Adaptive Gas Turbine Casing for Stall Prevention
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Solution Overview
Problem
Gas turbine engines face performance deficiencies due to unstable airflow, particularly when compressor blades enter a stall condition, leading to air flow separation and pressure imbalances.
Innovation Solution
A housing with a plurality of rings and cams that define an axial gap, allowing for controlled movement of the rings to manage airflow instability by adjusting the axial gap's position in response to operating conditions, such as cruise engine speed or transonic blade speeds, thereby preventing stall conditions and enhancing engine efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the axial gap is fixed in position, then the structure is simple and stable, but the engine cannot adapt to different operating conditions and stalls occur
Solution Approach 1:
The patent applies the dynamics principle by making the axial gap movable rather than fixed. The casing structure includes a movable casing portion that can shift axially to adjust the axial gap between the compressor blades and the casing. This dynamic adjustment allows the engine to adapt to different operating conditions (such as varying speeds and loads) by optimizing the axial gap position, thereby preventing stall conditions while maintaining a relatively simple overall structure.
2Reliability
If the axial gap is reduced to prevent stall, then airflow stability improves, but the device complexity increases due to control mechanisms
Solution Approach 1:
The patent applies the parameter changes principle by dynamically adjusting the axial gap parameter based on operating conditions. The movable casing portion changes the axial position of the casing relative to the rotor, thereby modifying the axial gap parameter. This allows optimization of airflow stability by reducing the axial gap when needed (to prevent blade stall) while avoiding excessive complexity through a straightforward mechanical adjustment mechanism rather than complex active control systems.
3Device complexity
If the axial gap is increased for certain operating conditions, then device simplicity is maintained, but airflow separation and stall occur
Solution Approach 1:
The patent resolves this contradiction by implementing a dynamic axial gap adjustment mechanism. Rather than using a fixed large axial gap that would cause airflow separation, the movable casing portion allows the axial gap to be reduced dynamically when operating conditions require it. This maintains airflow stability and prevents blade stall while keeping the overall casing structure relatively simple, as the adjustment mechanism integrates into the existing casing design.
Data Source
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AI summary
A gas turbine engine (20) includes a plurality of blades (62) circumferentially spaced from each other. A plurality of rings (68) are spaced radially outward from the plurality of blade (62). At least one actuator (96) is in mechanical communication with the plurality of rings (68) for moving the plurality of rings (68) in an axial direction to create an axial gap (80) adjacent at least one of the plurality of rings (68).