A novel watercraft propulsion device is disclosed that includes multiple propulsive elements improving power and efficiency over prior designs. A self-adjusting variable pitch propeller is combined with a water jet and an exhaust driven turbine to provide optimal thrust and efficiency across the range of engine power, load and watercraft speed. Propulsive elements are axially disposed around a central drive shaft and exhaust port with the combined water jet/exhaust turbine disposed closest to drive shaft and the variable pitch propeller attached to the exterior of the water jet housing. A rotating duct is fixed to the propeller blades and rotates with the blades to reduce cavitation. Combined apparatus provides increased performance and efficiency over all watercraft speeds/load as well as additional safety due to the ducted propeller. Propulsor with an inducer, conical impeller and a diffuser also shown.

In response to a torque that is applied to a clutch module not exceeding a torque threshold, the clutch module is locked where a blade is configured to be at a first pitch angle in response to the clutch module being locked. In response to the torque that is applied to the clutch module exceeding the torque threshold, the clutch module is released where the blade has a range of motion which extends from the first pitch angle to a second pitch angle in response to the clutch module being released.

The present disclosure relates to a method (1) and an apparatus (10) for adjusting flow properties of a propeller (103) of a propulsion system (100) for watercrafts (1000), in particular for boats and ships, depending on the operation state, comprising the steps of determining the operation state (2) of the propulsion system (100), wherein in the propulsion system (100) either a thrust state or a generator state, in particular a hydrogeneration state for generating energy by hydrogeneration, is present, and adjusting the flow properties (3) of the propeller (103) based on the determined operation state.

A method controlling a thruster of a marine vehicle is provided. The marine vehicle is at least partially submerged in a liquid and includes a body and a thruster including two propellers. Each propeller includes blades intended to tum about a rotation axis of said propeller. The method includes a step of low-speed maneuver controlling, during which the thruster is controlled in such a way that each propeller generates a flow directed toward the flow generated by the other propeller and reaching the flow generated by the other propeller.

A method for controlling a thruster of a marine vehicle includes a body and a thruster mounted on the body of the vehicle, the vehicle being at least partially immersed in a liquid and moving with respect to the liquid along an axis of displacement in a direction of displacement and rotating about at least one axis of rotation perpendicular to the axis of displacement with a rotational speed, the thruster including an upstream propeller and a downstream propeller along the axis of displacement in the direction of displacement. The method including a stabilization step, in which the thruster is controlled such that the main axis of the upstream flow generated by the upstream propeller at a given instant t is an estimated main axis on which a position of a center of the downstream propeller, situated substantially on the axis of rotation of the downstream propeller, is estimated to be situated at a later instant t+dt at which the flow generated by the upstream propeller at the given instant t reaches the downstream propeller, the estimated main axis depending on the rotational speed of the vehicle.

A bistable pitch propeller includes a ball, a spring, and a clutch module where the clutch module has a range of rotational movement between a locked end position and a released end position. The clutch module includes a detent, where the ball sits inside and outside of the detent when the clutch module is in the locked end position and released end position, respectively. In response to an input torque and a spring force from the spring, the clutch module rotates toward the released end position and the locked end position, respectively. The bistable pitch propeller also includes an aircraft blade where the aircraft blade is at the first pitch angle and the second pitch angle when the clutch module is in the locked end position and the released end position, respectively.

A device includes a hub and a blade. The hub has a cylindrical geometry. The blade extends radially from the hub. The blade has a helical structure. The blade includes a leading edge, a winglet, a trailing edge, and a trough. The leading edge is formed on the blade and has an arcuate geometry. The winglet of the blade is distal relative to the hub. The winglet angles away from a surface of the blade. The trailing edge is formed on the blade to be opposite the leading edge. At least a portion of the trailing edge forms a pitch-line cup that is angled with respect to the surface of the blade. The trough is formed in a transition between the pitch-line cup of the trailing edge and the winglet. The trough forms a recess that is relatively closer to the surface of the blade.

A method for controlling a thruster of a marine vehicle includes a body and a thruster mounted on the body of the vehicle, the vehicle being at least partially immersed in a liquid and moving with respect to the liquid along an axis of displacement in a direction of displacement and rotating about at least one axis of rotation perpendicular to the axis of displacement with a rotational speed, the thruster including an upstream propeller and a downstream propeller along the axis of displacement in the direction of displacement. The method including a stabilization step, in which the thruster is controlled such that the main axis of the upstream flow generated by the upstream propeller at a given instant t is an estimated main axis on which a position of a center of the downstream propeller, situated substantially on the axis of rotation of the downstream propeller, is estimated to be situated at a later instant t+dt at which the flow generated by the upstream propeller at the given instant t reaches the downstream propeller, the estimated main axis depending on the rotational speed of the vehicle.

A method controlling a thruster of a marine vehicle at least partially submerged in a liquid includes a body and a thruster including two propellers, each propeller including blades intended to turn about a rotation axis of said propeller, the method including a step of low-speed maneuver controlling, during which the thruster is controlled in such a way that each propeller generates a flow directed toward the flow generated by the other propeller and reaching the flow generated by the other propeller.

A method for controlling a propulsion system of a marine vehicle is disclosed. A controller forms data on pitch angles of at least two foils, which are in a rotatable manner attached with a foil wheel, based on at least an angularly variable eccentricity of the at least two foils and an angle of rotation of the foil wheel. The variable eccentricity is limited at a portion of the angle of rotation of the foil wheel. An actuator arrangement receives the data from the controller and sets the at least two foils at the pitch angles based on the data.