Segmented Liner Overlap Holder for Turbomachine Joint Durability
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Solution Overview
Problem
Existing turbomachine exhaust gas diffusers with segmented liners experience cracking and wear due to uneven load distribution and thermal expansion, particularly at the joint edges where simple tabs are used to hold overlapping segments.
Innovation Solution
A stacked plate and fastener system, including a main plate, spacer, top plate, and fasteners, is used to bias overlapping liner segments together, with additional features like tab washers and vertical plates to enhance stability and allow for thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If simple tabs are used to hold overlapping liner segments, then device complexity is reduced, but reliability deteriorates due to cracking and wear from uneven load distribution
Solution Approach 1:
The holder is divided into multiple functional components: a base plate that contacts the lower tongue, an upper plate that contacts the upper tongue, and multiple tabs distributed along the joint. This segmentation allows each component to bear specific portions of the load, distributing stresses more evenly across the joint rather than concentrating them at single attachment points.
Solution Approach 2:
The holder transitions from a two-dimensional tab arrangement to a three-dimensional stacked plate structure. The base plate and upper plate are positioned at different axial locations along the joint, creating a distributed load path through multiple dimensions. This spatial distribution reduces stress concentration and prevents the cracking that occurs with simple planar tabs.
2Strength
If overlapping liner segments are held together rigidly, then structural integrity is improved, but adaptability deteriorates due to inability to accommodate thermal expansion
Solution Approach 1:
The tab connections are designed to be flexible rather than rigid, allowing the holder to dynamically adapt to thermal expansion and contraction of the liner segments. The tabs can bend and deform elastically under thermal stresses, maintaining joint integrity while accommodating dimensional changes that occur during turbine operation.
Solution Approach 2:
The holder structure incorporates controlled flexibility through its geometric design, allowing physical parameters such as tab curvature and plate spacing to change in response to thermal conditions. This enables the joint to maintain appropriate clearance and load distribution across a range of operating temperatures.
Data Source
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AI summary
An overlap holder (100) for a segmented liner (32) of a turbomachine (10) exhaust diffuser (30) includes stacked plates (102, 104, 106) and fasteners (112). A main plate (102) includes a first face (122), an opposite second face (124), a first end (126), and an opposite second end (128). A spacer (104), which includes respective first and second faces (132, 134), engages the first face (122) of the main plate (102). A top plate (106) includes a respective first face (142) that engages the second face (124) of the main plate (102) and a respective second face (144) opposite the first face (142) of the top plate (106). A fastener (112) is disposed at each of the first end (126) and the second end (128) of the main plate (102). Each fastener extends through holes in the spacer (104), the main plate (102), and the top plate (106) to hold the spacer (104), the main plate (102), and the top plate (106) in mutual engagement to secure a first segment (34, 36, 38) of the segmented liner (32) to an adjacent second segment (34, 36, 38) of the segmented liner (32).