Scaling Factors are those parameters that can be calculated directly using a linear scaling of the hull, namely Displacement, Waterline Length, Waterline Beam and Draft. These parameters can be constrained to particular values, or left to vary as other parameters change by selecting the appropriate check boxes and setting the required values.
As an example, if no scale factors are specified and the Block Coefficient is increased, the displacement will also increase, while the length, beam and draft will remain constant. If the displacement is the only constraint, the length, beam and draft will decrease proportionally to accommodate the redistributed volume. If displacement, length and beam are constrained to particular values the draft will be changed accordingly.
Note
It is not possible to constrain all the values simultaneously – of the four values, displacement, length, beam and draft, at least one must be allowed to vary at all times.
Ø Open the Maxsurf Sample_Trawler.msd file from the sample designs folder on your hard drive.
Ø Save the design to another location with a different filename
Tip: it is generally good practice to save to another filename before doing a parametric transformation or working with the standard sample designs.
Ø Go to Data | Parametric transformation
Ø Specify the following scaling factors and leave the displacement un-constrained:
Ø Press Search and wait for the hourglass to disappear.
Ø Press Ok to accept the new hullshape
Ø Do a Data | Calculate hydrostatics to check the changes have been made correctly.
Note that the displacement has changed, but the LCB % and hull form coefficients are still the same. The draft to baseline is not updated until you specify the new baseline and you may also want to reset your AP and FP in the Frame of Reference dialog to match the new overall dimensions of the hull.
Also see:
· Parametric Transformation Restrictions