LES MODEL

Abstract

This study present a combined numerical model of a porous flow model that employ a non-Darcian resistance law and a 3-dimensional Large Eddy Simulation model in order to investigate 3-dimensional and temporal structures of flows around a rubble mound groin. A model's accuracy is cross-checked by comparing numerical results to observed results of an existing experiment, and model's results show good agreement in terms of time- and depth-averaged sense. Calculation results also imply that a permeable groin restricts growth of secondary flows in a constriction section. However, a combined model is not able to produce unsteady characteristics of flows that are caused by small scale and structured turbulences in a down-stream region of a groin.