On the generation of surfable ship waves in a circular pool: Part I Physical background & Wave pool design

In spring 2006, Sierd de Vries and I were contacted by Professor Stive about an Australian surfboard manufacturer, Greg Webber, searching assistance in the development of a new invention; a circular pool with surfable waves generated by ship-like hulls. Soon the contact was established and it turned out to be an interesting research project. The results of research are documented in two theses. The author strongly recommends the thesis of Sierd de Vries, ′ On the generation of surfable ship waves in a circular pool: Part II, the application of stereo photo technique measuring water surface elevation and surface flow velocities ′. Furthermore the valuable comments and enthusiasm of Steven Schmied, Australian project manager of the wave pool, are acknowledged. in the realisation of the physical model tests. Special thanks go out to my parents, family and friends. You all have been supportive in so many ways. Finally, Sierd, thank you for sharing your enthusiasm and valuable comments. i Summary Surfing as a sport is growing. Locations with good surfing conditions are limited and therefore crowded. The growing interest for the sport led to a new concept, surf pools. Surf pools mimic good surfing conditions found along the coast. This thesis is about the technical feasibility of a new surf pool concept invented by Greg Webber. Webber's invention is to creating surfing waves in a circular pool by towing ship-like hulls around. The hulls are towed along the outer wall of the pool and waves generated by these hulls propagate inwards and break on an island in the middle of the pool. The waves break around the island which theoretically leads to endless surf rides. The initial design as suggested by Webber is based on a pool diameter of 200 m and a water depth of 3 m. The objective of his design to generate 2 m high waves for intermediate to expert surfers. The objective of this study are twofold: 1) understanding the physical phenomena in such a wave pool and 2) evaluating and amending the initial design. Because of the lack of knowledge about ship induced waves in such an enclosed environment, a physical and a numerical model study are carried out. Various hull sizes are towed in a towing tank and the surface elevations are measured and analyzed. From this physical model study it was concluded that the wave pattern behind a hull is the result of …