One Disaster Prevention Method for Shallow-Sea Culture by means of the usage of Wave Energy

Diving rafts for prevention of disaster for shallow-sea culture were made in pursurance of our intention for diving depth and manner, as a result of done the development of apparatus and the experiment of diving raft for three years. These rafts are constituted of catching wave boards and valves to promote diving depth by means of enfeebling water resistance when the raft begin to dive. We repeated the experiments to find the relation among buoyancy degree of raft dimension and angle of boards and raft stability. As the result, we made the better raft as shown Fig. 8. 1. And three connected rafts (type II in Fig. 9. 2 ) was made by making use of reforming in detail on the basis of Fig. 8. 1 type. This type II show better diving depth, therefore it seems easily to apply to sea wave behavior if we try experiments by adopting of law of hydraulic similarity. We proposed equation (4) as theory of relation of wave pressure P・to diving force Ps and a relational diagram (Fig. 2) of diving depth (h) to broken wave height(HT) This diagram shows that there is a high effect to promote broken wave in case of the raft length (1 )is longer than wave length (L) and the perimeter K/h is constant. However for application of this diagram, it must needs put in more detail experiments. Experimental data about relation between generated wave to diving depth Lnd second wave are few because of taking many hours for reforming of diving arrangement. (Received July 1, 1974)