Interaction of free surface flow with solid obstacles and porous media

This dissertation presents a new numerical simulation methodology of fluid-solid interaction in complex geometries. Advances have been made in the solution methods for the Navier-Stokes equations, leading to the development of a new technique named Eulerian-Lagrangian Marker and Micro Cell (ELMMC).;The ELMMC technique is capable of simulating incompressible fluid flows in Cartesian coordinates where the free surface can undergo severe deformations, including impact with solid or porous boundaries, impact between converging fluid fronts, and breakup of a fluid front from the main body of the fluid. In order to accurately model wave impact with a dry porous medium, a new impact boundary condition has been developed. The method is also capable of simulating mass transfer processes and accounting for turbulence with a k-epsilon model.;The free surface is tracked by the use of massless Lagrangian markers, while the flow field is calculated in a fixed Eulerian system. The primitive variables are defined on a staggered grid. Surface cells and their neighboring full cells are subdivided into smaller cells, named micro cells. These micro cells, in conjunction with the surface markers, make it possible to prescribe free surface boundary conditions right on the free surface.;The capabilities of the new method are demonstrated by comparing numerical results to experimental studies. Comparisons for the velocity field and the net force that act on a structure being impacted by a wave are favorable. A study is presented that involves the protective properties of different tsunami mitigation schemes with both solid and porous obstacles of different shapes and configurations. Porous obstacles are found to be superior to impermeable obstacles.;Two experimental studies are used to validate the immiscible and miscible modules from the ELMMC method. The first study addresses the natural oscillations of a water-oil interface while the second study considers the mixing of miscible fluids in a stationary and in a rocking tank. Good results are obtained for all miscible fluids considered and for immiscible liquids whose densities differ by less than 10%.*.;*This dissertation includes a CD that is compound (contains both a paper copy and a CD as part of the dissertation). The CD requires the following applications: Windows, DOS, SGI or SUN.