What is the purpose of the shrouds around

[novagator]

the propellor/propulsors like the seehund, seawolf, some ROVs?


Other than prevent stuff from hitting the prop, like ice.

[koeze]

They improve efficency of the

They improve efficency of the prop by about 20%. This is also the reason you see these devices on tugs an stuff like that. Some rov's actually steer with them. They are hinged in 2 or even 4 directions and the operator can direct the thrust of the propellor into a certain direction.

EJK

[adriaticsea]

Hi Novagator,

Koeze is correct in

Hi Novagator,

Koeze is correct in saying that these shrouds improve propeller's effciency, but, especially on militar submarines, they also reduce the prop's noise(in this case they're called "pumpjets") , thus making the submarine more difficult to detect by passive sonar.
BEST REGARDS ADRIATICSEA

[kd6hq]

If you make the nozzle

If you make the nozzle moveable it will increase the maneuverability considerably. Some tug boats use what is know as a Kort Nozzle. They nozzle can rotate a minimum of 90º and if you put 2 on – one on the bow and one on the stern then the craft can spin on it’s axis. My tug has one on the stern; the tug is 47” long and can to an 180º turn in about 6 feet. So here’s the challenge – make on fully functional on your sub so that you can effectively do thrust vectoring. Then do away with your stern planes and rudder.

[Guest]

I read somewhere that the

I read somewhere that the original reason for designing the kort nozzle,was to help prevent canal/river bank erosion from propeller wash evident with conventional rudder designs.

The extra efficiency and better turning capability was a very welcome side effect.

Andy