Coanda Effect

[redboat219]

David,

Would it be possible to incorporate the Coanda Effect (http://en.wikipedia.org/wiki/Coanda_Effect) on the Seaview instead of bow planes to negate the pitch down attitude induced by the manta rays during submerged running as sort of a Circulation Control Wing http://en.wikipedia.org/wiki/Circulation_control_wing

You could either use a small water pump or bleed off from the pumpjets to force water through slots on the top leading edge of the manta rays to produce lift.

Romel

[He Who Shall Not Be Named]

David,

Would it be possible to incorporate the Coanda Effect (http://en.wikipedia.org/wiki/Coanda_Effect) on the Seaview instead of bow planes to negate the pitch down attitude induced by the manta rays during submerged running as sort of a Circulation Control Wing (http://en.wikipedia.org/wiki/Circulation_control_wing)?

You could either use a small water pump or bleed off from the pumpjets to force water through slots on the top leading edge of the manta rays to produce lift.

Romel

Romel,

Get your head out of those books about Canadian flying-saucers, will ya (search for, 'silver bug' or, 'project omega')!

Seriously though, fluid control is a viable means of producing forces analogous to those of moving control surfaces. But its a matter of plumbing, isn't it? To capitalize on the Coanda phenomena I would have to come up with where to put the injection ports, how to pressurize and direct the water to the ports, and how to integrate that with control surface deflection signals.

The second-stage of the A-3 Polaris missile employed the Coanda effect for thrust vectoring (I was a Launcher Tech on the WEBSTER), so I am familiar with the principle. And that phenomena was the reason early torpedo launcher systems suffered from torpedo impacts against shutter doors (I was a Torpedoman) was later attributed to the Coanda effect.

Even a simplified system, directly coupled to the propulsor output as you suggested, involves a lot of experiment and plumbing. I had not even thought about it. But, it would be too much of a chore to implement properly. Maybe someone else will read this and give it a try, Romel.

You know you're ****, Romel. I'll give you that.

But, as I said: as a practical matter, fluid manipulation through injection is viable, but impractical for we simple r/c submarine types.

David,

[junglelord]

I think the fixed vanes that Mr Merriman devised were producing a counter thrust to make it not apparent at all and to function like any other rc submarine. Infact it was interesting to read from Mr Merriman that the manta fins were infact required to make the Seaview funtion properly with the cadillac fins!

The DeBoer SEAVIEW cruising along at 'periscope depth'. I've already installed the pitch vanes in the nozzles to correct for the boats natural tendency to 'dive' while moving ahead submerged. Now, when the ballast tank is flooded and the boat settles into submerged cruising, it does so with little operator input from the transmitter. The submarine is surprisingly responsive to sailplane deflection as I work at the transmitter to change or hold depth. ven at a 'flank' bell the SEAVIEW holds pitch angle well, and it does that near the surface too, where other submarines become a bit more temperamental.

The significant maneuverability problems with this boat occur as a consequence of a turn while submerged. Sea-trails taught me to 'ease' the SEAVIEW into high speed submerged turns. To put the rudder hard over while running at any significant speed rolls the boat into an uncontrollable dive to the bottom. (American LOS ANGELES class attack submarines have the same problem). Other than that, and the SEAVIEW's woefully poor backing down ability, it handles pretty much like any other r/c submarine.

Speaking of thrust from the bow and turning radius vs pitch, what about bow thrusters?

There appears to be enough room inside a Teskey Seaview for bow thruster. Is there enough room for a small bow thruster in the Moebius Seaview? Not that I would go that route, just asking based on your skill and knowledge.