Gas Turbine Exhaust Duct Strut Attachment
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Solution Overview
Problem
Gas turbine engine exhaust ducts face stress and deflection due to aerodynamic forces, leading to unwanted deformation under axial and torsional loading, which existing technologies have not adequately addressed.
Innovation Solution
A dual attachment configuration for struts within the exhaust duct, involving a lobed mixer and radially inward appendages with non-parallel fasteners, distributes load across multiple paths between the hub and shroud, enhancing load transfer and mitigating deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single attachment configuration is used for struts in the exhaust duct, then the device complexity is reduced, but the structural integrity and resistance to deformation under axial and torsional loading deteriorates
Solution Approach 1:
The attachment configuration is segmented into multiple attachment points distributed around the exhaust duct circumference. Each attachment point connects the strut to the duct structure at distinct locations, creating multiple load transfer paths that collectively enhance structural integrity while maintaining manageable complexity through modular attachment design
Solution Approach 2:
The attachment configuration transitions from a single-point attachment to a multi-dimensional distributed attachment system. Attachment points are arranged in multiple planes and angular positions around the exhaust duct, creating a three-dimensional load distribution network that resists both axial and torsional forces more effectively
2Device complexity
If load is concentrated at a single attachment point, then the device complexity is reduced, but the stress on individual components increases leading to greater deformation
Solution Approach 1:
The load transfer function is segmented across multiple attachment points rather than concentrated at a single location. Each attachment point carries a portion of the total load, dividing the stress burden among multiple components and reducing peak stresses at any individual attachment point
Solution Approach 2:
Multiple attachment points are combined to form an integrated load distribution system. The collective action of all attachment points working together creates a synergistic effect where the combined load-bearing capacity exceeds the sum of individual attachment points, effectively distributing and reducing component stress
Data Source
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AI summary
An exhaust duct (30) of a gas turbine engine (10) comprises a hub (36) defining a radially-inner surface (48) of a substantially annular exhaust gas path (66), and a strut (40) extending into the exhaust gas path (66). The strut (40) is attached to the hub (36) via a first fastener (88) at a forward fastening location (89) closer to a leading edge (54) of the strut (40) than to a trailing edge (52) of the strut (40), and via a second fastener (90) at an aft fastening location (91) closer to the trailing edge (52) than to the leading edge (54). The second fastener (90) is engaged with an appendage (56) of the strut (40). The appendage (56) is received into a receptacle (58) formed in the hub (36) open to the radially-inner surface (48).