Re: [PSUBS-MAILIST] Ducting

Frank,

I saw one design that ducted the water flow from the underside of the sub through a channel to twin thrusters at the rear just inside the fairing. The arrangement looked really neat, however the thrusters didn't articulate at all so all maneuvering was left to the rudders and dive planes. The ultimate seems to be Cliff's jet-drive which does articulate.

I'm trying to keep it as simple and clean as possible. Right now I'm expecting to have a single, fully articulated Kort thruster at the rear, but that could raise issues of torque roll. Hopefully the model process and the full-scale mockup (and the critiques) will help resolve that. I might end up going with dual thrusters.

By the way, are you going to update your profile?

Jim

In a message dated 11/20/2010 12:46:02 P.M. Central Standard Time, ShellyDalg@aol.com writes:

In a message dated 11/20/2010 10:37:23 A.M. Eastern Standard Time, JimToddPsub@aol.com writes:

eliminate the possibility of snagging on something as much as possible, and a Kort is part of that.

I imagine there is some loss of efficiency but I have seen a few thruster designs where the props and motors are enclosed inside a "fairing" and water flow is "ducted" to the props. This eliminates entanglement issues but again, probably would slow the boat a bit.

As an example, think of the props on the James Bond Car that was a submarine. It was a Lotus I think but the props were visible at the back end and water going TO the props went through a grille type plate below the vehicle.

That vehicle was actually built and was a working "wet ambient" sub where the pilot wore scuba gear. Of course, in the movie it was portrayed as a "dry 1 ATM. sub"

Still, it was an early inspiration to me.

Frank D.