SIMULATION OF IMPACTS OF FLUID FREE SURFACES WITH SOLID BOUNDARIES

Deficiencies associated with the simulation of impacts of fluid free s urfaces with solid boundaries by use of marker-and-cell methods are id entified and addressed. New procedures are introduced that affect the movement of markers in cells adjacent to a solid boundary, the flags o f the cells that comprise a solid boundary and the pressure boundary c ondition for a cell in which impact occurs. Combined with fundamental changes in the sequence of steps in the computational cycle, these new procedures allow the intentional treatment of impact. As a result, im proved estimates are obtained of the pressure associated with the cell s adjacent to a boundary along which impact occurs. Consequently, more appropriate adjustments are made of the tentative internal velocities associated with such cells. In addition, a special procedure is prese nted for the adjustment of the tentative internal velocity between two surface cells. Finally, a new cell type termed a comer cell is define d and a procedure for its treatment is presented. Numerical examples a re included to illustrate the previous deficiencies associated with th e simulation of impact as well as the effectiveness of the new methods presented in this paper. Validation of the new methods is achieved by comparison with experimental results for spillage over a containment dike.