USA As Represented by Secretary of the Navy

Charles M Dai

Carl W Baumann

Young T Shen

Frank B Peterson

Carol L Tseng

Phuc N Nguyen

Christopher J Kerr

John L Allison

John F McMahon

Bruce D Cox

Han-Ch'ing Wang

The present invention's methodology for designing a fluid propulsion intake configuration of a marine vessel considers the integral geometry of the inlet together with a portion of the hull, with respect to which the inlet's entrance opening is flush. The inventive methodology typically includes definition of an inlet reference line (an 'axial' description, straight and/or curved, of the inlet), cross-planes (each of which perpendicularly intersects the inlet reference line), a footprint (a planar outline of the inlet's entrance opening), an inlet shaping line (a projection of the footprint onto the hull portion), inlet flow lines (angularly spaced about the circumference of the inlet shaping line, each connecting the cross-planes), two fairing reference curves (one at the inlet's entrance opening and the other on the hull portion, thereby demarcating a fairing therebetween that is consistent with the inlet flow lines), and a lip nose (at the inlet's entrance opening).

Design of a flush inlet as integrated with a ship hull for waterjet propulsion

The stern end of a seawater hull has a rotor hub with propeller blades thereon. The rotor hub is rotated for propulsion of the hull by means of a propeller shaft extending through a sealed compartment within the hull. Such sealed compartment and an electrically powered control system is disposed within the hull to automatically adjust angular deflection of deformable tip portions of the propeller blades by means of blade embedded actuators, in response to varying input signals which respectively reflect changes in seawater conditions such as temperature and strain imposed on the propeller blades during propelling rotation of the rotor hub.

Propellor blade adjustment system for propulsion through fluid environments under changing conditions

The stern hull portion of a sea craft through which main exit flow channels extend to projecting jet propulsion nozzles, is provided with facilities for controlled maneuvering of the sea craft, including steering, stopping, negative thrust backing and docking without substantial hydrodynamic loading and with facilitated installation. Such maneuvering control facilities include a secondary flow channel extending from each of the main exit flow channels having two angularly related subchannel branches for pressurized water outflow through gated openings in the hull from which propulsion jets emerge under maneuvering control. Either control of a subchannel diverting flapper, or by use of selective closure gates and a flow diverting flap within the main exit flow channel, maneuvering may be effected in response to inflow through inlet openings in the hull of water that is pressurized before supply to the main exit flow channels.

Maneuvering of submerged waterjet propelled sea craft

Waterjet flow emerging from a jet propulsor body through a cross-sectionally circular duct is conducted through a cross-sectionally rectangular duct passage extending through transition and exhaust aft sections attached to and angularly adjusted relative thereto. Under selective maneuver controls within the propulsor body, the transition section is angularly adjusted relative to the body while pivotal vanes and flaps on the exhaust section are angularly adjusted to direct exit outflow through the exhaust section for steering and reversing purposes.

Steering and directional reversing control for waterjet propulsion

An elongated fluid dynamic water jet type of propulsion body receives an inflow of fluid through inlet openings for entry into a jet propulsor from which an outlet jet emerges for passage through an internal transition passage to an exit end between two pairs of horizontal flaps hinged to the body at the exit end for angular displacement about parallel spaced horizontal axes from horizontal neutral positions. Four pair of flaps are pivotally mounted within the transition passage for angular displacement about parallel spaced vertical axes from neutral positions. Actuators inside of the propulsion body connected to the flaps are selectively controlled to impart in-phase angular displacement to all of the flaps about their horizontal and vertical axes from the neutral positions for directional steering by angular deflection of the jet exit outflow from the exit end of the body. To reverse propulsion, only the actuators for the horizontal flaps are activated in an out-of-phase mode to effect angular displacement of each pair of the horizontal flaps in opposite directions into engagement with each other thereby blocking jet outflow from the exit end of the body causing a directional reversal of the propulsion jet by outflow from openings formed in the body rearwardly of the exit end.

Directional steering controlled jet propulsion

A waterjet propulsion system for a vessel permits stationary mounting of the pump within the vessel hull, and further allows minimizing the size and weight of the pump casing, by providing a pivotably moveable, hull mounted and supported, steering and reversing sleeve mechanism positioned to receive the waterjet flow from a waterjet nozzle and to redirect at least a portion of that flow for steering and production of reverse thrust. The sleeve structure also permits all machinery for achieving control of steering and reverse thrust to be placed in protected locations such as being faired into the sleeve or within the vessel hull. Protection of linkages and reduction of the weight thereof is also provided.

Hull supported steering and reversing gear for large waterjets

The invention is directed to an improved water jet propulsion system for a marine vehicle. The water jet propulsion system of the present invention incorporates an unconventional and compact design including a short, steep, hydrodynamically designed inlet duct adapted for mounting to the surface of the vehicle hull and extending internally thereof, a water jet pump having an inlet end attached to the outlet end of the inlet duct, a motor for rotating the pump impeller, a drive shaft located completely outside of the flow path connecting the motor with the pump impeller, a flow passage for discharging accelerated flow received from the pump in a generally rearward direction, and a steering and reversing mechanism pivotably mounted about a substantially vertical axis to the aft portion of the vehicle hull for redirect accelerated flow received from the outlet nozzle so as to provide maneuvering capability to the vehicle.

Compact water jet propulsion system for a marine vehicle

The invention is directed to a method for designing a fluid inlet duct for marine vehicle hull, generally comprises the steps of: (a) determining an inlet duct surface geometry, represented by a series of fifth-order Bezier cross-link curves, within specified hydrodynamic design constraints; (b)generating a panel representation of the surface geometry; (c) calculating the pressure and velocity distributions of the flow within the inlet duct; (d) evaluating the surface geometry; (e) repeating steps (a)-(d) for subsequent iterations of the surface geometry until the specified hydrodynamic design constraints are satisfactorily met at a predetermined design condition; (f) evaluating a resulting surface geometry at off-design conditions; (g) repeating step (a)-(d) for subsequent iterations of the surface geometry until the specified hydrodynamic design constraints are satisfactorily met at off-design conditions; (h) performing a geometric refinement to a fillet region of high curvature in the inlet duct; (i) generating a panel representation of a resulting surface geometry; (j) calculating the pressure and velocity distributions of the flow within the inlet duct; (k) evaluating the surface geometry at desired operating conditions; and (l) repeating steps (h)-(k) for subsequent iterations of the surface geometry until the specified hydrodynamic design constraints are optimally met.

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Potomac, MD, United States of America

Charles M Dai