A ducted propeller, also known as a Kort nozzle, is a marine propeller shrouded 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.

Designs have been made for controllable pitch propeller blades for Kort nozzle operation up to 5300mm diameter. Kort have also supplied high definition propellers and impellers for high speed craft with conventional propulsion, surface piercing drives and waterjets.

The Kort nozzle is a shrouded, ducted propeller assembly for marine propulsion. The hydrodynamic design of the shroud, which is shaped like a foil, offers advantages for certain conditions over bare propellers.

Kort, recognizing that the propulsive efficiency of the screw propeller could be improved by the guard or nozzle, concentrated his effort on designing a nozzle for this purpose. At first, the problems were many.

Dec 16, 2024 · Kort nozzles offer several advantages, including increased thrust and efficiency, improved manoeuvrability, reduced fuel consumption, and enhanced propeller protection and stern strength. Additionally, Kort nozzles can help to …

Kort Nozzles & Propellers The advantages of Kort Nozzles are well known for towing vessels such as tugs and fishing boats. However, significant improvements in performance can be achieved on vessels such as coasters, inland waterways craft and bulk carriers using designs optimised f or each vessel type. The key to vessel performance lies in

May 23, 2024 · The Kort nozzle is a low speed, ducted propeller design used on ships and boats consisting of a conventional propeller housed within a specially designed shroud. The shroud's flow accelerating effect and hydrodynamic inner profile greatly improve the thrust efficiency of the propeller at lesser speeds.

Designs have been made for controllable pitch propeller blades for Kort nozzle operation up to 5300mm diameter. Kort have also supplied high definition propellers and impellers for high speed craft with conventional propulsion, surface piercing drives and waterjets. Propellers for azimuthing units and tunnelthrusters are designed and supplied ...

Feb 1, 2007 · The Kort nozzle is a shrouded, ducted propeller assembly for marine propulsion invented by Ludwig Kort. The hydrodynamic design of the shroud, which is shaped like a foil, offers advantages for certain conditions over bare propellers.

Jan 27, 1999 · Kort designed a whole series of ducted propellers which proved very valuable when used in ships like tugs, pushboats, supply ships, trawlers etc. For this reason, his designs became known as Kort Nozzles.