Doctor of Philosophy, The Ohio State University, 2009, Civil Engineering

The present work focuses on the development of a Modular Multi-Component Coastal Ocean Prediction System (mmcops) that incorporates the full 3D wave-current interactions for a better representation of the entrainment and transport mechanics in complex deep and shallow water coastal environments. The system incorporates wind, temperature and atmospheric pressure forcing that drive the circulation, wave, sediment and bottom boundary layer model components. The effects of the wind generated surface waves on the water column and bottom layer dynamics are parametrized by the inclusion of the Stokes drift, and the wave radiation stress terms that quantify the excess of mass and momentum flux produced by the waves. Coupled wave-hydrodynamic models traditionally incorporate the radiation stress terms only into the vertically integrated momentum. Considering the fact that currents are 3D structures, the vertical variation of the radiation stress should be also considered. In the present work the 3D momentum equations are re-derived to include the full 3D impact of the radiation stresses on the currents. As a preliminary test, the system is applied to Lake Michigan with a twofold purpose: a to conduct an initial testing of the model prognostic variables with and without the effect of the waves; and b to develop a methodology required to answer whether the annually observed Spring turbidity nearshore plume in Southern Lake Michigan is transporting material from its origin in one continuous transport mode or as generated by a series of local deposition, resuspension and transport activities. To this end data collected during the EEGLE project are fully analyzed; shoreline erosion rates and texture of the eroded material were collected from various sources and via various methods and are presented for 34 shoreline segments in a uniform format; an Eulerian Particle Tracking formulation that identifies the source and origin of the various particle sizes (open full item for complete abstract)

Committee: Keith Bedford W (Advisor); Carolyn Merry J (Committee Member); Gil Bohrer (Committee Member) Subjects: Civil Engineering; Geophysics; Ocean Engineering; Oceanography

Doctor of Philosophy, The Ohio State University, 2002, Civil Engineering

With the Maumee River/Lake Erie confluence requiring continuous dredging of two permanent bed mounds to remain a viable harbor, the goal of this dissertation is to research the hydrodynamic patterns and sediment transport characteristics under different forcing conditions in the confluence, with the objective of seeking the origin and physics of the two mobile sediment humps in the navigation channel of the river. As an outcome, this dissertation should help provide guidance as to why, when, and how dredging should be done in the region. An integrated three dimensional, hydrodynamic, sediment transport, wave current bottom boundary layer, and wave model is applied to simulate the hydrodynamics and sediment transport. A curvilinear planform grid with 208 by 79 cells in the horizontal direction and 12 sigma layers in the vertical direction is used to cover the whole lake and the 11 km long dredged channel of the Maumee River. After analysis of the existing Lake Erie literature, 18 hydrodynamic and 14 sediment transport application cases are constructed, based on different combinations of the forcing functions on the lake and river. In addition to generating the Lake Erie circulation patterns often described in published literature by other researchers, the hydrodynamic modeling conducted in this dissertation also has obtained new insight on confluence physics. The analysis of the sediment simulation results shows that the hump closer to the Maumee Bay (hump 2) is mainly deposited and sustained by the river bottom sediment resuspension. The upstream hump (hump 1) is mainly deposited and maintained by the riverine sediment deposition. Under steady SW winds, the deposition at hump 1 is the strongest in spring, less so in summer, and weakest in fall; the deposition at hump 2 is in the reversed order. Under steady NE winds, the deposition at hump 1 is the strongest in fall, less so in summer, and weakest in spring; the deposition at hump 2 is in the reversed order.

Committee: Keith Bedford (Advisor) Subjects: Engineering, Civil