2019 CSDMS meeting-004
An investigation of the impact of Marine Hydrokinetic devices on sediment transport
Marine Hydrokinetic (MHK) technologies provide an opportunity to expand renewable energy by harnessing waves and currents power and converting to electricity for residential and commercial application. Locations with rapid tidal flow, large waves, and large tidal range are being considered for implementation of MHK technologies and extraction of energy. However, little is known about the impact of MHK structures on the surrounding ocean morphology. In this study, the hydrodynamic and morphodynamic numerical model, Delft3d, is used to simulate the erosion and deposition around a bed mounted MHK structure to analyze the impacts of seabed slope, sediment grain size, and wave condition on the long-term stability of the device. We analyzed 10, 15, and 20 degree seabed slopes, and three different sediment grain sizes representing fine, medium, and coarse-grained sand. For wave conditions, we ran storm condition of the frequent 1-2 year recurring storm in North Carolina Coast, which occurred during Hurricane Mathew in 2016. We also tested the mean wave conditions and the extreme 100-year storm for the same location. Our initial results suggest that steeper sloped beds, finer sediment grains, and larger wave heights will be more problematic for increasing total deposition and burial of bed-mounted MHK devices. However, depending on the type of MHK device, this impact may not be as important as potential scour around the MHK leading to toppling and failure of the device. Moreover, for extreme storm conditions (i.e. the 100 year storm), scour and potential collapse of the foundation or anchor of the bed-mounted MHK may be a serious concern.