Study on the form factor and full-scale ship resistance prediction method

To consider the resistance component due to hull geometry, the International Towing Tank Conference (ITTC) adopted the resistance test method in 1978, introducing the form factor concept with two basic assumptions, i.e., the form factor of a model ship is the same as that of a full-scale ship and the form factor is independent of ship speed. However, it is not only very difficult to determine the form factor using the ITTC ’78 method, but also there have been questions regarding the basic assumptions. Therefore, the authors carried out three basic studies on the form factor concept and proposed a new extrapolation procedure for the prediction of full-scale ship resistance performance. The validity of the proposed procedure is being investigated by comparing sea trial and model test results. The results of this investigation will be presented in the near future.