3.2 Model set-up
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1200 – Interim Guidelines for Alternative Assessment of the Weather Criterion – (24 May 2006) - Annex - Interim Guidelines for Alternative Assessment of the Weather Criterion - 3 Guidelines for Experimental Determination of the Wind Heeling Lever Lw1 - 3.2 Model set-up

3.2 Model set-up

Parent topic: 3 Guidelines for Experimental Determination of the Wind Heeling Lever Lw1

3.2.1 Ship model used for wind tests

 The model should copy the above-waterline shape of the actual ship and should comply with the following:

  • .1 the overall length should be at least 1.25 m;

  • .2 all sharp corners in the actual ship should be sharp in the model to simulate separated flow;

  • .3 main fittings on the exposed decks and superstructures, e.g. cranes, masts, bulwarks, should be modelled and fitted properly;

  • .4 the size of the model should be determined to make the blockage ratio to the wind tunnel less than 5%, where the blockage ratio is defined as the ratio between the lateral projected area of the model above the waterline divided by the area of the test section of the wind tunnel; and

  • .5 when a blower is used the ship should be within the area of uniform wind speed.

3.2.2 Ship model used for drifting tests

 The model should copy the under-waterline shape of the actual ship and should comply with the following:

  • .1 the size of the model should comply with paragraph 4.3.2;

  • .2 not only underwater fittings (e.g. bilge keels, rudders, etc.) but also potential underwater part when the ship heels (e.g. bulwarks, freeing ports, etc.) should be modelled and fitted properly.

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