Exterior Structure Design Alternatives Cornell CUAV: Twin hull on aluminum frame designMIT Orca 4:...

Exterior Structure Design Alternatives

Cornell CUAV: Twin hull on aluminum frame design MIT Orca 4: Dual side thrusters

Colorado HydroBuff R5L: Front dive planes and aft rudder Florida Atlantic Squid: Vector thrust control

Hydrodynamics Mechanical Design

• Myring Hull Contour – Design developed by U.S. Navy to

minimize drag for submersible objects.– Divides into 3 compartments: Nosecone,

mid-section and tailpiece• Dimensions

– Nose Cone Length: 6 inches– Mid Section Length: 24 inches– Tailpiece Length: 12 inches– Mid Section Thickness: 1/8 in.– Maximum Outer Diameter: 6 inches

• Material Selection– Nose Cone: PVC– Mid Section: Aluminum 6061– Tailpiece: Aluminum 6061

• Control Surface Configuration– 4 NACA 0012 airfoils mounted to the front

of the tailpiece

Total Drag computed to be 16.1 N at 5 Total Drag computed to be 16.1 N at 5 knots (with antenna deployed at 6 in.)knots (with antenna deployed at 6 in.)

Control Surface Sealing Design

• Must withstand pressure of 45.0 psi• Dynamic Seals

– American Variseal W10-MS-R-010-W-Z80 Rod Seal

– Low Friction Servo Movement– Spring Loaded Rotary Shaft Seals

• Dimensions– 0.375 in.Housing Groove Diameter – 0.99 in. Gland length

• Seal pressed in housing groove in tailsection

• Servo used for electronic control of control surfaces

• 1/4 in. diameter stainless steel shaft passes from servo to control surface

– Aluminum coupler and set screws used to attach servo to shaft

– Pins used to attach shaft to control surface

Control Surface Sealing Design

Rotary seal schematic as provided by American Veriseal