Turbine Blade Leading-Edge Inclination for Radial-Inlet Flow Separation
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Solution Overview
Problem
In turbines where gas flows into the turbine blade wheel from a radially outer side, separation of the gas flow can occur at the inlet portion, leading to decreased efficiency due to vortex generation.
Innovation Solution
The turbine blade wheel incorporates blades with leading edges inclined opposite to the rotation direction, with an inclination angle between 0° and 45°, optimally within 10° to 30°, to mitigate gas flow separation and vortex formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gas flows into the turbine blade wheel from a radially outer side, then the turbine structure is simplified and gas flow path is established, but gas flow separation occurs at the inlet portion causing vortex generation and efficiency decrease
Solution Approach 1:
The leading edge of the blade is given a specific inclination (0° < α ≤ 45°) that differs from other parts of the blade. This local geometric modification at the leading edge specifically addresses the gas flow separation problem at the inlet portion without changing the overall turbine structure, thereby maintaining manufacturing simplicity while improving turbine efficiency
Solution Approach 2:
Instead of trying to straighten the gas flow path or modify the inlet geometry to accommodate radial flow, the invention inverts the approach by inclining the leading edge opposite to the rotation direction. This counterintuitive design compensates for the adverse effects of radial inflow and prevents flow separation, resolving the contradiction between structural simplicity and efficiency
2Loss of energy
If the leading edge is inclined opposite to the rotation direction with an inclination angle greater than 0° and less than or equal to 45°, then gas flow separation is suppressed and vortex generation is reduced, but blade geometry becomes more complex
Solution Approach 1:
Only the leading edge portion of the blade is inclined at an angle α, while the rest of the blade geometry can remain relatively simple. This localized geometric feature achieves the dual benefit of suppressing flow separation and maintaining manufacturing feasibility, thus improving turbine efficiency without excessive complexity
Solution Approach 2:
The inclination angle α is optimized within a specific range (0° < α ≤ 45°) to achieve the best balance between preventing flow separation and maintaining geometric simplicity. This parameter optimization ensures that the blade geometry remains manufacturable while effectively improving turbine 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
This design enhances turbine efficiency by suppressing gas flow separation and vortex generation, particularly in variable capacity turbines.
Implementation Method 1
separation of the gas flow may occur, and a vortex may be generated
Data Source
AI summary
A turbine includes: a turbine scroll flow path; a turbine blade wheel disposed on a radially inner side with respect to the turbine scroll flow path; and a blade included in the turbine blade wheel, the blade having a leading edge inclined to a side opposite to a rotation direction side of the turbine blade wheel as the leading edge extends from a hub side to a shroud side, the leading edge having an inclination angle greater than 0° and less than or equal to 45° with respect to an axial direction of the turbine blade wheel as viewed in the radial direction.