Bare Hull Resistance Scaling

The model scale bare hull resistance, estimated in one of the above methods, is scaled up to ship scale using the 1978 ITTC Performance Prediction Method, References 11, in which the total resistance coefficient of a ship without appendages is given by:

where:

is calculated according to the chosen. empirical method.

Form Factor Correction, FFC, of zero has the effect of adopting the Froude scaling method.

can either be specified by you, or calculated according to Holtrop & Mennen, References 1 and 2, where the ITTC 1978 formulation is adapted to give increases in CA for specified hull roughnesses greater than 150 µm.

Hull Roughness values specified by you will only have an effect upon if the Holtrop & Mennen method, References 1 and 2, is specified and the value of hull roughness is greater than 150 µm.

is assumed to be negligible for the types of vessels catered for in Hydro and is set to zero.