A Study on the Reynolds number dependency of the Form Factor of a Ship

초록

Since the basis of Froude’s law is adopted in the model tests and the numerical simulations of ship resistance, the form factors of the model and the full-scale ship could be different. It is caused by the difference of the Reynolds number each other. Therefore, when effective powers and delivered powers of the full-scale ship are predicted according to each model size, the effective powers and delivered powers could be different. Furthermore, in a relative small towing tank, the size of the model is too small, so the power prediction error of full-scale ship could occur largely due to the difference of the Reynolds number between the model and the full-scale ship. In this study, a prediction method of form factor for full-scale ship is suggested to minimize the power prediction error from small model ship. The numerical simulations are carried out in various Reynolds numbers from small model to full-scale ship. The variation of the form factors is investigated from the results of the numerical simulation according to Reynolds numbers. And then the results of the numerical simulations and the experimental data of geosim models utilize to drive the correlation line to predict the form factor of a full-scale ship. The correlation line is applied to the prediction of the effective power and the delivered power of a full-scale ship. As a result, the developed prediction method confirmed the possibility of the predicted power reliably from the experiment using small model.