Pivoting Stowable Spray Bar for Gas Turbine Engine
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Solution Overview
Problem
The stationary configuration of fixed spray bars in gas turbine engine exhaust nozzles obstructs the engine flow path, leading to increased aerodynamic losses and a larger nozzle diameter, which reduces engine efficiency.
Innovation Solution
A pivoting stowable spray bar system that can be moved between a stowed position, spaced apart from the engine flow path, and a deployed position within the flow path, using a drive mechanism with an outer and inner drive ring to pivot the conduit, allowing it to deliver fuel during afterburner operation without obstructing the flow path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fixed spray bars are permanently suspended in the engine flow path, then fuel can be delivered during afterburner operation, but aerodynamic losses increase and nozzle diameter must be increased
Solution Approach 1:
The spray bar is made movable between a deployed position (within the engine flow path for fuel delivery) and a stowed position (spaced apart from the flow path to minimize aerodynamic losses). This dynamic reconfiguration allows the system to optimize performance for different operational states.
Solution Approach 2:
The nozzle is divided into functional zones: the spray bar assembly that can be independently positioned, and the main flow path. This segmentation allows the spray bar to be moved out of the way when not needed, preserving flow path integrity.
2Reliability
If fixed spray bars are permanently suspended in the engine flow path, then fuel delivery is ensured, but the overall nozzle diameter must be increased
Solution Approach 1:
The spray bar transitions from a static obstruction to a dynamic component that can be repositioned. When stowed, it clears the flow path entirely, allowing the nozzle to maintain its original optimized diameter without compromise.
Solution Approach 2:
The spray bar is moved from occupying the radial space within the flow path to being positioned axially behind or to the side of the flow path. This dimensional repositioning eliminates the need to increase nozzle diameter.
3Reliability
If the nozzle diameter is increased to accommodate fixed spray bars, then fuel delivery is maintained, but engine efficiency decreases
Solution Approach 1:
The movable spray bar allows the nozzle to operate at its optimal designed diameter for both afterburner and non-afterburner conditions, maintaining peak efficiency across all operating modes while still providing reliable fuel delivery when needed.
Data Source
AI summary
An exemplary fuel spray bar system can include a conduit, which is pivotally attached to an engine frame and configured to deliver fuel from a fuel line to an engine flow path. The system further includes a drive mechanism, which is configured to move the conduit between a stowed position and a deployed position.