Search results
Results from the WOW.Com Content Network
Kort nozzle The 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 ...
The Kort nozzle is a sturdy cylindrical structure around a special propeller having minimum clearance between the propeller blades and the inner wall of the Kort nozzle. The thrust-to-power ratio is enhanced because the water approaches the propeller in a linear configuration and exits the nozzle the same way.
Ludwig Kort (1888 - 1958 [1]) was a German fluid dynamicist known for developing the ducted propeller, or Kort nozzle. In an attempt to reduce canal erosion, Kort discovered that directing the wake of a propeller through a short, stationary nozzle also increased thrust. [2] He submitted a U.S. patent for this technique, which was awarded in ...
Azimuth thrusters on the tug Oued el Kebir - note the Kort nozzles. There are two major variants, based on the location of the motor: [citation needed] Mechanical transmission, which connects a motor inside the ship to the outboard unit by gearing. The motor may be diesel or diesel-electric.
As originally built, Mohawk had two controllable-pitch Kort-nozzle propellers for propulsion. She had two 20-cylinder Diesel engines, GM EMD 20-645F7B, [4] which provided 4,500 shaft horsepower. These would drive the ships at 15 knots. She also had a 300-horsepower bow thruster to improve maneuverability. [2] [5]
Their kort-nozzle allows for a greater bollard pull however it loses its pull at anything over 10 knots (19 km/h; 12 mph) and loses speed in turns. [3] The Ville class are 13.71 m (45 ft 0 in) long with a beam of 4.72 m (15 ft 6 in) and a draught of 2.74 m (9 ft 0 in).
The Kort nozzle, pump-jet and rim-driven thruster are examples. An example propulsor is shown in the accompanying picture. It has a shroud which cuts down on blade-tip cavitation and radiated noise. It also has a rotor element and a stator. The stator concentrates the thrust in axial direction and reduces energy wasted in the tangential flow ...
The Z-drives have four-bladed propellers which are 57.1 inches (145 cm) in diameter [9] and are equipped with Kort nozzles. They can be operated in "tiller mode" where the Z-drives turn in the same direction to steer the ship, or in "Z-conn mode" where the two Z-drives can turn in different directions to achieve specific maneuvering objectives.