GHS Wind Heeling for Drilling Units

The Band method of deriving wind-heeling moments from the vessel geometry is applicable to complex models and variable wind direction. Shielding within Parts is assumed. Shielding between Parts is a user-controlled option.

Although shape factors are available on the Component level, this method does not look at panels or analyze drag based on panel orientation. It uses the projected area of the solid-model geometry, projected parallel to the waterplane, in the direction if the wind. The Shape Factor and Effectiveness Factor (which may be assigned to each component by the user) are multiplied together and used to multiply the projected area of the component. When a component is shielded in partially or entirely by another, these factors are averaged for the shielded portion. In other words, it does not matter whether component A is in front of or behind compoent B. The net projected area will be the same either way.

Because of these abstractions, wind heeling moments derived using this method are not to be considered a replacement for experimental analysis or more rigorous analytical methods. However, because it is easy to apply, it may be useful in preliminary design work.

Drilling Unit example

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