Dual-Pivot Flapper Valve for Gas Turbine Bleed Air
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Solution Overview
Problem
Traditional bleed valves in gas turbine engines, particularly poppet-style valves, face challenges in packaging and flow efficiency due to their bulkhead or duct-mounted designs, which are not streamlined with the engine and suffer from increased load during start-up conditions.
Innovation Solution
A self-actuating, dual-pivot flapper bleed valve design that is compact, lightweight, and minimizes radial extension, featuring independent dual-pivoting flapper bodies with springs and a streamlined configuration to reduce flow restriction and enhance packaging efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If traditional poppet-style bleed valves are used, then the valve can provide bleeding function, but the valve requires large geometric area and suffers from packaging issues
Solution Approach 1:
The valve is divided into two separate flapper bodies (first and second flappers) that pivot independently about separate axes. This segmentation allows each flapper to be smaller and more compact, improving packaging efficiency while collectively providing the required flow area when both are open
Solution Approach 2:
The dual-pivot design allows the flappers to move in multiple dimensions and orientations, enabling a more compact three-dimensional configuration that reduces the overall envelope volume compared to traditional linear poppet valve designs
2Ease of operation
If traditional bulkhead or duct mounted bleed valves are used, then the valve can be installed, but the valve is not streamlined with the engine and increases radial extension
Solution Approach 1:
The dual-pivot flapper valve is integrated directly into the compressor housing structure, merging the valve function with the existing engine architecture. This eliminates the need for separate bulkhead or duct mounted installations, reducing radial extension while maintaining installation feasibility
Solution Approach 2:
By using two pivot axes instead of a single linear motion, the valve achieves a compact configuration that fits within the existing engine radial space, transforming the installation from an external add-on to an integrated component
3Productivity
If self-actuating dual-pivot flapper valve design is used, then the valve maximizes open area and reduces flow loss, but the valve structure becomes more complex
Solution Approach 1:
The valve is self-actuating, using the pressure differential across the flappers themselves to provide the closing force. This eliminates the need for external actuators, complex control systems, or additional mechanical components, reducing overall device complexity while maintaining self-service operation
Solution Approach 2:
The two flappers are positioned asymmetrically with respect to the flow path, with each flapper having its own pivot axis located at different positions. This asymmetric arrangement allows both flappers to be simultaneously open to maximize flow area while the pressure differential asymmetrically acts on each flapper to provide closing force
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 dual-pivot flapper valve design provides a more efficient airflow by maximizing open area, reducing flow loss, and maintaining structural integrity in high-vibration environments while being cost-effective and capable of operating at elevated temperatures, offering improved performance over traditional poppet valves.
Implementation Method 1
A resilient member biases the first and second flapper bodies to the open position
Implementation Method 2
When a pressure load across the first and second flapper bodies exceeds a biasing force of the resilient member, the first and second flapper bodies move to the closed position
Data Source
Figure 1~2
Figure 3~5
AI summary
A bleed valve (68) includes a valve body (70), a first flapper body (74a) movable relative to the valve body (70) between an open position and a closed position, and a second flapper body (74b) movable relative to the valve body (70) between an open position and a closed position. A resilient member (76) biases the first and second flapper bodies (74a, 74b) to the open position to vent bleed air. The first and second flapper bodies (74a, 74b) move to the closed position when a pressure load across the first and second flapper bodies (74a, 74b) exceeds a biasing force of the resilient member (76). A gas turbine engine (20) is also disclosed.