All Hydromax calculations are performed in the frame of reference of the model. Hydromax uses the APP and FPP together with the baseline and the zero point for all calculations and gives the results in the units specified in the display menu.
Note:
Before you run any analysis using Hydromax, it is important that you set up the required initial conditions for the design.
Hydromax uses the Maxsurf coordinate system:
|
+ve forward |
-ve aft |
|
+ve starboard |
-ve port |
|
+ve up |
-ve down |
|
View window |
View direction |
|
Body plan |
From the stern, looking fwd |
|
Plan |
From above, Port side above the centreline |
|
Profile |
From Starboard, bow to the right. |
It is essential that a frame of reference be specified. This should be done in Maxsurf and not in Hydromax. Draft and trim are measured on the forward and aft perpendiculars. If these are not in the correct positions, some analysis results will be meaningless.
See: Setting the Zero Point and Setting the Frame of Reference on page 20.
Note:
Changing the zero point in Maxsurf will not update the compartment definition, loadcase and other input values. Changing the zero point after you have started analysing the model in Hydromax is not recommended.
In Hydromax you may choose between the length between perpendiculars and the waterline length for the calculation of Block, Prismatic and Waterplane Area Coefficients.
The LCB and LCF can be displayed in the Results windows relative to the specified Zero Point, Amidships location, Aft Perpendicular, Fwd Perpendicular or from the Aft, Middle or fwd end of the actual waterline. You can also specify whether you want the forward (towards the bow) or the aft (towards the stern) to have a positive sign. Finally you can chose whether you want the LCB and LCF to be displayed as a length or as a percentage of the waterline or LPP length as specified in the Length for Coefficients.
The units used may be specified using the Units command. In addition to the length and weight (mass) units, units for force and speed (used in wind heeling and heeling due to high-speed turn etc. criteria) and the angular units to be used for areas under GZ curves, may also be set. The angular units for measuring heel and trim angles are always degrees. Units may be changed at any time.
See:
Fluids Analysis Methods on page 100