Vertical-Axis Water Turbine for Marine Propeller Wake Recovery
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Solution Overview
Problem
Current energy recovery systems for marine vessels face challenges in efficiently harnessing dissipated rotational power from propeller wakes due to space constraints, accessibility issues, and interference with rudder steering, leading to reduced efficiency and increased drag.
Innovation Solution
An energy recovery system featuring a vertically axis water turbine positioned off-center and aft of the propeller, within the wake range, to capture the axial velocity of the vortical flow, minimizing interference with the rudder and propeller while maintaining accessibility and reducing drag.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydro-generator is placed deeper below the water surface to avoid wake interference, then the performance is improved, but the lever arm length increases causing greater force on mountings and increased drag
Solution Approach 1:
The patent transitions from horizontal placement (transom-mounted) to vertical placement (under the hull), changing the spatial dimension. This allows the hydro-generator to be positioned deeper below the water surface while maintaining a compact vertical structure that reduces the lever arm length compared to horizontal extensions, thereby reducing force on mountings and drag.
2Power
If the propeller size is increased to generate more power, then the power output is improved, but the drag increases causing loss of vessel speed
Solution Approach 1:
The patent converts the harmful wake and vortical flow (which represent energy loss) into a beneficial resource by positioning the vertical hydro-generator to harness these flows for power generation. This allows the system to recover energy that would otherwise be wasted, effectively increasing power output without requiring a larger propeller that would increase drag.
3Ease of repair
If a transom-mounted hydro-generator is used for easier maintenance, then the ease of repair is improved, but the system becomes bulky and aesthetically unpleasant when lifted
Solution Approach 1:
The patent employs vertical placement under the hull rather than horizontal transom mounting. This dimensional change creates a compact configuration that minimizes the volume occupied by the hydro-generator system when lifted, eliminating the bulky appearance while still maintaining accessibility for maintenance through the vertical arrangement.
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 configuration enhances power generation efficiency, reduces the risk of jamming and damage, and maintains steering efficiency, offering a compact and low-drag solution for energy recovery.
Implementation Method 1
at least one water turbine with vertical axis, rotatably fixed to a vessel hull and respectively arranged aft and off center... in order to recover at least part of the dissipated rotational power from the accelerated vortical water flow
Data Source
AI summary
An energy recovery system 100 for a marine vessel 200 is herein disclosed comprising at least one water turbine 101, 102 with vertical axis 105, 106 respectively arranged aft and off center, that is either port side or starboard side, with respect to a rotational axis 211 of a respective propeller but at a distance from the propeller and from the rotational axis of the propeller such as to be at least partially in a wake range 21′ of the propeller in order to recover at least part of the dissipated rotational power. A vessel 200 comprising at least one energy recovery system 100 and a method for recovering at least part of the energy dissipated by the marine vessel are herein also disclosed.