Turbomachine Guide Vane Wheel Segmentation for Borescope Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The decreasing size of core engines in modern turbofan aircraft engines results in insufficient pitch spacing between guide vanes, making it difficult to accommodate borescopes for visual inspection and maintenance without disassembling the engine.
Innovation Solution
A guide vane wheel design with two segments of guide vanes, each with a constant cascade pitch, where the outermost vanes have increased circumferential distances from adjacent vanes, creating enlarged passages for borescope access, allowing for access even with smaller cascade pitches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the core engine size is reduced to increase bypass ratio, then fuel efficiency improves, but the pitch spacing between guide vanes becomes insufficient for borescope access
Solution Approach 1:
The guide vane wheel is divided into two distinct segments: a first segment with guide vanes having a first pitch spacing, and a second segment with guide vanes having a second pitch spacing. This segmentation allows different regions of the same wheel to serve different functions - maintaining compact overall size while providing localized areas with sufficient spacing for borescope access.
Solution Approach 2:
Different pitch spacing is applied to different segments of the guide vane wheel. The first segment has pitch spacing optimized for aerodynamic performance in the reduced-size engine, while the second segment has increased pitch spacing specifically to accommodate borescope insertion. This local differentiation resolves the contradiction by providing both compactness and accessibility where needed.
2Volume of moving object
If the cascade pitch is decreased to reduce engine size, then engine compactness improves, but the space for inspection tools becomes insufficient
Solution Approach 1:
The guide vane wheel is divided into two distinct segments: a first segment with guide vanes having a first pitch spacing, and a second segment with guide vanes having a second pitch spacing. This segmentation allows different regions of the same wheel to serve different functions - maintaining compact overall size while providing localized areas with sufficient spacing for borescope access.
Solution Approach 2:
Different pitch spacing is applied to different segments of the guide vane wheel. The first segment has pitch spacing optimized for aerodynamic performance in the reduced-size engine, while the second segment has increased pitch spacing specifically to accommodate borescope insertion. This local differentiation resolves the contradiction by providing both compactness and accessibility where needed.
Data Source
AI summary
A guide vane wheel of a turbomachine, has a plurality of guide vanes, forming a blade row extending radially inward in a flow path of the turbomachine, and two borescope accesses. The guide vanes form two segments each with a plurality of guide vanes circumferentially spaced apart, with the two segments having the same, constant cascade pitch and the two segments spaced such that the respective outermost guide vane adjacent to the respective other segment has an enlarged spacing in the circumferential direction from the adjacent guide vane of the other segment equal to 1.3 to 1.7 times the cascade pitch, the sum of the increased spacings being equal to 3 times the cascade pitch. The increased distance between the respective two adjacent outermost guide vanes of the two segments creates an enlarged vane passage between these guide vanes where the borescope accesses are formed.