PROCEDURE FOR SELF-PROPELLED MODEL TESTING OF VESSELS IN TEST ICE POOL Russian patent published in 2010 - IPC G01M10/00 B63B9/02 

FIELD: test engineering.

SUBSTANCE: invention refers to experimental studies in ice test pools and can be implemented for designing screw-steering complexes of vessels and facilities for their protection from ice by means of model experiment in pool under created conditions similar to natural. The procedure consists in preparing a field of model ice and in testing a model with operating propellers by means of towing the model or at its free motion at specified speed and at specified frequency of propeller rotation; testing consists in recording frequency of submerged ice cakes meeting a propeller-steering complex and other facilities external relative to the case of the model when ice protection of the model case is present or absent. Also density of model ice is measured. Further, the vessel model is towed in not destructed ice cover with turned off propellers and at speed determined by model-prototype relationship. There is measured average dimension of ice-cakes and width of channel behind the model formed at model passing through ice cover. Ice cover in not destructed ice field strip before the model, the width of which is equal to width of channel after the model, is cut into separate tightly adjoining blocks of ice. Dimensions of blocks are equal to measured average dimensions of ice cakes. The test is carried out in such made channel by means of towing the model with operating propellers. Notably, speed of model towing during the said test is less in comparison to model-prototype relationship speed determined with consideration of water and ice density. Frequency of propellers rotation is set to facilitate correspondence of speed of liquid in the stream behind the propeller to a value determined considering speed in the stream behind the propeller under natural conditions. During testing model under mode of free self-propelling rotation frequency of propellers is specified to ensure correspondence of speed of liquid in the stream behind the propellers under dockside mode to value determined with consideration of speed in the stream behind the propeller at dockside mode under natural conditions.

EFFECT: upgraded validity of test results by means of approaching them to natural conditions.

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