Abstract: An undersea vehicle having both low emitted noise and low reflectivity is provided. The undersea vehicle has a hollow cylindrical hull with all components, sensors, electronics, motors, and other internal components with the exception of the propellers, located within the shell of the cylindrical hull. The hollow center of the hull provides a duct and propeller configuration with the shaping of the inlet tube designed to reduce forward noise transmissions, such as reflected active sonar signals and emitted noise. The internal duct gradually constricts to a throat section and thereafter diverges to an output section where dual counter-rotating propellers are located. The result is that most of the internal turbulent flow and the propeller noise is located behind the throat and is thereby reflected in the aft direction. Steering of the vehicle is accomplished by canting the leading edge intake section and the duct exhaust section.

Abstract: Disclosed is a device used to maneuver a vehicle consisting of a tubular y with suction circumferential slots adjacent its forward end and exhaust circumferential slots adjacent its aft end on both the outer and inner peripheral surfaces. Fluid is conveyed between the forward slots on one surface of the tubular body to the aft slots on the other surface of the body to produce asymmetrical pressure on the tubular body while traveling through a fluid medium.