Turbine Combustor Flow Sleeve Cooling Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current combustor designs for turbine engines face challenges in efficiently cooling the combustor liner, particularly in regions with high heat loads, where the flow of compressed air through cooling holes may not be sufficient to maintain optimal temperatures.
Innovation Solution
The design incorporates a flow sleeve with reduced diameter portions along the length of the combustor, which reduces the annular space height and can include cooling thimbles or varying cooling hole diameters to enhance the impingement of compressed air on the combustor liner, thereby improving cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the annular space height is reduced at certain portions of the flow sleeve, then the impingement force and flow velocity of compressed air on the combustor liner are increased, improving cooling effectiveness, but the flow passage area is reduced which may impede airflow
Solution Approach 1:
The flow sleeve incorporates reduced diameter portions at specific locations where cooling is most needed, creating local variations in annular space height. This allows enhanced impingement cooling at targeted zones while preserving adequate flow passage area in other regions, thus resolving the contradiction between improving cooling effectiveness and maintaining sufficient airflow.
2Temperature
If cooling holes are provided in the flow sleeve to allow compressed air flow into the annular space, then the combustor liner is cooled, but the structural integrity and strength of the flow sleeve are reduced
Solution Approach 1:
The flow sleeve is designed with cooling holes that create a controlled porous structure. These holes allow compressed air to pass through and impinge on the combustor liner for cooling, while the overall porous architecture maintains sufficient structural integrity. The distributed pattern of holes provides cooling functionality without compromising the load-bearing capacity of the flow sleeve.
3Temperature
If the flow sleeve diameter is reduced at certain portions, then the annular space height is reduced to enhance cooling impingement, but the overall volume and weight of the flow sleeve are reduced
Solution Approach 1:
The flow sleeve features variable diameter portions that change the annular space height parameter locally. By reducing the diameter at specific zones, the design achieves enhanced cooling impingement where needed while reducing material usage and overall weight. This parameter variation allows optimization of both thermal management and weight characteristics.
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 configuration enhances cooling effectiveness by increasing the impingement force and flow velocity of compressed air on the combustor liner, particularly in hotter regions, without impeding the airflow, thus maintaining efficient operation and reducing thermal stress.
Implementation Method 1
Cooling holes may be formed in the flow sleeve to allow compressed air to pass from a position outside the flow sleeve, through the cooling holes, and into the annular space. The flow of compressed air through the cooling holes impinges on the exterior surface of the combustor liner. This flow of compressed air through the cooling holes against the outer surface of the combustor liner helps to cool the combustor liner.
Data Source
AI summary
A combustor assembly for a turbine engine includes a combustor liner and a flow sleeve which surrounds the combustor liner. Compressed air flows through an annular space located between an outer surface of the combustor liner and an inner surface of the flow sleeve. A plurality of cooling holes are formed through the flow sleeve to allow compressed air to flow from a position outside the flow sleeve, through the cooling holes, and into the annular space. The height of the annular space may vary along the length of the combustor assembly. Thus, the flow sleeve may have reduced diameter portions which result in the height of the annular space being smaller in certain locations than at other locations along the length of the combustor assembly.