For the ducted propeller in aeronautics, see Ducted fan.
Not to be confused with Wake-equalising duct.
Kort nozzleThe towboat Dolphin I in a floating drydock on the Mississippi River in Algiers, Louisiana.
A ducted propeller, also known as a Kort nozzle, is a marine propeller fitted with a non-rotating nozzle. It is used to improve the efficiency of the propeller and is especially used on heavily loaded propellers or propellers with limited diameter. It was developed first by Luigi Stipa (1931) and later by Ludwig Kort (1934). The Kort nozzle is a shrouded propeller assembly for marine propulsion. The cross-section of the shroud has the form of a foil, and the shroud can offer hydrodynamic advantages over bare propellers, under certain conditions.
Advantages are increased efficiency at lower speeds (<10 knots), better course stability and less vulnerability to debris. Downsides are reduced efficiency at higher speeds (>10 knots), course stability when sailing astern, and increase of cavitation. Ducted propellers are also used to replace rudders.
A ductedpropeller, also known as a Kort nozzle, is a marine propeller fitted with a non-rotating nozzle. It is used to improve the efficiency of the propeller...
watercraft Ductedpropeller – Marine propeller with a non-rotating nozzle Pump-jet – Marine propulsion system Folding propeller – Propeller with blades...
same way as a ductedpropeller, resulting in improved fuel efficiency. Though the fan creates thrust like a propeller, the surrounding duct frees it from...
thruster. A ductedpropeller is mounted as an integral part of the rudder and is fixed to it. The duct is a Kort nozzle and enables the propeller to develop...
ubiquitous propeller example is a common outboard motor for a small boat. “Pusher configuration” describes the specific (propeller or ducted fan) thrust...
and that it could meet safety requirements.Full-scale testing of the ductedpropeller drivetrain was completed in October 2017.Type certification and commercial...
marine propulsion, uses water as the working fluid, pressurized by a ductedpropeller, centrifugal pump, or a combination of the two. Cephalopods such as...
a system to drop ballast, and a cluster of five, fixed direction, ductedpropeller, marine thrusters at each of the port and starboard ends of the outer...
created the compound helicopter concept of vectored thrust using a ductedpropeller. Born in Philadelphia, Pennsylvania, to an immigrant Polish tailor...
different shapes and sizes, for example screw propellers, Voith-Schneider propellers, waterjets, ductedpropellers, tunnel bow thrusters, and stern thrusters...
Azimuth thruster – Steerable propulsion pod under a watercraft Ductedpropeller – Marine propeller with a non-rotating nozzle Kitchen rudder – Type of directional...
of propulsion. A pump-jet, hydrojet, water jet, or jet drive uses a ductedpropeller (axial-flow pump), centrifugal pump, or mixed flow pump to create a...
demonstration contract to serve as a testbed to validate the "Vectored Thrust DuctedPropeller" system. Piasecki developed and flight-tested the X-49 experimental...
Azimuth thruster – Steerable propulsion pod under a watercraft Ductedpropeller – Marine propeller with a non-rotating nozzle Kitchen rudder – Type of directional...
developing the ductedpropeller, or Kort nozzle. In an attempt to reduce canal erosion, Kort discovered that directing the wake of a propeller through a short...
system that uses a jet of water. The mechanical arrangement may be a ductedpropeller with nozzle, or a centrifugal compressor and nozzle. The pump-jet must...
and aerodynamic lift and is powered by four diesel engine-driven ductedpropellers. The HAV 304 was originally built for the United States Army's Long...
JEFF B by Bell Aerospace JEFF A had four rotating ductedpropellers JEFF B had two ducted rear propellers similar to the proposed SK-10 which was derived...
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