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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 ...
In aeronautics, a ducted fan is a thrust-generating mechanical fan or propeller mounted within a cylindrical duct or shroud. Other terms include ducted propeller or shrouded propeller . [ 1 ] When used in vertical takeoff and landing ( VTOL ) applications it is also known as a shrouded rotor .
A rim-driven thruster integrates an electric motor into a ducted propeller. The cylindrical duct acts as the stator, while the tips of the blades act as the rotor. They typically provide high torque and operate at low RPMs, producing less noise. The system does not require a shaft, reducing weight.
Rim–driven thruster, presented at SMM 2010 A rim-driven thruster mounted on a swing-out unit (design by silentdynamics GmbH) Voith rim thruster at SMM 2010 in Hamburg. The rim-driven thruster, also known as rim-driven propulsor/propeller (or RDP) is a novel type of electric propulsion unit for ships.
Unlike ducted engines, rockets give thrust even when the two speeds are equal. In 1903, Konstantin Tsiolkovsky discussed the average propulsive efficiency of a rocket, which he called the utilization ( utilizatsiya ), the "portion of the total work of the explosive material transferred to the rocket" as opposed to the exhaust gas.
If you are concerned about yourself or a loved one, call the Substance Abuse and Mental Health Services Administration's (SAMSA) confidential, free, 24-hour-a-day, 365-day-a-year helpline at 1-800 ...
If you suspect child abuse, call the Childhelp National Child Abuse Hotline at 1-800-4-A-Child or 1-800-422-4453, or go to www.childhelp.org. All calls are toll-free and confidential. The hotline ...
Read no further until you really want some clues or you've completely given up and want the answers ASAP. Get ready for all of today's NYT 'Connections’ hints and answers for #579 on Friday ...