Propeller pitch ratio effect on propulsion performance of icebreakers
The paper presents results of studies conducted to investigate how pitch ratio of propellers influence propulsion performance of icebreakers in heavy ice. It is examined how these characteristics are influenced by cavitation margin (2nd stage of cavitation). It is shown that in this case the net thrust of series propellers does not depend on the pitch ratio, while for some propeller series the required power may be minimum depending on the pitch ratio. Calculations of the required power versus pitch ratio variations are given for an icebreaker operating in ice.