Horizontal Axis Hydro Turbine with Offset Blades
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Solution Overview
Problem
Hydroelectric turbines with vertical axes face inefficiencies due to vortices, limited shallow water installation, bending moments, and high aeroelastic stresses, while horizontal axis turbines struggle with constant torque and adaptability to varying water depths and flow rates.
Innovation Solution
A hydroelectric turbine with a horizontal axis and aerodynamic blades, modular design, and angularly offset blades connected by arched septa, allowing immersion in shallow waters with reduced resistance and increased structural stiffness, and a support structure for adjustable depth and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the rotor assembly has a vertical axis, then the blades can be immersed in deep waters, but the turbine cannot be installed in shallow waters and suffers from bending moments due to flow speed variation with depth
Solution Approach 1:
The patent inverts the conventional vertical axis orientation to a horizontal axis orientation. This inversion allows the rotor assembly to be installed in shallow waters while maintaining structural integrity, as the horizontal orientation eliminates the bending moments caused by vertical flow speed gradients that affect vertical axis turbines.
Solution Approach 2:
The patent changes the orientation parameter of the rotor assembly from vertical to horizontal. This parameter change enables the turbine to operate effectively in shallow waters and allows for depth adjustment along the horizontal axis, thereby improving adaptability to different water depths without suffering from the bending moment problems of vertical axis designs.
2Device complexity
If the rotor assembly is constrained only at the upper end, then the structure is simpler, but the rotation axis inclines due to flow pressure, decreasing hydrodynamic efficiency
Solution Approach 1:
The patent introduces a counterbalancing constraint at the lower end of the rotor assembly to counteract the inclination caused by flow pressure on the upper end constraint. This dual-constraint system maintains the rotation axis perpendicular to the flow direction, preventing energy loss while adding minimal structural complexity.
3Strength
If dividing septa are used to connect rotor modules, then structural resistance increases, but the septa offer high resistance to water flow, worsening energy efficiency and causing aeroelastic phenomena
Solution Approach 1:
The patent replaces solid dividing septa with thin, flexible connecting structures that provide sufficient structural resistance to hold the rotor modules together while offering minimal resistance to water flow. These thin film-like connectors eliminate the energy efficiency problems and aeroelastic phenomena caused by bulky solid septa.
4Adaptability or versatility
If the turbine operates in shallow waters with horizontal axis, then installation flexibility increases, but maintaining constant perpendicular orientation to flow becomes challenging
Solution Approach 1:
The patent employs dynamic adjustment mechanisms that allow the rotor assembly to maintain perpendicular orientation to the flow direction despite variations in water depth and flow conditions. The horizontal axis configuration with adjustable depth positioning enables the system to adapt dynamically while maintaining optimal orientation.
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
Enhances energy efficiency, adaptability, and maintainability by maintaining a perpendicular rotation axis, reducing aeroelastic effects, and providing constant torque, while allowing operation in shallow waters and varying basin widths.
Implementation Method 1
the blades have an aerodynamic shape, and in particular a NACA profile, in order to provide a higher fluid dynamic efficiency to each blade
Implementation Method 2
A rotor assembly with horizontal axis (x), completely immersed in a water flow, is provided
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3A~3B
AI summary
A hydroelectric turbine (100) comprising a rotor assembly (110) having a rotation axis x and comprising a number m of modules (111) adjacent to each other and aligned to each other, each module (111) comprising a number n of blades (115) parallel to the rotation axis x and arranged about its rotation axis x with a predetermined angular range Θ, said rotor assembly (110) arranged to rotate, in use, about its rotation axis x when the blades (115) are immersed in a water flow. The hydroelectric turbine (100) also comprises a support structure (120) arranged to support the rotor (110) and an electric power generator operatively connected to the rotor assembly (110) and arranged to generate electric power by the rotation of the rotor assembly (110) about its rotation axis x. The blades (115) have, in cross- section, an aerodynamic profile, in order to increase the fluid dynamic efficiency when they are immersed in said water flow. Furthermore, the support structure (120) is configured to keep the rotation axis x, in use, in a position substantially orthogonal to the water flow. The hydroelectric turbine (100) is configured in such a way that the n-th blade (115') of a first rotor assembly (110') is arranged with a predetermined angular offset φ with respect to the respective n-th blade (115'') of a second rotor assembly (110'') next to the first rotor assembly (110').