Blade Outer Air Seal Intersegment Gap Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing blade outer air seal technologies in gas turbine engines face challenges in effectively sealing the gaps between seal segments, leading to gas leakage and inefficiencies, particularly when using ceramic matrix composite materials which are difficult to mount and have limitations in thermal expansion compatibility.
Innovation Solution
A blade outer air seal assembly with intersegment seals arranged between flow guide segments, featuring a protrusion for anti-rotation, a notch for engagement, and a spacer to minimize leakage, along with a support structure engaging hooks and lips, utilizing ceramic matrix composite or metallic materials for enhanced sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If blade outer air seal segments are used to seal gaps, then sealing efficiency is improved, but gas leakage between segments occurs
Solution Approach 1:
An intersegment seal is introduced as an intermediary component between adjacent blade outer air seal segments. This seal fits into a gap defined by the flow guide and the blade outer air seal, specifically engaging with a notch at the circumferential end. The intersegment seal acts as a mediator that bridges the gap between segments, preventing gas leakage while maintaining the segmented structure's benefits.
2Temperature
If ceramic matrix composite materials are used for blade outer air seal, then high temperature resistance is improved, but ease of manufacture deteriorates
Solution Approach 1:
The blade outer air seal is divided into multiple segments arranged circumferentially about the axis. Each segment can be manufactured separately using ceramic matrix composite materials, allowing for easier fabrication and assembly. The segments are joined together to form a complete seal, reducing the complexity of manufacturing a single large component while maintaining high temperature resistance.
Solution Approach 2:
The intersegment seal serves as a mediator that facilitates the connection between ceramic matrix composite segments. By providing a specialized sealing component that fits into the gap between segments, it enables the assembly of segmented structures while maintaining sealing integrity, thus improving ease of manufacture without sacrificing temperature resistance.
3Adaptability or versatility
If segmented flow guide is used, then adaptability to thermal expansion is improved, but device complexity increases
Solution Approach 1:
The flow guide is divided into multiple segments arranged circumferentially, allowing each segment to move independently to accommodate thermal expansion. This segmentation enables the structure to adapt to dimensional changes due to thermal effects while maintaining the overall integrity of the assembly. The segments can expand and contract independently, providing adaptability without requiring complex expansion joints or mechanisms.
Solution Approach 2:
The intersegment seal acts as an intermediary that connects the segmented flow guide components. It fits into the gap between flow guide segments and blade outer air seal segments, providing a simple yet effective means of joining segments while allowing for relative movement due to thermal expansion. This approach maintains device simplicity while achieving adaptability.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A blade outer air seal assembly (105;205) includes a support structure. A blade outer air seal (106) extends circumferentially about an axis (A) and is mounted in the support structure (112). A flow guide (138) has a plurality of flow guide segments arranged between the blade outer air seal (106) and the support structure (112). An intersegment seal (152) is at a circumferential end (C1) of at least one of the flow guide segments.