Bleed Diffuser Baffles for Gas Turbine Engine Stability Margins
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Solution Overview
Problem
Maintaining adequate engine stability margins while operating compressor bleed systems in gas turbine engines, particularly during low and high power operations, is challenging due to the selective use of over-pressurized and high-temperature air.
Innovation Solution
Incorporating a baffle plate with increasing hole areas in a circumferential direction between bleed inlet passages and exit ports, allowing for controlled air distribution from higher and lower pressure locations, and utilizing electrically controlled valves to manage air supply to aircraft systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If compressed air is bled from the compressor section for aircraft systems, then air supply for aircraft systems is improved, but engine stability margins deteriorate
Solution Approach 1:
The baffle plate creates different flow conditions at different locations by varying hole sizes. Larger holes are positioned at locations where greater flow area is needed to maintain pressure uniformity, while smaller holes are positioned where less flow is required. This local variation in hole quality optimizes air distribution while maintaining engine stability.
Solution Approach 2:
The patent transitions from considering only the number of holes to incorporating the dimensional aspect of hole area. By varying the hole area in different circumferential locations, the design adds a dimensional parameter (area) to the hole configuration, enabling better control over flow distribution and pressure uniformity across the bleed system.
2Adaptability or versatility
If multiple bleed ports are packaged at different compressor locations, then air supply flexibility is improved, but maintaining adequate engine stability margins becomes more difficult
Solution Approach 1:
The baffle plate implements local quality by providing different hole areas at different circumferential positions. This allows each location to contribute optimally to the overall air supply while maintaining proper flow distribution, enabling flexible air supply from multiple locations without compromising engine stability.
Solution Approach 2:
The system maintains adaptability through the combination of multiple bleed ports and a baffle plate design that optimizes flow distribution. The varying hole areas allow the system to dynamically respond to different operating conditions while preserving engine stability margins.
3Quantity of substance
If air is bled from higher pressure locations at low power operation, then air supply for aircraft systems is improved, but combustion efficiency deteriorates due to over-pressurized and high-temperature air
Solution Approach 1:
The baffle plate provides local flow control by varying hole areas at different locations. This enables optimized air extraction from higher pressure regions while maintaining proper flow distribution, allowing adequate air supply to aircraft systems without excessive pressure and temperature that would harm combustion efficiency.
4Use of energy by moving object
If air is bled from lower pressure locations at higher power operation, then combustion efficiency is improved, but air supply quantity for aircraft systems is reduced
Solution Approach 1:
The varying hole areas in the baffle plate enable optimized air distribution when bleeding from lower pressure locations. By providing larger hole areas at strategic positions, the system can extract sufficient air quantity for aircraft systems while maintaining the combustion efficiency benefits of lower pressure bleeding.
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
Enhances engine stability by ensuring uniform air distribution and pressure uniformity, improving combustion efficiency and reducing inefficiencies in air delivery to aircraft systems.
Implementation Method 1
A baffle plate is intermediate the at least one bleed inlet passage and a bleed exit port from the gas turbine engine. The baffle plate has a plurality of holes for allowing the air to flow from the bleed inlet passage to the bleed exit port
Data Source
AI summary
A gas turbine engine includes a compressor section having a downstream most location and more upstream locations. A compressor housing surrounds the compressor rotors. A combustor is downstream of the compressor and a turbine section is downstream of the combustor. At least one bleed inlet passage bleeds air compressed from the compressor section, and delivers the air for use on an associated aircraft. A baffle plate is intermediate the at least one bleed inlet passage and a bleed exit port from the gas turbine engine. The baffle plate has a plurality of holes for allowing the air to flow from the bleed inlet passage to the bleed exit port, with an area of the holes increasing from a location adjacent the at least one bleed inlet passage and in a circumferential direction away from the at least one bleed inlet passage. An aircraft air supply system and an aircraft are also disclosed.