Dual-Wall Impingement Combustor Tile Cooling
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Solution Overview
Problem
Gas turbine engine combustor walls face high temperatures, leading to premature wear and attachment issues with conventional cooling methods, which fail to effectively manage thermal stress and leakage.
Innovation Solution
A dual-wall impingement, convection, effusion (DICE) combustor tile design with a cold skin and hot tile assembly, where air is fed through the cold skin to impinge on the hot tile, enhanced by turbulators or pin fins, and maintained by studs and standoffs for robust attachment, reducing temperature exposure and leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling air is directed into a gap between spaced outer and inner walls, then the inner wall is cooled, but hot spots form in certain areas of the combustion chamber wall
Solution Approach 1:
The patent employs effusion cooling where cooling air is introduced through porous material or small holes in the inner wall tiles, creating a distributed pattern of cooling jets. This pneumatic approach replaces the conventional gap-based convection cooling with a more uniform effusion cooling pattern that eliminates hot spots while maintaining effective temperature control of the combustion chamber walls.
2Productivity
If high compressor exit pressures and temperatures are used, then thrust and fuel consumption improve, but the combustor chamber experiences much higher temperatures
Solution Approach 1:
The patent introduces cooling air as an intermediary substance that flows through the dual-wall structure and porous tiles to absorb and carry away excess heat from the combustion chamber walls. This intermediary cooling airflow enables the system to operate at high compressor exit temperatures for improved productivity while maintaining wall temperatures within safe limits through active thermal management.
3Temperature
If a doubled walled combustion chamber is used with cooling air in the gap, then wall cooling is achieved, but cooling flow requirements are high
Solution Approach 1:
The patent utilizes porous material in the inner wall tiles to enable effusion cooling, where cooling air passes through the porous structure and emerges as numerous small jets across the wall surface. This porous approach dramatically improves cooling efficiency compared to gap convection, reducing the total quantity of cooling air required while achieving superior wall temperature control and eliminating hot spots through uniform heat distribution.
4Temperature
If conventional cooling methods are used, then some cooling is provided, but attachment loss and component distress occur under harsh environmental conditions
Solution Approach 1:
The patent employs composite construction with inner wall tiles made of heat-resistant materials capable of withstanding extreme combustion temperatures. These composite tile structures, potentially combining ceramic matrix composites or other high-temperature materials with metal bonding layers, provide both thermal protection and mechanical integrity, preventing tile attachment loss and component distress in the harsh combustion environment while enabling effective cooling.
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 DICE tile assembly provides enhanced temperature capability with reduced cooling flow requirements, improved reliability, and reduced parasitic leakage, resulting in improved durability and efficiency.
Implementation Method 1
air is fed through the cold skin to impinge on the hot tile
Implementation Method 2
air is fed through the cold skin to impinge on the hot tile
Implementation Method 3
enhanced by turbulators or pin fins
Data Source
AI summary
A gas turbine engine includes a combustor having a dual-wall impingement convention effusion combustor tile assembly. The dual-wall tile assembly provides a cooling air flow channel and attachments for securing the tile to the cold skin liner of the combustor. Cooling is more efficient in part due to the dual wall construction and in part due to reduced parasitic leakage, and the design is less sensitive to attachment features which operate at lower temperatures.