2008年10月29日 · Wherever there is a need for high static thrust or near-static thrust, a shrouded prop is a valid option. Some studies indicates that a properly designed shroud (or duct) can double the static thrust of the prop, compared to the free-tip case. A typical case for this are tug boats, for example, or bow and stern thrusters.

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 ...

2011年1月31日 · The MK 48 torpedo(USA'a operational to 2025) uses a full shroud around its multiple propellers. Its speed is 120 knots (more or less but it outruns submarines and they are fast! If you think the shrouding slows them down you are seriously not thinking very clearly at all.

2004年9月14日 · Anyone here have any experience with propeller protection/shrouds on outboard engines. I'm concerned both with reducing the risk of injuring people in the water, and protecting the propeller from debris. Do they really work, or are they just an unnecessary hassle? All depends on what you mean.

2024年2月6日 · The shroud generates a drag proportional to the square of the speed of the ship. Above a certain speed of evolution, gain efficiency losses in the end of the blades, will be destroyed by the drag generated by the shroud. The shrouded propeller is therefore suitable for low speed vehicle. shrouded fans propellers:

2011年8月17日 · It is a nozzle or propeller shroud depending on what it does. A shroud generaly is to protect the prop or humans and is designed for minimum drag. Nozzles can either be accelerating or decelerating depending on what you need; i.e. high thrust/low speed or high thrust/high speed.

2015年2月3日 · The little 4 bladed Motor guide prop that should have the prop with the least calculated thrust actually is the most practical if you bought your boat to fish where Bass live. In open water and continuous high motor speeds, 13" is great.

2010年11月23日 · Take a couple of spare split pins for the prop to shaft connection (they are designed to break on impact) and you will be able to go anywhere the boat hull will float. Take the little motor with you to the next boat for the dinghy or …

2011年6月13日 · Hoping someone may have some experience with a prop shroud. I've seen a couple boats with sheet metal around the exterior of the cage hoops, and it was stated that this was done in an effort to help silence the prop noise some. Does anyone have first hand knowledge if this actually works ?

2010年7月29日 · 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.