Selective Flow-Blocking Blade Assembly for Stable Wind Ship Propulsion
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Solution Overview
Problem
Existing wind-assisted ship propulsion systems face challenges in efficiently adapting to varying wind directions from both starboard and port sides, leading to unstable flow patterns, vibration, and resonance, which affect propulsion efficiency.
Innovation Solution
A blade assembly with aerofoil assemblies arranged on either side of a central plane, featuring overlapping aerofoils and a flow blocking arrangement that can be shifted to optimize airflow through one set of aerofoils while limiting airflow through the other, using a movable wing element and stationary barrier to stabilize airflow and reduce separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a blade assembly uses both first and second aerofoil assemblies simultaneously for starboard and port side wind, then the system can adapt to various wind directions, but unstable flow patterns occur causing vibration and resonance
Solution Approach 1:
The patent implements a flow blocking arrangement that is selectively shiftable between different positions to dynamically control which aerofoil assembly is active. This dynamic configuration allows the system to adapt to varying wind directions while maintaining stable flow through the selected aerofoil assembly, preventing vibration and resonance issues that would occur with simultaneous operation of both assemblies.
Solution Approach 2:
The blade assembly is divided into separate first and second aerofoil assemblies, each dedicated to specific wind directions (starboard or port side). The flow blocking arrangement selectively activates one assembly at a time, segmenting the airflow path to ensure stable, laminar flow through the active assembly while blocking the other, thereby preventing unstable flow patterns and resonance.
2Adaptability or versatility
If air flows through both first and second aerofoil assemblies, then the blade assembly can handle wind from any direction, but losses occur due to unstable flow patterns and vibration
Solution Approach 1:
The flow blocking arrangement is dynamically positioned to block airflow through the inactive aerofoil assembly while allowing optimal flow through the active assembly. This dynamic control prevents energy losses from unstable flow patterns and vibration, maximizing propulsion efficiency while maintaining the ability to handle wind from any direction by selecting the appropriate assembly.
Solution Approach 2:
The flow blocking arrangement converts what would be harmful unstable flow patterns and vibration into beneficial stable flow conditions by selectively blocking one aerofoil assembly. This transforms the potential harm of having dual assemblies into a benefit by using the blocking mechanism to ensure only one assembly operates at a time, eliminating energy losses while preserving directional adaptability.
3Stability of the object's composition
If the blade assembly is designed with symmetrical aerofoil assemblies for both starboard and port side, then structural balance is achieved, but boundary layer separation risk increases
Solution Approach 1:
The flow blocking arrangement dynamically controls airflow to pass through only one aerofoil assembly at a time, ensuring that the boundary layer remains attached to the suction side of the active assembly. This dynamic flow control prevents boundary layer separation and maintains reliable aerodynamic performance, while the symmetrical design of both assemblies preserves structural balance when the blocking arrangement is in neutral or retracted position.
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 enhances propulsion efficiency by stabilizing airflow, reducing vibration, and minimizing losses due to unstable flow patterns, allowing for optimal adjustment to wind direction, thereby improving the ship's propulsion performance.
Implementation Method 1
a first aerofoil assembly and a second aerofoil assembly, each of the first aerofoil assembly and the second aerofoil assembly comprising at least two aerofoils
Implementation Method 2
directing air coming in through the inlet gap between the aerofoil assemblies out into the boundary layer of the aerofoil assembly in action
Implementation Method 3
reducing the risk of separation of the boundary layer of the suction side
Data Source
Figure 1
Figure 2a~2b
Figure 3~5
AI summary
Herein is disclosed a blade assembly (1) for providing wind propulsion for a ship (2), as well as such ship (2) having one or more blade assemblies (2), the blade assembly (1) comprising a top end part and a lower end part for being coupled to a part of the ship (2), and a first and a second aerofoil assembly (3, 4), each of the and the second aerofoil assembly (3, 4) comprising at least two aerofoils (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c'), wherein the first aerofoil assembly (3) is arranged at one side of a central plane (CP) of the blade assembly (1) and the second aerofoil assembly (4) is arranged at the opposite side of the central plane (CP) than the first aerofoil assembly (3), wherein the at least two aerofoils (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c') of each of the first and the second aerofoil assembly (3, 4) are oriented with a leading edge (LE) of the aerofoil (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c') towards an inlet gap (IG) of the blade assembly (1) between the first aerofoil assembly (3) and the second aerofoil assembly (4), wherein the at least two aerofoils (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c') of each of the first and the second aerofoil assembly (3, 4) are arranged in an overlapping sequence so that one or more flow channels (FC) are formed between neighbouring aerofoils (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c'), and wherein for each of the first and the second aerofoil assembly (3, 4) an assembly camber line (ACAL) connecting the leading edge (LE) of the front aerofoil (5a, 5a', 105a, 105a') nearest the inlet gap (IG) with the trailing edges (TE) of each of the aerofoils (5a, 5a', 5b, 5b', 5c, 5c', 105a, 105a', 105b, 105b', 105c, 105c') in the aerofoil assembly (3, 4) from the front aerofoil (5a, 5a', 105a, 105a') towards the back aerofoil (5b, 5b', 105b, 105b') nearest an outlet gap (OG) of the blade assembly (1) deviates from an assembly chord line (ACHL) connecting the leading edge (LE) of the front aerofoil (5a, 5a', 105a, 105a') with the trailing edge (TE) of the back aerofoil (5b, 5b', 105b, 105b') in a direction with a component away from the central plane (CP), the blade assembly (1) further comprising a flow blocking arrangement (10, 11, 13, 14) which can be selectively shifted between a first position, where flow of air from the inlet gap (IG) and out through the flow channel(s) (FC) of the first aerofoil assembly (3) is limited, and a second position, where flow of air from the inlet gap (IG) and out through the flow channel(s) (FC) of the second aerofoil assembly (4) is limited.