Compressor Case Vertical Split Flange Stiffening
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Solution Overview
Problem
In gas turbine engines, variations in tip clearances between blade tips and the compressor case reduce engine performance, efficiency, and stall margin, necessitating effective control of blade tip clearances to maintain compressor efficiency and operability.
Innovation Solution
Orienting the split flange of the compressor case on a vertical plane instead of a horizontal plane increases the case stiffness for bending and reduces out-of-round deflection, thereby maintaining tip clearances and improving engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the split flange is oriented on a horizontal plane (conventional design), then the engine structure is simplified and manufacturing is easier, but the case bending stiffness is reduced and out-of-round deflection increases
Solution Approach 1:
The patent applies dimensionality change by reorienting the split flange from a horizontal plane to a vertical plane. This spatial reconfiguration transforms the structural geometry to align with the engine's neutral bending axis, thereby increasing the case bending stiffness without adding additional components or complexity to the overall design.
2Manufacturing precision
If the split flange is oriented on a horizontal plane, then manufacturing and assembly are simpler, but tip clearance control deteriorates due to increased out-of-round deflection
Solution Approach 1:
By changing the flange orientation from horizontal to vertical, the patent addresses tip clearance control through geometric optimization. The vertical orientation positions the flange seams to provide structural support that minimizes out-of-round deflection during operation, thereby improving tip clearance consistency while maintaining straightforward manufacturing and assembly procedures.
3Reliability
If larger tip clearances are designed to accommodate clearance fluctuation, then compressor operability is improved, but engine performance deteriorates in terms of power output and efficiency
Solution Approach 1:
The patent applies preliminary anti-action by proactively reducing out-of-round deflection through optimized flange orientation before clearance fluctuation problems occur. The vertical flange configuration pre-establishes structural rigidity that counteracts operational deflections, allowing the compressor to maintain tighter tip clearances with improved reliability rather than requiring larger clearance margins that would reduce power output and efficiency.
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 vertical orientation of the split flange enhances bending stiffness and reduces out-of-round deflection, leading to improved engine performance by maintaining consistent tip clearances and enhancing operational efficiency.
Implementation Method 1
a split flange oriented on a horizontal plane will be on the neutral bending axis of the engine and will not influence the case bending stiffness nor out of round deflection. This invention orients the split flange in such an engine on the vertical plane, where by virtue of the parallel axis theorem of mechanics the flange will substantively increase the case stiffness for bending
Data Source
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AI summary
An engine case (200) may include a first half (202) and a second half (206). The first half (202) may have a semiannular geometry with a first flange (204) located at a circumferential edge of the first half (202). The second half (206) may also have a semiannular geometry. The second half (206) may further include a flange (208) located at a circumferential edge of the first half (202). The second flange (208) may be aligned with the first flange (204) and mechanically coupled to the first flange (204). The first flange (204) and the second flange (208) may be configured to substantially align with an engine mounting point (212). The engine case (200) may also have an annular geometry.