The Marine Dynamics Research Group conducts a wide range of research on the maneuverability performance of moving bodies in the ocean focusing on ships, including research on new-type ships such as advanced sail-assisted ships and technological development of underwater robots.
In these studies, we conduct various experiments depending on the purpose as follows:
(◎: Head of the Group)
Here, we would like to introduce some research themes being carried out by our group and the recent technical topics.
The good thing about model experiments is that you can directly measure actual phenomena. However, since the model ship is much smaller than the actual ship, even if the model ship is made to have the same shape as the actual ship, the phenomena of the model ship will not necessarily be the same as that of the actual ship. Ship resistance is one of such phenomena. We solved this problem and created a device that can control the apparent resistance of a model ship.
In order to investigate the propulsive performance of an actual ship, a tank test using a model ship with the same geometrical shape is conducted. And when conducting a model test, it is usual to control the motor to keep the rotation speed of the propeller constant. However, the engine speed of the actual ship changes depending on the the load strength. To conduct more "real" model tests, we made a motor that reproduces the actual movement of the engine, and have developed a method to directly check the propulsion performance of an actual ship in a model test by devising a control method of the motor.
Even if the model ship is made to have the same shape as the actual ship, the phenomena that occur in the model ship are not necessarily the same as the phenomena that occurs in the actual ship. The turning motion when steering and the change in speed due to wind and waves is actually one of such phenomena. We found a way to solve this problem and to investigate the actual movement of the ship in an experiment using a model ship.