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Engine performance
Published in Mohammad H. Sadraey, Aircraft Performance, 2017
The purpose of a variable pitch is to maintain an optimal angle of attack (maximum lift to drag ratio) on the propeller blades as aircraft speed varies. Early pitch control systems were pilot-operated, either two-position or manually variable. The pitch of the propeller may be controlled in flight to provide improved performance in each phase of flight. Following World War II, automatic propellers were developed to maintain an optimum angle of attack (best efficiency). This is usually done via a mechanical governor that continually adjusts the blade pitch angle. This feature of a variable-pitch propeller will provide the pilot with performance advantages, including shorter takeoff run, improved climb performance, improved fuel efficiency, greater range, higher maximum speed, steeper descent, and shorter landing run. At low speed (e.g., takeoff), the prop has the highest pitch angle, while at high speed (e.g., cruise), the prop has the lowest pitch angle.
From data to insight for a polar supply and research vessel
Published in Ship Technology Research, 2019
Anriëtte Bekker, Mikko Suominen, Pentti Kujala, Rosca Johan Oscar De Waal, Keith Ian Soal
The SA Agulhas II (SAA II) is a polar supply and research vessel owned by the South African Department of Environmental Affairs, Figure 1. She was manufactured by STX Finland in Rauma shipyard and measures 121.3 m between perpendiculars and is 21.7 m wide. She is propelled by four Wärtsilä 3 MW diesel generators that power two Conver Team electric motors, which are each connected to a shaft with a variable pitch propeller. Accommodations are available for 44 crew and 100 passengers on annual research and re-supply voyages to Antarctica, Gough Island and Marion Island.