Gas Turbine Stator Vane Recess for Acoustic Suppression
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Solution Overview
Problem
Existing gas turbines face challenges in reducing combustion vibration due to acoustic propagation between combustors, especially when positional displacements occur during operation, leading to reduced effectiveness in suppressing acoustic propagation and increased thermal stress.
Innovation Solution
A first-stage stator vane design with a recess or protruding portion having side wall surfaces with an angle less than 90 degrees, which overlaps with a counterpart member to reduce gap formation and hinder acoustic propagation, along with cooling holes and a seal member to further suppress vibrations and thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the annular gas flow passage is divided by a side wall extension portion or baffle, then acoustic propagation between combustors is suppressed, but the effectiveness is reduced when positional displacement occurs during operation
Solution Approach 1:
The stator vane is designed with a recess portion that dynamically adapts to positional displacements. The recess portion allows the stator vane to maintain effective acoustic blocking despite changes in relative position between the combustor outlet and stator vane during operation, making the acoustic suppression function dynamic rather than static.
Solution Approach 2:
The invention introduces a recess portion with side wall surfaces forming an angle less than 90 degrees, creating a three-dimensional geometric feature that blocks acoustic propagation paths from multiple directions. This multi-dimensional approach to blocking sound waves makes the suppression more robust against positional variations.
2Ease of repair
If the stator vane is provided separately from the combustor to improve maintainability, then part replacement becomes easier, but gap formation increases due to positional displacement
Solution Approach 1:
The recess portion design allows the separately provided stator vane to accommodate positional displacements that occur during operation or assembly. The geometric configuration of the recess with angled side walls ensures that gaps are minimized even when the stator vane is installed separately and subject to positional variations.
Solution Approach 2:
The recess portion acts as an intermediary geometric feature that mediates the interface between the separately provided combustor and stator vane. This intermediate structure compensates for positional mismatches and reduces gap formation while maintaining the separability of components for ease of maintenance.
3Ease of manufacture
If the side wall extension portion is disposed at a distance from the first vane, then assembly is simplified, but the acoustic suppression effect is limited when displacement occurs
Solution Approach 1:
The recess portion with side wall surfaces forming an angle less than 90 degrees creates a geometric configuration that blocks acoustic propagation paths from multiple spatial dimensions. This multi-directional blocking capability compensates for the distance and gap issues that arise from simplified assembly configurations.
Solution Approach 2:
The invention changes the geometric parameters of the stator vane by introducing a recess portion with specific angular characteristics (less than 90 degrees). This parameter change enables the structure to maintain acoustic suppression effectiveness despite variations in assembly position and distance from the combustor.
Data Source
AI summary
A first-stage stator vane for a gas turbine includes: a first portion partially defining an airfoil which includes a pressure surface, a suction surface, and a trailing edge; and a second portion positioned at a leading-edge side of the airfoil with respect to the first portion, the second portion having a recess portion or a protruding portion. The recess portion or the protruding portion has a pair of side wall surfaces, and an angle formed between the pair of side wall surfaces is less than 90 angular degrees.