2.4    Mass calculation

In Entity “Mass calculation” the mass and the centre of gravity of the whole system will be calculated. These values will depend on themass and centre of gravity of both light ship weight and cargo objects. The total mass is calculated by the summation of all mass components (Entities) one level below Entity “Mass calculation”. The centre of gravity of a system of components is defined as the average of their positions, weighted by their masses.

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Figure 79: Entity "Mass calculation"

2.4.1      Light Ship Weight

First include the Entities:

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• Mass = SUM(@QEntity, 1, @Mass) ; The result will be the summation of all parameters “Mass” of the Entities one level below.
• COGX = MOMX/Mass
• COGY = MOMY/Mass
• COGZ = MOMZ/Mass
• MOMX = SUM(@QEntity, 1, @MOMX);
• MOMY = SUM(@QEntity, 1, @MOMY)
• MOMZ = SUM(@QEntity, 1, @MOMZ)
• To show computed values during a dialogue write “@SHOW” behind “QEntityData”.

2.4.1.1     Mass Hull

Create the following parameter in the Knowledge Browser.

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• COGX = ( ENTITY#(xx).Lpp)*0.5 ; for xx fill in the value of QEntityID of Entity ”Main Dimensions”. So we assume the centre of gravity of the hull in X direction half of the ship length.
• COGY = 0 ; Amidships
• COGZ = ( ENTITY#(xx).Dm)*0.45 ; for xx fill in the value of QEntityID of Entity ”Main Dimensions”. So we assume the centre of gravity of the hull in Z direction at 45 % of the moulded depth.
• MOMX = COGX*Mass
• MOMY = COGY*Mass
• MOMZ = COGZ*Mass
• To show computed values during a dialogue write “@SHOW” behind “QEntityData”.
• Volume = ENTITY#(xx).Volume ; for xx fill in the value of QEntityID of Entity ”Hydrostatics”. Make sure to instantiate this parameter and remove @MODIFY because you do not want to allow this at this position.
• Mass = Weight_volume_factor*Volume

2.4.1.2     Mass Decks

Include Entity:

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Figure 81: Entity "Decks" as child of Entity "Mass Decks"

2.4.1.3     Mass Bulkheads

Include Entity:

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Figure 82: Entity "Bulkheads" as child of Entity "Mass Bulkheads"

2.4.2      Mass Cargoes

Include Entity:

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