Super cavitating very high speed stealth surface vessel

[Mark Jarvis 2Participant @markjarvis2]

Paul and Bob

What about aircraft retracts????? they would allow the sponsons to lower or raise the hull, would also make the movement equal on both sides.

Or remove the elastic band and replace with threded rod gear driven it would retract and extend the ssponsons and keep them firmly in position.

Mark

[Paul TParticipant @pault84577]

Hi Bob

Nice idea but how would you control the motor so that it remained in sync with the boats forward motion or any rapid acceleration or de-acceleration.

With the elastic band the system is self regulating.

Paul

[Bob Abell 2Participant @bobabell2]

The wings motor would be independent of waterspeed and controlled at any time by the Tranny

Bob

[Len Morris 2Participant @lenmorris2]

Hi Paul,

Simple but not to specification. You've got the hip joints but not the knee joints. Also agree with Bob A, the wings need to be synchronised. They will be all over the shop as drawn.

Took your advice and casted mi mind back to boyhood! Got mi tools out again and mi meccanno and started to make something! Very instructive!

Len

[Paul TParticipant @pault84577]

Bob it sounds intriguing but how can the wings be independent of the boats speed through water?

It is the forward motion of the real boat that dictates the wings movement so the relationship between forward speed and wing position is fundamental.

How can the tranny control the wings without being linked to the boats speed controller?

Paul

[Bob Abell 2Participant @bobabell2]

Major Thom…..Are you telling me that on the full size craft, the Skipper can`t slow down without the wings flopping down?

If the craft is buoyant, it could sail about, fully raised

My suggestion calls for the RC Skipper to use his discression and raise and lower the wings at any time….Regardless of the forward speed

Capt B

[Paul TParticipant @pault84577]

Bob

The sponsons and wings are inextricably linked to the boats forward speed, for the boat to go faster the wings have to move inwards and to manoeuvre at slower speed the sponsons have to be in the correct position in relationship to the forward speed.

The control of the wings has to be linked to forward speed otherwise the hydrodynamic purpose of the wings become redundant, the control cant be left to the whims of the RC skipper as this completely misses the point of the original concept.

Paul

[Bob Abell 2Participant @bobabell2]

Paul

If the sponsons are buoyant……It doesn`t matter where they are on the surface

The model can go fast or slow at any time

I have been assuming that the wing motion is powered btw!

Don`t understand your idea of wing position being important to surface speed?

Bob

[Paul TParticipant @pault84577]

Hi Bob

The easiest way to answer your points is to do another Q & A so here we go.

If the sponsons are buoyant……It doesn`t matter where they are on the surface

The sponsons buoyancy isn't part of the equation as they remain below the surface at all times.

The model can go fast or slow at any time

Yes but the position (angle) of the wings have a direct effect on the forward speed (see below)

I have been assuming that the wing motion is powered btw!

On the real boat I believe the wings are computer controlled and operated by hydraulics…the computer control is linked to the forward motion of the craft.

Don`t understand your idea of wing position being important to surface speed?

As the wings come together they create a ground effect area which allows the craft to travel faster, in effect the wings trap a 'box' of air between the water surface and the underside of the superstructure and the craft rides on this box of air (much like a hovercraft) which permits higher speeds to be achieved.

The angle of the wings also has a direct effect on the efficiency of the cavitation system.

I hope this helps explain why the link between forward motion and wing angle is so important.

Paul

[Bob Abell 2Participant @bobabell2]

If the forward speed needs to be linked to the wing position and Pigs might fly, then use a mixer between the throttle and wing motor

Bob

[mike farrellParticipant @mikefarrell21522]

Hi Paul I have been listening my favourite music when my mind went to the Sponsons shape.Will you be forming the sponsons with wave pierceing and curved shape to the bows to help cut down the resistance to forward movement thus allowing the boat attaining speed quicker ?

Further thought re sponsons ,if a say one or two degree toe in would assist the inward movement of the sponsons with the added bonus of keeping the boat on a straight line with limited drift ?

[Paul TParticipant @pault84577]

Bob

A mixer between the ESC and wing motor creates more problems than it solves as you need to prevent the wing motor from over running which means you end up with upper and lower limit switches and the associated electronics. I hope that you don't mind my saying but this is getting very complicated and adding a lot of 'high up' weight to a boat where the weight has to be kept low.

Michael

The sponsons will be torpedo shaped as they will be underwater all of the time, the wings will be angled slightly inwards to help lift the cabin.

Paul

[Bob Abell 2Participant @bobabell2]

How can the sponsons be under the water for most of the time?

They either sink or swim!

Bob

[Paul TParticipant @pault84577]

Bob

On the Ghost boat the sponsons are under the water all of the time, the propellers are fitted in the front of the sponsons so they have to be submerged all of the time.

Paul

[Bob Abell 2Participant @bobabell2]

Hello Paul

How`s your Three loaves and Five fishes trick, these days?…lol

You can`t have a sponson below the water!…..It either floats or it sinks……You know that yourself

Are you winding us up?……….I`m tellin!

Bob

[Paul TParticipant @pault84577]

Bob

We are having deja vu again.

We have discussed the role of the sponsons (pods / hulls / torpedo shaped things on the end of the wings) before and have already established that they remain under the water without sinking or floating to the surface.

What are loaves and fishes tricks?

Paul

[Bob Abell 2Participant @bobabell2]

Paul has explained to me how he gets the sponsons to stay under water

They are just a part of the wing and the wing has some buoyancy in itself

Sorry Paul for being so critical

I'll shut up now

Bob

[Paul TParticipant @pault84577]

Hello Captain R W Abell cdm, bath plug & bar

Please carry on being critical as it helps Kevin understand some of the projects finer points, I would be the first to admit that from my ivory tower I tend to gloss over points that seem obvious to me but could be very confusing to others.

The problem isn't the lack of buoyancy in actual fact there is too much buoyancy in the sponsons and wings but this will all come out in the design process with the positioning of mass and ballast.

However the initial drawings must be misleading especially if an engineer of Bobs experience cant understand them so I have tidied up one of the drawings to make my intentions clear.

I intend that the sponsons be fixed to the wings with an open (or hollow) connection. 

Aswell as creating a clear access for wires it also changes the way that the buoyancy calculations are carried out.

Instead of calculating the sponsons separately as sealed units the calculations can be done as an entire boat, in this way the boat can be considered as a weird shaped catamaran. 

Bob do you think this better explains the point?  

Paul

Edited By Paul T on 19/01/2015 14:39:23

[Bob Abell 2Participant @bobabell2]

Don't fancy all the aggro with motors and batteries in the sponsons…..Getting wet through!

Have you got an easy solution?

Bob

[Paul TParticipant @pault84577]

Bob

I do have a very elegant solution to getting the motors and batteries in and out of the sponsons which basically involves everything being mounted on an equipment tray and being slid in and out of the sponsons.

The building, fixing and sealing of the sponsons will all be made clear on the next set of drawings.

Paul

[Bob Abell 2Participant @bobabell2]

I`m not going to like this!

Anything that needs sealing…..Spells trouble

Bob

[Paul TParticipant @pault84577]

Bob

Don't underestimate your abilities or my ability to take your abilities into account.

Do you have trouble sealing a normal hull?

Paul

[Bob Abell 2Participant @bobabell2]

No problem sealing a normal hull……But yours is a tube…..O rings?…..screws?….Vaseline?….UGH!

Get it over with!

Bob

[Paul TParticipant @pault84577]

Bob

Neoprene O rings and polytetrafluoroethylene seals……………easy.

Paul

[mike farrellParticipant @mikefarrell21522]

Paul Enjoying the banter but what the heck is polytetrafluoroethyleneMichael

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