Variable Vane Angle Swirler for Combustor Jet Stability
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Solution Overview
Problem
Existing gas turbine engine combustors face challenges in optimizing swirling flow for jet stability, controlled flow distribution, and component durability due to constant vane angles in swirler assemblies, leading to instability and potential autoignition risks.
Innovation Solution
The implementation of primary and secondary swirlers with varying vane angles, where the forward edge is oriented at a different angle than the aft edge, decouples vane flow from ferrule purge jets, reduces jet instability, and provides controlled flow distribution by transitioning from low to high swirl, reducing autoignition risks and improving pressure drop across the swirler vanes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If constant vane angle swirlers are used, then the structure is simple, but jet stability deteriorates and autoignition risk increases
Solution Approach 1:
The swirler vane is designed with different vane angles at different radial positions: a first vane angle at the forward edge and a second vane angle at the aft edge, where the second angle differs from the first. This local variation in vane angle creates differentiated flow characteristics across the swirler outlet, improving jet stability and reducing autoignition risk while maintaining reasonable structural complexity
Solution Approach 2:
The variable vane angle design creates a dynamic flow transition from low swirl at the forward edge to high swirl at the aft edge. This dynamic swirl transition optimizes the flow distribution and stabilizes the jet, preventing the instability and autoignition issues associated with constant vane angle designs
2Ease of manufacture
If constant vane angle swirlers are used, then manufacturing is easier, but flow distribution control deteriorates
Solution Approach 1:
The swirler incorporates local quality variation through different vane angles at different locations. The forward edge has a first vane angle optimized for initial flow attachment, while the aft edge has a second vane angle optimized for flow distribution control. This local differentiation achieves precise flow control without requiring complex manufacturing processes
Solution Approach 2:
The invention changes the geometric parameter of the vane angle along the flow direction. By transitioning from a constant vane angle to a variable vane angle (first angle at forward edge, second angle at aft edge), the flow distribution is precisely controlled, optimizing both mixing and stability characteristics
3Device complexity
If constant vane angle swirlers are used, then the design is simpler, but pressure drop optimization deteriorates
Solution Approach 1:
The variable vane angle design creates a dynamic pressure distribution along the flow path. The transition from the first vane angle at the forward edge to the second vane angle at the aft edge optimizes the pressure gradient, achieving better pressure drop characteristics and improved flow control without excessive design complexity
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
This configuration enhances jet stability, reduces combustion dynamics, and increases pressure drop, leading to improved flow distribution and reduced risk of autoignition, thereby enhancing the durability and performance of gas turbine engine combustors.
Implementation Method 1
The vanes are oriented so as to produce a swirl in the air passing through the flow channel
Data Source
AI summary
A swirler apparatus for a combustor, including: primary and secondary swirlers disposed axially adjacent to each other along a swirler centerline; the primary swirler including a plurality of primary swirl vanes arrayed around the swirler centerline; and the secondary swirler including a plurality of secondary swirl vanes arrayed around the swirler centerline, each secondary swirl vane including opposed sides bounded between opposed forward and aft edges and opposed leading and trailing edges; wherein the forward edge is oriented at a first vane angle with respect to a radial direction; wherein the aft edge is oriented at a second vane angle with respect to the radial direction; and wherein the second vane angle is different from the first vane angle.