Fan Blade Root Through Holes for Weight Reduction
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Solution Overview
Problem
There is a need for further weight reduction in gas turbine engine fan blades while maintaining structural strength, as existing hollow cavity designs do not adequately address the requirement for lightweight yet robust components.
Innovation Solution
The design incorporates through holes extending from the root to cavities in the fan blade, which are plugged at the inner face of the root to prevent condensation migration, and optionally covered with a fiber-resin composite or fluoroelastomer material, enhancing structural integrity and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If hollow cavities are included in the fan blade to reduce weight, then weight reduction is achieved, but structural strength may be compromised
Solution Approach 1:
The patent implements through-holes that extend from the root cavity into the internal cavities of the fan blade, creating a nested structure where the through-hole system is positioned within the larger cavity system. This nested configuration allows condensation to be channeled through the through-holes to drainage outlets while maintaining the weight-saving cavity structure, thus resolving the contradiction between weight reduction and structural integrity.
Solution Approach 2:
The through-holes serve as intermediary structures that connect the root cavity to the internal cavities and provide a controlled pathway for condensation drainage. These intermediary elements enable the hollow cavity structure to maintain both its weight-reduction function and its structural strength by providing designated drainage paths that prevent condensation accumulation within the cavities.
2Object-affected harmful factors
If through-holes are added to enable condensation drainage, then condensation migration is prevented, but device complexity increases
Solution Approach 1:
The through-holes are designed to serve multiple functions simultaneously: they provide structural support as integral parts of the fan blade, enable condensation drainage from cavities to outlets, and maintain aerodynamic surface continuity. This multi-functionality reduces the need for separate drainage components, thereby preventing condensation migration without proportionally increasing device complexity.
Solution Approach 2:
The drainage function is merged with the structural geometry of the fan blade itself. The through-holes are integrated directly into the blade's internal structure rather than being separate attached components, and the drainage outlets are positioned to utilize existing structural features. This merging approach enables effective condensation drainage while minimizing additional complexity.
Data Source
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AI summary
A lightweight fan blade for use in turbofan gas turbine engines is disclosed. The fan blade includes a metallic airfoil connected to a root. The airfoil has a pressure side and a suction side. The suction side of the airfoil includes one or more cavities for weight reduction purposes. A cover is attached to the suction side of the body to cover or enclose the one or more cavities. In addition to the one or more cavities, through holes are formed from the inner face of the root into one or more of the cavities for further weight reduction. The through holes may be covered by a spacer and one or more through holes may be extended from the inner face of the root into each of the cavities.