Powering Calculations - Resistance Estimation

The estimation of the ship's resistance is performed in three stages. The first stage is to estimate the bare hull resistance at model scale over a range of speeds using one of ten available empirical methods; the adopted model scale being determined by the chosen empirical method. You may choose the method most appropriate to the design under investigation. The second stage is to scale the model scale bare hull resistance up to ship scale using the 1978 ITTC Performance Prediction Method, References 11 The third stage is to include the ship scale appendage resistance.

If required (see Required Parameters for Resistance Calculation Methods), the wetted surface area, waterplane area coefficient and 1/2 entrance angle can either be specified by you or left for Hydro to calculate according to the chosen resistance prediction method.

The empirical method chosen for the resistance prediction can be corrected with the Resistance Ratios facility, which uses a set of previously calculated resistance ratios based on an actual model test. See Resistance Ratios for further details.