The Directional Spectrum Water Wave Generator for Towing Tanks

Abstract

Recently, the directional spectrum water wave generator for long tanks has been developed and established at the Experimental Tank of Yokohama National University, (Length 100m, Breadth 8.0m, Water draft 3.5m). 16 unit wave generators were installed on a short wall of the long tank. This wave generating system is based on a new concept to generate the specified directional spectrum water waves. Reflection of waves on the sidewalls, that has been always recognized as a bad phenomenon for a good wave generation, is utilized positively for generating the specified directional spectrum waves to propagate in the long tank. For this new system, the unit wave generator, the electronic control system and soft wares for wave generating signals were newly developed in Yokohama National University. By the use of this system, successful directional spectrum waves were obtained in the almost all zone of the long tank on both lengthwise and widthwise. It means that the running model test in specified directional spectrum waves is possible. On the other hand, the generation of directional spectrum waves by this system is restricted to have the symmetric directional spreading function and propagate along by the long tank.