So Im working on a interesting concept AUV/ROV that is meant for long range endurance trips trying to be as energy efficient as possible. In order to do this, the pressure hull made of 4" PVC will be enclosed in a fiberglass outer hull with an ideal hydrodynamic shape using a quarter length elliptical nose, and tapered hull seven times as long as the width. This configuration is supposed to be most quiet and least drag inducing.
Included is a rough illustration (I need to scan my paper drawings, this is just MS paint) showing a general layout, the blue rectangle is space available for a 4" pressure hull inside the general hull shape.
At the rear is a ducted propeller I plan to make out of 6" PVC with a slip coupler glued inside to create a .5" thick ring that I intend to sand down like a kort nozzle. The circle indicates a swivel, without giving an elaborate explanation imagine the rear portion behind the ball and including the nozzle is directional giving vectored thrust.
The intersecting red lines indicate the largest part of the outer hull and the only cylindrical portion of the hull that is not curved or tapered. I planned to try and put the center of gravity at or near that point.
In order to reduce turbulence, I wanted to have the dive planes at the straitest part of the hull (where the red lines cross) but I am concerned that having the control surfaces in line with the center of gravity I will be losing allot of control since the COG wont be serving as a pivot for an outer torque exerted by the planes if they were forward in the nose more, or higher in a sail. What effect do any of you think it would have to have dive planes aligned with the COG?
Additionally I need some help sourcing a 5" propeller blade and matching it to a motor, guidance would be helpful. I am under the impression that a larger prop at lower rpms is the most efficient.
Im gradually putting together more drawings and I will put them up as I finish. I appreciate your feedback
