Segmented Wiper Profile for Turbine Engine Sealing Heat Reduction
Solution Overview
Problem
Turbine engine sealing assemblies experience high temperature rise due to contact between the wiper and abradable member, leading to reduced service life and performance limitations, especially under varying operating conditions.
Innovation Solution
A sealing assembly with a wiper featuring alternating primary and secondary angular segments, where the secondary segments have a different cross-sectional profile, creating discontinuities that reduce prolonged contact and chip accumulation, thereby minimizing heat generation and allowing for increased service life and installation in higher temperature environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a wiper with a constant 360° cross-sectional profile is used to improve sealing, then sealing performance is improved, but temperature rise increases significantly
Solution Approach 1:
The wiper is divided into multiple angular segments (first and second segments) around the axis of rotation, with each segment having a specific cross-sectional profile. This segmentation allows different portions of the wiper to have different functional characteristics, reducing continuous contact with the abradable member and thereby reducing temperature rise while maintaining sealing effectiveness.
Solution Approach 2:
Different angular segments of the wiper are given different cross-sectional profiles tailored to their specific functional requirements. For example, certain segments may have profiles optimized for sealing while others have profiles that minimize contact and heat generation. This local optimization resolves the contradiction between sealing performance and temperature control.
2Reliability
If the wiper and abradable member are designed for maximum sealing contact, then sealing effectiveness is improved, but service life is reduced due to high temperature
Solution Approach 1:
The wiper's segmented structure creates discrete contact zones rather than continuous contact around the entire circumference. This reduces the cumulative contact time and heat generation, extending the service life of both the wiper and abradable member while preserving sealing effectiveness through strategically positioned segments.
Solution Approach 2:
The segmented wiper design creates periodic contact patterns as the rotor rotates, rather than continuous contact. This periodic action allows for cooling intervals between contact events, reducing overall temperature rise and extending component service life while maintaining sealing performance during active contact phases.
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
The solution effectively limits heating between the wiper and abradable member, extending the service life of the sealing assembly and enabling operation in higher temperature environments, thus enhancing turbine engine performance and reducing thermal expansion of surrounding parts.
Implementation Method 1
the temperature of the sealing assembly elements rises rapidly and significantly. This high temperature rise is caused in particular by the numerous contact surfaces (or friction surfaces)
Implementation Method 2
On contact, the wiper penetrates and cuts the abradable member, generating thus material chips
Data Source
AI summary
A sealing assembly (1) for a turbine engine comprising a first element (2) and a second element (3), the first and second elements (2, 3) being concentric and in relative rotational movement with respect to each other about an axis of rotation (X), the sealing assembly (1) comprising at least one first wiper (4a) and an abradable member (5), the first wiper (4a) being annular in shape and carried by the first element (2), the first wiper (4a) extending radially towards the abradable member (5) and continuously around the axis of rotation (X), the abradable member (5) being annular in shape and carried by the second element (3), the abradable member (5) extending tangentially opposite the first wiper (4a), the first wiper (4a) comprising primary angular portions (11), each extending tangentially along a primary angular sector (11′), the primary angular portions (11) each having, in cross-section, a first constant profile, characterised in that the first wiper (4a) comprises secondary angular portions (13) each extending tangentially along a secondary angular sector (13′), the secondary angular portions (13) each having, in cross-section, a second profile different from the first profile, the number of secondary angular portions (13) being equal to the number of primary angular portions (11), the secondary angular portions (13) being interposed between the primary angular portions (11).