Multi-Position Compressor Bleed Valve for Low-Noise Turbine Bleed
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Solution Overview
Problem
Gas turbine engines face issues with space utilization and noise due to multiple bleed ducts and shear effects between bleed air and bypass flow, which complicate the control of compressor working lines and increase structural impact from high-pressure jets.
Innovation Solution
A gas turbine engine design featuring a first compressor bleed valve configured to release bleed air downstream of the turbine, with a second bleed valve optionally releasing air into the bypass duct, both allowing for variable control of bleed air through multi-position mechanisms and separate ducts to minimize noise and structural impact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple bleed ducts are provided between the engine core and bypass duct to control compressor working lines, then the compressor can be controlled to operate at the optimum working line, but the device complexity increases and space is consumed in the area between the engine core and bypass duct
Solution Approach 1:
The patent combines multiple bleed duct functions into a single bleed duct that directs bleed air to a downstream location behind the turbine. This merging approach maintains the ability to control compressor working lines while reducing the number of ducts and valves required, thereby simplifying the overall system architecture.
Solution Approach 2:
Instead of using multiple ducts radiating from the compressor to the bypass duct (radial arrangement), the invention uses a single duct that extends axially downstream behind the turbine. This dimensional change in duct routing eliminates the need for multiple apertures and reduces structural complexity.
2Ease of operation
If multiple bleed ducts and valves are used to control compressor working lines, then precise control is achieved, but the area between the engine core and bypass duct is occupied
Solution Approach 1:
The invention extracts the bleed air release function from the radial space between the engine core and bypass duct, and relocates it to the axial space downstream behind the turbine. This extraction frees up the radial area for other components while maintaining effective compressor control.
Solution Approach 2:
The bleed air path is redirected from a radial arrangement (multiple ducts crossing the annular space) to an axial arrangement (single duct extending downstream). This dimensional reconfiguration eliminates space occupation in the critical radial area between engine core and bypass duct.
3Ease of operation
If bleed air is exhausted into the bypass duct, then compressor control is achieved, but shear effect between bleed air and bypass flow creates noise and high pressure jets impact the bypass duct structure
Solution Approach 1:
The invention introduces a downstream location behind the turbine as an intermediary release point for bleed air. This intermediary position allows the high-pressure bleed air to expand and mix with lower-pressure exhaust gases before exiting, reducing shear effects and minimizing noise and structural impact compared to direct injection into the bypass duct.
Solution Approach 2:
The invention converts the potentially harmful high-pressure bleed air jet into a beneficial flow by directing it downstream where it can mix with exhaust gases. The high-pressure air, which would otherwise create noise and structural impact, is now used to enhance mixing and reduce emissions in the exhaust stream.
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 design reduces noise and structural impact by directing bleed air to a downstream location, allowing for continuous variable control of bleed air release, thereby optimizing compressor operation and reducing the need for multiple valves and ducts.
Implementation Method 1
a first compressor bleed valve in fluid communication with the compressor and configured to release bleed air from the compressor
Implementation Method 2
configured to release bleed air to a downstream location in the engine, the downstream location being downstream of the turbine
Implementation Method 3
the first compressor bleed valve is configured to open to at least two positions, to thereby release a variable amount of bleed air from the compressor
Data Source
AI summary
A gas turbine engine comprising: a compressor; a first turbine; and a first compressor bleed valve in fluid communication with the compressor and configured to release bleed air from the compressor; wherein the first compressor bleed valve is configured to release bleed air to a downstream location in the engine, the downstream location being downstream of the first turbine; wherein the first compressor bleed valve is configured to open wherein the first compressor bleed valve is configured to open to at least two positions, to thereby release a variable amount of bleed air from the compressor.