Fuel Cell Air Injection Under Hull for Lower Hydrodynamic Drag
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Solution Overview
Problem
Existing devices for reducing hydrodynamic drag in vessels are inefficient due to the energy consumption of compressors and increased mass, which limits their energy efficiency, especially when operating in strong swells or waves, and they do not effectively utilize the by-products of fuel cell operation.
Innovation Solution
A device that uses a fuel cell to generate electrical energy and reuses the discharged air to inject air bubbles under the hull, eliminating the need for a compressor and enhancing energy efficiency by reducing the vessel's mass and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a compressor is used to provide pressurized air for forming an air cushion under the vessel hull, then the air cushion can be maintained to reduce hydrodynamic drag, but the energy consumption increases and the vessel mass increases
Solution Approach 1:
The invention converts the harmful waste heat and discharged air from the fuel cell into beneficial resources. The discharged air, which would otherwise be released into the atmosphere, is captured and pressurized using waste heat from the fuel cell to form an air cushion under the hull, reducing hydrodynamic drag. This transforms waste products into useful resources for drag reduction.
Solution Approach 2:
The invention merges the fuel cell system with the drag reduction system by integrating the air cushion formation process with the fuel cell's exhaust air utilization. The fuel cell's discharged air is directly used as the source gas for the air cushion, combining two previously separate functions (power generation and drag reduction) into a unified system that shares resources.
2Object-affected harmful factors
If a compressor is used to inject air under the hull to reduce hydrodynamic drag, then the drag force decreases, but the vessel mass increases
Solution Approach 1:
The invention converts the harmful waste heat and discharged air from the fuel cell into beneficial resources. The discharged air, which would otherwise be released into the atmosphere, is captured and pressurized using waste heat from the fuel cell to form an air cushion under the hull, reducing hydrodynamic drag. This transforms waste products into useful resources for drag reduction.
Solution Approach 2:
The fuel cell system serves multiple functions: it generates electrical energy for propulsion and simultaneously provides pressurized air for the air cushion system that reduces hydrodynamic drag. This multi-functionality eliminates the need for separate compressors and reduces overall vessel mass.
3Object-affected harmful factors
If a static layer of air is used to cover the hull surface, then frictional forces from water are reduced, but the air cushion is broken by strong waves
Solution Approach 1:
The invention transitions from a static air cushion to a dynamic one by continuously injecting pressurized air from the fuel cell discharge into the air cushion zone. This dynamic replenishment allows the air cushion to maintain its integrity and effectiveness even under strong wave conditions, as the pressurized air continuously replaces any air that escapes or is disrupted by waves.
Solution Approach 2:
The invention changes the pressure parameter of the air cushion by using pressurized air from the fuel cell discharge instead of ambient pressure air. This increased pressure makes the air cushion more resistant to wave disruption and maintains its effectiveness in rougher sea conditions.
4Object-affected harmful factors
If air is injected under the hull to reduce hydrodynamic drag, then energy efficiency decreases due to compressor operation, but drag reduction is achieved
Solution Approach 1:
The invention converts the harmful waste heat and discharged air from the fuel cell into beneficial resources. The discharged air, which would otherwise be released into the atmosphere, is captured and pressurized using waste heat from the fuel cell to form an air cushion under the hull, reducing hydrodynamic drag. This transforms waste products into useful resources for drag reduction.
Solution Approach 2:
The fuel cell system serves itself by using its own discharged air and waste heat to power the air cushion system. The waste heat from the fuel cell is used to pressurize the discharged air, creating a self-sufficient system that does not require external energy input or additional compressors, thereby maintaining high energy efficiency.
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
The solution significantly increases energy efficiency by avoiding compressor energy use and reducing vessel mass, while effectively reducing hydrodynamic drag through air injection, maintaining lift during vertical surface injection and creating a turbulent flow for enhanced drag reduction.
Implementation Method 1
a fuel cell uses the chemical reaction between dihydrogen supplied by a tank and dioxygen found in the ambient air to provide an amount of electrical energy
Implementation Method 2
the use of a static layer of air or a stream of air in contact with the hull of the vessel makes it possible to decrease the frictional forces exerted by water on the hull
Implementation Method 3
a means of conveyance of a first amount of air discharged by the fuel cell to at least the first means of injection
Data Source
AI summary
A device for reducing hydrodynamic drag of a vessel including a hull; a fuel cell, and a system of conveyance of a first amount of air discharged by the fuel cell to at least one system of injection included by the hull, the system of injection being configured to inject the first amount of air opposite a surface of the hull intended to be immersed.