Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. Description based on print version record. Includes bibliographical references.

There is at present great interest in large ships capable of carrying substantial cargo at speeds in excess of 40 knots. At the same time, there are large gaps in our understanding of the hydrodynamics, structural engineering, and economics of high-speed vessels. Monohulls, catamarans, trimarans, surface effect ships, and air cushion vehicles are considered in the present work. The total resistance of these vehicles is divided into separate components which are estimated using different methods. Skin-friction is estimated using Grigson's algorithm which gives much better predictions of flat plate skin-friction than the traditional ITTC method. Wave resistance of displacement hulls is estimated using Michell's thin-ship theory: a similar theory is used for the wave resistance of travelling pressure distributions. Several simple formulae are derived that can be used in the preliminary design stage of catamarans to estimate optimum demihull separation. Memetic algorithm techniques are used to find vessels with minimum (calm-water) total resistance. Optimal geometric parameters are found for vessels of 1200 tonnes under a variety of geometric limitations and constraints on upright stability, at design speeds of 50 knots and 75 knots. Estimates are made of the principal weight components of the optimal vessels. Empirical formulae for the efficiencies of powerplants and propulsors then enable estimates to be made of the maximum range, the cargo capacity, and the fuel consumption. / Thesis (M.Sc.)--School of Mathematical Sciences, 2005.

Department of Chemical Engineering, University of Newcastle, N.S.W. Bibliography : leaves 22-238. "The hydrodynamic phenomena occurring inside the enclosed downcomer section of a plunging jet bubble column are described in this study".

There is at present great interest in large ships capable of carrying substantial cargo at speeds in excess of 40 knots. At the same time, there are large gaps in our understanding of the hydrodynamics, structural engineering, and economics of high-speed vessels. Monohulls, catamarans, trimarans, surface effect ships, and air cushion vehicles are considered in the present work. The total resistance of these vehicles is divided into separate components which are estimated using different methods. Skin-friction is estimated using Grigson's algorithm which gives much better predictions of flat plate skin-friction than the traditional ITTC method. Wave resistance of displacement hulls is estimated using Michell's thin-ship theory: a similar theory is used for the wave resistance of travelling pressure distributions. Several simple formulae are derived that can be used in the preliminary design stage of catamarans to estimate optimum demihull separation. Memetic algorithm techniques are used to find vessels with minimum (calm-water) total resistance. Optimal geometric parameters are found for vessels of 1200 tonnes under a variety of geometric limitations and constraints on upright stability, at design speeds of 50 knots and 75 knots. Estimates are made of the principal weight components of the optimal vessels. Empirical formulae for the efficiencies of powerplants and propulsors then enable estimates to be made of the maximum range, the cargo capacity, and the fuel consumption. / Thesis (M.Sc.)--School of Mathematical Sciences, 2005.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

It is well known that second order effects may in many cases be important for the nonlinear hydrodynamic problems arising in ocean engineering. Despite considerable efforts having been made in the past in calculating second order unsteady forces, similar studies are rare for the actual second order velocity potential itself, which is important for the understanding of wave kinematics. A mathematical model has been developed for the calculation of the second order sum frequency diffraction potential for fixed bodies in waves. It is believed that a first step towards the solution of the second order problem is the accurate evaluation of the first order quantities. By the use of Green's second identity, the first order problem can be cast into the form of a Fredholm integral equation and then solved by the Boundary Element Method. Some new developments based on this technique have been undertaken in this work, and as a result, there is a major improvement in the accuracy of the first order analysis. For the second order problem, the solution procedures are similar to those used for the first order problem except that special techniques have been developed to calculate efficiently the additional free surface integral which decays slowly to infinity in a highly oscillatory manner. In addition, an effective method has also been implemented to calculate the second derivative term in the free surface integral. From the numerical results presented, a number of interesting findings are illustrated. A closed form expression for a vertical circular cylinder has also been developed which not only furnishes a valuable check on the general numerical model but also provides some physical explanation for the second order phenomena. Moreover, it has been used to investigate some theoretical problems which (in the past) have caused confusion and error in the second order analysis. They are mainly associated with the troublesome nonhomogeneity presented in the free surface boundary condition.

No description available.

published_or_final_version / Civil and Structural Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Mechanical Engineering / Master / Master of Philosophy