Water jet Manouvering thusters

I am workng on an autonomous  boat that can dynamically hold position using gps. the key to making it work was discovering car windscreen washer pumps with dual outlets. these pumps can be found online for less than £10 and run best at 12-15v. basically if you spin them one way it comes out one nozzle, spin it the other way and it comes out the other one, this is originally used for a cars front and rear window washer but it works ideal as a high-pressure water jet manoeuvring system without any external propellers or drives that can snag, i though this might be usefull to anyone wanting a compact way of adding bow and stern thrusters to their submarines. I originally started using car washer pumps on my nitro boats years ago for when the engine cut out on the pond I could use it as an auxiliary jet drive to make it back to the side of the pond. Because it used 6mm water inlets and 4mm outlet there was very little extra drag.

Interesting approach.

Would the water jet provide more thrust if it discharges into water?

The jet discharging over the rudder is interesting too. Does it reduce the turning circle?

Another use for these would be for model subs at exhibitions (Yes - exhibitions are back e.g Blackpool.)

Display ponds are small and many subs have poor turning circles. You get my drift.

David

david f wrote:Interesting approach.

Would the water jet provide more thrust if it discharges into water?

The jet discharging over the rudder is interesting too. Does it reduce the turning circle?

Another use for these would be for model subs at exhibitions (Yes - exhibitions are back e.g Blackpool.)

Display ponds are small and many subs have poor turning circles. You get my drift.

David

As far as I know discharging the jets will give the same force above or below the surface as your not pushing against the water but using the expelled water as reaction mass. in my videos the boat is almost empty so they are well above the surface but should be just below the waterline when loaded up.

the jet of water directly onto the rudder should give the effect of vectored thrust, giving the rudder more authority especially at low speed. there is also another outlet for reverse at the front of the keel.


this is a full sized version that i found.

i made a small video to show it manoeuvring, once the deck is on and its fully loaded the thrusters will be underwater and barely visible.