Turbine Stator Assembly with Sliding Clearance and Gas Deflection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The issue of increased leakage and wear due to variations in mechanical rotor/stator clearance caused by thermal expansion and rotor deformation in turbomachine turbine seals, leading to overheating and reduced performance.
Innovation Solution
A stator assembly with sliding means allowing radial movement between the sealing annulus and ring sectors, incorporating deflectors to guide gas flow and mix it with cooling air, reducing temperature and maintaining consistent clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mounting clearance is provided between the abradable element and the dispenser to allow radial movement, then thermal expansion and mechanical deformation can be accommodated, but hot gases circulate through the clearance causing overheating of the sealing annulus and abradable element
Solution Approach 1:
The sealing annulus is divided into multiple segments that can move radially independently relative to the dispenser segments. This segmentation allows each segment to accommodate thermal expansion and mechanical deformation without requiring large continuous clearance, thereby reducing hot gas circulation while maintaining sealing reliability.
Solution Approach 2:
The sealing annulus is designed with dynamic radial movement capability relative to the dispenser through sliding means. This dynamic adjustment allows the sealing elements to maintain optimal contact pressure under varying thermal and mechanical conditions, preventing both overheating and excessive clearance while ensuring reliable sealing operation.
2Power
If the rotor rotates at high speed, then power output is improved, but mechanical deformation increases causing clearance variation and increased leakage
Solution Approach 1:
The sealing annulus incorporates dynamic radial movement capability that responds to centrifugal forces generated during high-speed rotation. This dynamic adjustment maintains consistent sealing clearance despite speed-induced deformation, preventing gas leakage while allowing high power output operation.
Solution Approach 2:
The sealing system utilizes changes in radial position parameters through thermal and mechanical expansion during operation. The sliding means allows the sealing annulus to adjust its radial position in response to these parameter changes, maintaining optimal sealing contact under high-speed conditions and reducing gas leakage.
3Power
If the dispenser is exposed to high temperatures, then combustion energy conversion is improved, but thermal expansion causes clearance increase and reduced sealing effectiveness
Solution Approach 1:
The sealing annulus is segmented to allow differential thermal expansion between adjacent sections. This segmentation enables each segment to expand independently, maintaining sealing contact pressure and effectiveness even when exposed to high temperatures during combustion energy conversion.
Solution Approach 2:
The sealing system exploits thermal expansion parameter changes by designing the sliding means to accommodate radial movement. This allows the sealing annulus to expand thermally while maintaining consistent clearance and sealing effectiveness, preventing the temperature-induced clearance increase that would compromise sealing performance.
Data Source
AI summary
The invention relates to a stator assembly for an aircraft turbomachine extending about an axis and including: a shroud ring, a plurality of bladed ring sectors, sliding assembly allowing relative movement between the shroud ring and each of the ring sectors, the sliding assembly including two outer annular flanges which are upstream and downstream of the shroud ring, respectively, and an inner flange of each of the ring sectors which is inserted axially between the two outer flanges, wherein each of the ring sectors includes a deflector which is supported by the inner flange of the sector and extends around the upstream annular flange of the shroud ring.