Single Skin Combustor Liner Heat Transfer Augmenters
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Solution Overview
Problem
Single skin combustor liner designs in gas turbine engines face challenges in efficient heat removal due to manufacturing constraints, leading to potential material oxidation and thermal mechanical fatigue, especially in small aero engines with limited cooling air availability.
Innovation Solution
The implementation of heat transfer augmenters, such as ribs, pin fins, and fins on the cold outer surface of the single skin combustor liner, which guide and enhance the cooling air flow to increase heat exchange surfaces and distribute cooling air effectively without increasing air consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If single skin combustor liner design is used, then weight is reduced and cost is lowered, but heat removal efficiency deteriorates due to manufacturing constraints
Solution Approach 1:
The patent applies local quality by varying the distribution, size, and orientation of effusion holes in different regions of the combustor liner. The hole pattern is optimized locally to match the thermal load distribution, with higher hole density in high-heat-flux zones and adjusted angles to direct cooling flow to specific areas needing enhanced heat removal.
Solution Approach 2:
The patent changes physical parameters of the effusion holes including diameter, length, angle, and distribution pattern to optimize cooling performance. By adjusting these parameters, the design overcomes manufacturing constraints and achieves improved heat transfer efficiency while maintaining the single skin lightweight structure.
2Temperature
If cooling air consumption is increased, then heat removal capability is improved, but engine overall performance deteriorates
Solution Approach 1:
The patent optimizes the parameters of effusion holes (size, angle, distribution) to maximize cooling efficiency per unit of cooling air. This allows achieving effective wall temperature control with minimized cooling air consumption, thereby preserving engine overall performance and thermodynamic efficiency.
Solution Approach 2:
The effusion cooling system provides continuous cooling along the combustor liner surface through distributed holes, ensuring sustained heat removal throughout the combustion chamber without requiring excessive air intake, thus maintaining continuous useful cooling action with optimal air usage.
3Productivity
If cooling air is reduced, then engine performance is maintained, but durability deteriorates due to material oxidation and thermal fatigue
Solution Approach 1:
The patent applies local quality by concentrating cooling effort in regions most susceptible to thermal damage through strategically positioned and angled effusion holes. This ensures adequate protection against oxidation and thermal fatigue in critical zones while using minimal cooling air, thus maintaining durability without compromising engine performance.
Solution Approach 2:
The effusion holes act as simple, easily manufactured features that can be integrated into the single skin liner. Their straightforward geometry allows cost-effective manufacturing while providing sufficient cooling protection, making the durability solution economically viable without complex or expensive cooling systems.
4Ease of manufacture
If effusion hole size and angle are constrained by manufacturing, then manufacturing ease is maintained, but heat transfer efficiency deteriorates
Solution Approach 1:
The patent systematically varies effusion hole parameters (diameter, length-to-diameter ratio, angle relative to surface) within manufacturable ranges to optimize heat transfer. By carefully selecting and combining different parameter values, the design achieves superior cooling efficiency while remaining compatible with standard manufacturing processes and constraints.
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 solution improves heat transfer efficiency and reduces thermal mechanical stress, enhancing the durability and performance of single skin combustor liners by ensuring uniform temperature distribution and reducing the risk of over-cooling or under-cooling regions without increasing cooling air usage.
Implementation Method 1
a flow of cooling air is supplied to a radially outer surface of the radially inner liner
Implementation Method 2
heat removal from the combustion chamber walls
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A combustor (16) for a gas turbine engine (10) comprises a single skin liner (20a, 20b) defining a combustion chamber (22). The single skin liner (20a, 20b) has an inner surface facing the combustion chamber (22) and an outer surface (36) exposed to a coolant flow discharged in a plenum (17) extending from the outer surface (36) of the single skin liner (20a, 20b) to the engine casing (26). Cooling holes (30) extend through the single skin liner (20a, 20b). Open flow guiding channels (37) are provided on the outer surface (36) of the single skin liner (20a, 20b), the open flow guiding channels (37) being uncovered and aligned with the flow of air over the outer surface (36) of the single skin liner (20a, 20b).