An experimental investigation of 3D subaqueous barchan dunes and their morphodynamic processes

In order to experimentally investigate the flow dynamics around a 3D barchan dune, herein we adopt a new experimental approach that enables us to quantify flow around complex morphologies using a refractive index matching (RIM) flume. This technique allows the model barchan to be rendered invisible, thus permitting use of standard optical techniques for flow-field quantification. Here, we present full details of this unique new RIM facility and detail its use to investigate flow around a model barchan dune. These results are compared to past experimental and numerical models of barchan