Japan STA Program: Turbulence Structure and Sediment- Transport Field near a Flow Obstruction at the Bed of a Hydraulically Rough Turbulent Boundary Layer

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Schmeeckle 9803854 This award supports a 24 month Science and Technology Agency of Japan (STA) Postdoctoral Fellowship for Dr. Mark Schmeeckle at the Civil Engineering Research Institute (CERI) in Sapporo, Japan. Dr. Schmeeckle will work with Dr. Hitoshi Baba, General Director, CERI, on a research project entitled "Turbulence Structure and Sediment-transport Field Near a Flow Obstruction at the Bed of a Hydraulically Rough Turbulent Boundary Layer." The scour of sediment from around river structures during flood is a major engineering concern. Such scour can lead to the loss of the structure or expensive repairs. Unfortunately, the prediction of scour is often based on empirical methods with little physical understanding, and even scale models are difficult because it is nearly impossible to accurately scale both the flow and sediment transport fields simultaneously. Previous physically based sediment transport models only considered mean flow conditions in simplified turbulence fields and performed poorly in complex flow conditions such as around river structures. In this study a newly developed model, which directly couples the instantaneous near-bed velocity to the sediment transport field, will be applied to the case of flow around a cylindrical pier. To accomplish this goal, high-frequency measurements of near-bed velocities around the pier will be collected. These velocity measurements will then be used to drive the sediment transport model, and the sediment transport will in turn be used to predict the evolution of the scour profile around the cylinder. Successful completion of this project will result in a physically based understanding of scour around river structures. ***