For the accurate evaluation of the ship performance in actual seas, the relation among ship speed, engine revolution and engine power in calm sea is important. The relation is to be expressed by a numerical model for the application to the analysis for the aging deterioration and the biological fouling. Conventionally these relations are obtained by fitting of the onboard measurement data in calm sea. However when the data in calm sea is few and not distributed in wide speed range, the fitting curve is not appropriate in many cases. And in the case of the evaluation of the ship performance in actual seas for the different displacement, the relation among ship speed, engine revolution and engine power is to be corrected for the displacement.

In the paper, a numerical model for the relation among ship speed, engine revolution and engine power in calm sea and the application of the model to the different displacement are proposed and evaluated by onboard measurement data.