Elica Autoprop 3 pale

[prop]

(26-01-2015 09:33)Nessuno 38 Ha scritto:  ...
E' la famosa teoria figlia di n.n. che induce a sfruttare la coppia max del motore ... a spese della sua durata. Vedi ad es.: il 3ad "Motore diesel rendimento" di gceve.

Nn:
FAO Fisheries and Aquaculture Department and completed under the supervision of Ari Gudmundsson, Fishery Industry
Officer (Vessels), Fishing Operations and Technology Service.

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Nn:
The reality is that an engine can be safely over-propped so long as it is not run at wide-open throttle for more than a few minutes at any given time.
On many vessels, especially displacement vessels, the engine is rarely, if ever, run at WOT.
A combination of overpropping with some mechanism to prevent operation at WOT, or instrumentation to indicate when the engine is being driven too hard, would yield significant efficiency benefits at the propeller and the engine.
It is interesting that Volvo Penta accepts a degree of over-propping with some of its recent engines, recommending propellers be sized such that the maximum engine speed is somewhat below the rated maximum speed.

Nigel Calder is the author of Boatowner’s Mechanical and Electrical Manual and other marine titles (including, earlier in his career, Marine Diesel Engines), and is a member of the American Boat & Yacht Council’s Electrical Project Technical Committee.