Waterjet Vessel Control via Trim Deflector Angles
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Solution Overview
Problem
Waterjet-driven marine vessels lack the ability to counter outside yawing disturbances without slowing down or placing appendages in the water, and they cannot develop downward trimming forces at the transom, leading to instability and increased risk of "stuffing" during certain sea and weather conditions.
Innovation Solution
A control system that individually controls the angles of deflection of waterjet nozzles and trim deflectors to apply net yawing, rolling, and trimming forces independently, without inducing unwanted motions, by maintaining steering nozzles in a neutral position and actuating trim deflectors to create directional stability and trimming forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If waterjet-driven vessels use conventional propulsion systems with propellers and rudders, then they can counter yawing disturbances and maintain directional stability, but they experience increased drag and reduced speed
Solution Approach 1:
The patent segments the waterjet flow into multiple discrete jets that can be independently controlled. By selectively activating and directing individual jets, the system can generate yawing moments and trimming forces without requiring conventional appendages like rudders or stabilizers, thus maintaining high speed while achieving directional stability
Solution Approach 2:
The patent introduces software control systems and flow distribution mechanisms as intermediaries between the engine and waterjet nozzles. These intermediaries enable precise control of jet direction and activation, allowing the system to generate stabilizing forces through intelligent flow management rather than mechanical appendages
2Stability of the object's composition
If waterjet-driven vessels place appendages in the water to counter yawing disturbances, then they can maintain directional stability, but they experience increased drag and reduced operational efficiency
Solution Approach 1:
The patent extracts the stabilizing function from conventional water-based appendages and relocates it to the waterjet propulsion system itself. By using the propulsion jets to generate stabilizing forces, the system eliminates the need for separate stabilizing appendages that would create drag and energy loss
Solution Approach 2:
The patent makes the waterjet propulsion system multi-functional by enabling it to perform both propulsion and stabilization functions. The same jets that provide forward thrust can be directed to generate yawing moments and trimming forces, eliminating the need for dedicated stabilizing appendages
3Reliability
If waterjet-driven vessels cannot develop downward trimming forces at the transom, then they maintain simple propulsion systems, but they experience increased risk of stuffing and reduced safety in certain sea conditions
Solution Approach 1:
The patent introduces dynamic control of waterjet deflection angles and activation patterns to generate downward trimming forces. By dynamically adjusting jet direction and flow distribution, the system can create variable trimming forces that adapt to different sea conditions without requiring fixed mechanical trimming appendages
Solution Approach 2:
The patent changes the operational parameters of the waterjet system by enabling independent control of jet deflection angles and flow rates. This allows the system to generate downward forces at the transom by directing jets appropriately, providing trimming capability through parameter adjustment rather than additional mechanical components
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This system enhances directional stability, allows for downward trimming forces at the transom, and mitigates yawing disturbances without slowing the vessel, improving operational efficiency and safety in various sea conditions.
Implementation Method 1
Other marine vessel propulsion systems utilize water jet propulsion to achieve similar results. Such devices include a pump, a water intake or suction port and an exit or discharge port, which generate a water jet stream that propels the marine vessel.
Implementation Method 2
A control system that individually controls the angles of deflection of waterjet nozzles and trim deflectors to apply net yawing, rolling, and trimming forces independently
Implementation Method 3
The water jet stream may be deflected using a 'deflector' to provide marine vessel control by redirecting some water jet stream thrust in a suitable direction
Data Source
AI summary
A method for controlling a marine vessel having first and second steering nozzles and first and second trim deflectors comprises generating at least a first set of actuator control signals and a second set of actuator control signals. The first set of actuator control signals is coupled to and controls the first and second steering nozzles, and the second set of actuator control signals is coupled to and controls the first and second trim deflectors. The acts of generating and coupling the first set of actuator control signals and the second set of actuator control signals result in inducing any of a net yawing force, a net rolling force, and a net trimming force to the marine vessel without inducing any other substantial forces to the marine vessel by controlling the first and second steering nozzles and the first and second trim deflectors. Also disclosed is a system for controlling a marine vessel.