Two-dimensional impact theory extended to planing craft with experimental comparisons.

The topics covered by this dissertation include extensions to existing two-dimensional impact theory, full-scale planing experiments, hydro-elastic experiments, and calculation methods for the free contour between a separation point and the spray jet of chine wetted, two-dimensional impact. Two extensions to the existing flat cylinder impact theory of Vorus (1996) are presented. Modifications are made to the kinematic boundary condition and the complete derivation of the resulting vortex strength distribution is given. Various parameters of the theory are compared based on the differing problem formulations. The added mass coefficients are compared to the predictions of other researchers. A series of full-scale planing experiments were performed in which the hydrodynamic pressures were measured using static pressure manometry. The experimental data is compared to the slender body extensions of two of the impact models developed in first section. A brief analysis of the results is given. A three-year research effort into shock mitigation of planing boats developed a novel concept by which the hydrodynamic forcing functions can be significantly reduced. This research culminated with a series of hydro-elastic drop test experiments that indicated that the underlying concept is valid. The experimental acceleration time histories for various configurations of the concept are compared to the theoretical predictions. Finally, a number of calculation methods are presented for predicting the free contour displacement between a separation point and the spray jet in two-dimensional impact. The predicted contours resulting from the calculations are shown, however the results are not physically reasonable. Several potential sources for the shortcomings are identified. Additionally, a new relation for conservation of mass is developed for use in the separation problem.Ph.D.Applied SciencesOcean engineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/126377/2/3016946.pd