In the previous sections opening and preparing a model in Hydromax was discussed together with descriptions of the different Analysis types. This section will describe the following analysis settings:

§   Heel

§   Trim

§   Draft

§   Displacement

§   Specified Conditions

§   Permeability

Hydromax will allow specification of only those analysis settings that apply to the currently selected analysis type.

In hydrostatic analysis, there are three degrees of freedom: Trim, Heel and Draft.  Hydromax matches the trim, heel and draft with the vessel’s mass and centre of gravity or visa versa. This way the volume of the displaced hull matches the required mass and the centres of gravity and buoyancy lie one above the other in a vertical line. For example: it can match a specified heel, trim and draft by varying the displacement and centre of gravity; or it can match a specified displacement and centre of gravity by varying the heel, trim and draft. Combinations of both are also possible. The following table is a very simplified representation of the degrees of freedom and their weight counterpart:

In fact it is a rather more complicated situation than that suggested by the table above, because vertical centre of gravity is also important and also because most of the variables are coupled.

The various analysis types and settings can be thought of as setting one variable in each pair to a fixed value and deriving the others from the analysis.

For example: the Upright Hydrostatics analysis consists of fixing heel and trim and stepping through a series of fixed drafts. In this case the LCB and TCB (and therefore the required LCG and TCG) are calculated from the underwater hullshape at each draft. For an equilibrium analysis all degrees of freedom are derived from the centre of gravity and Displacement. In the Specified Condition Analysis any combination of the variable pairs may be specified.