Development of the Analysis Method on Unsteady Hydrodynamic Forces Acting on Berthing Ship

The unsteady hydrodynamic forces acting on a berthing ship model was examined, and an procedure for the analysis of measured result in towing tank was considered. The blockage effect could be a problem if we execute the large attack angle lateral force measurement in towing tank, and it will be much serious in the case of shallow water. The authors proposed an experimental procedure, which enables us to carry out the test in towing tank. The proposal employ the normal size model ship with the resistance test, and the blockage effect was avoided by towing the model normal to the tank length. The additional problems in connection with the side wall of towing tank was considered as well. The refected waves affect on the measurement, and it causes unstediness. The authors consider the analysis process on that factor, and they proposed practical solution to extract steady component.