Inspect start model

Create a new CATProduct document and insert into it SimpleParamHull.CATPart document as existing component.

The SimpleParamHull.CATPart contains 6 parameters which control the the hull surface and some reference geometry in Reference OpenBody. The parameters' and geometrical elements' names are self descriptive except the following:

• CF and CA parameters are control the extensions of midship section to the forward and aft directions from midship plane.>
• 'Fwd Mid.Section Limit' and 'Aft Mid.Section Limit' points will help to identify changes in hull surface after execution of optimization process.

Create Reference Elements

The first necessary step is definition of Reference Elements. These elements are the forward and aft perpendiculars, midship section, design water line plane, wrapping surface list and margin line.

Fill the Reference Elements panel as shown on picture and click OK. The Reference Elements appears.For more detail instruction please refer to User Guide.

Find new value for Draft

As you can see the current design has Volume displacement about 13500 m3. Lets imagine that you need than volume displacement have to be equal to 12000 m3 and all parameters of hull surface are stay the same except the draft (T).

To find the new T value, you can use Product Engineering Optimizer. Start appropriate workbench and define new Optimization.

After finishing the optimization process you can see that the new value of draft is 6.216m and volume displacement is 11999.656 m3. And hull surface is modified too.

Note: It is obviously, that this task can be solved using CATIA V5 GSD and Part Design Products features. SIC Hydrostatics Analysis give you the gain in saving time of computation about 3-5 times. Please refer to TODO CATProduct to compare performance. There are two ready-to-run Optimizations for two different approaches. Using Sag parameter in Tools/Options you can control desired performance and accuracy of SIC Hydrostatics computation.

Adjust Hull Surface

Now lets imagine, that you have predefined loadcase with given weight 12000000kg and center of gravity with (-3.5m, 0m, 5.0m). After creation of appropriate 'Explicit Load Case' Feature and performing 'Flotation Position' analysis, you can see than ship floats with heel -1.02 deg.

To adjust current hull surface to flotation position without heel you can use Optimizer again. Please refer for following images to problem definition

and constraints definition

Results

The following image demonstrate the results of optimization process.

Summary of changes

• Forward and Aft limits of midship sections have been changed on 6.6m and 6.2m
• Volume displacement is 12000m3
• Flotation position hasn't heel
• Center of gravity and Center of buoyancy have the same value for X coordinate