Kunihiro Ikegami

Response Characteristics of the Floating Water Purifier “Water Beetle” in Waves

In closed water areas such as reservoirs and ponds, the water quality is prone to deteriorate when water flowing into the area is polluted and over-rich in nutrients. This causes algae to increase. The Water Beetle is a floating water purification unit on new principle to have the high performance with small energy. When the Water Beetle is used in a water area of complicated shape, plural miniaturized units are arranged to adjust the shape of area and connected to each other by use of mechanical connecting devices. To design the mechanical connecting device, it is necessary to grasp the exact response characteristics of the Water Beetle connected to each other in waves. A model basin test was conducted for the Water Beetle connected to each other in waves. In the model basin test, three floating unit models of the Water Beetle were connected by mechanical connecting devices that were simplified. The test was carried out to vary the connecting mechanism at connecting points. The measured results were compared with the calculated results obtained by use of the calculation method for motion analysis of multiple bodies connected to each other in waves, and they were compared between various connecting conditions to evaluate the most suitable connecting condition. As the result, the characteristics of response of the Water Beetle connected to each other in waves were obtained experimentally and theoretically, and the most suitable connection mechanism of connecting device was able to be decided. Therefore, the realization of the multi-connected Water Beetle system was confirmed experimentally.Copyright

Response Characteristics of a Trailer Type Multi-Connected Barge System in Waves

A trailer type multi-connected barge system is a new type of ocean transportation system composed of several barges connected to each other with a mechanical connecting device and a tug ship. To design the trailer type multi-connected barge system, it is necessary to grasp the exact response characteristics of the trailer type multi-connected barge system in waves. A model basin test was conducted for the trailer type multi-connected barge system in waves. In the model basin test, the tug ship and three barges were connected to each other by the mechanical connecting device, and the tug ship towed three barges in waves. As a result, the response characteristics of the trailer type multi-connected barge system in waves were obtained. A non-linear phenomenon of a longitudinal connecting force caused by relative pitch motions of barges was observed. A way to avoid the non-linear phenomenon and reduce the longitudinal connecting force could be found, and the realization of the trailer type multi-connected barge system was experimentally confirmed.Copyright

Response Characteristics of a Multi-Connected Floating Body System in Waves

A multi-connected floating body system composed of many connected small-scale floating body units has a number of advantages with regard to construction and performance compared with a united floating body. To design the multiconnected floating body system, it is necessary to grasp the exact response characteristics of the multi-connected floating body system in waves. A model basin test and a theoretical calculation were conducted for the multi-connected floating body system in waves. In the model basin test, three floating body unit models with a regular hexagonal water plane were connected to each other with a newly conceived mechanical connecting device. As a result, the response characteristics of the multi-connected floating body system in waves were clarified experimentally and theoretically, and the applicability of a theoretical calculation method was experimentally confirmed.Copyright

Development of Multi-Connected Floating Body System

A multi-connected floating body system composed of many connected small-scale floating body units has a number of advantages with regard to construction and performance. To realize the multi-connected floating body system, a new type of mechanical connecting device was developed. It is composed of multi-degrees of freedom connecting mechanism and restricting mechanism to control a restricting condition between floating body units, and its effectiveness was confirmed by model basin test in waves. Next, friction and wear tests in the seawater environment led to the discovery of suitable materials for oscillatory sliding parts in multi-degrees of freedom connecting mechanism. Finally, a field test performed for two floating body units connected by use of the mechanical connecting device proved that the developed mechanical connecting device was of practical use.Copyright