Combustor Liner Cooling Hole Density Pattern
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Solution Overview
Problem
Existing combustor liners experience uneven temperature distributions and elevated temperatures near large openings, leading to potential oxidation, coating failure, and thermal stresses due to disrupted cooling airflow, which degrades their effectiveness, integrity, and lifespan.
Innovation Solution
A combustor assembly with closely spaced cooling holes arranged in specific patterns and densities, including a densely spaced first group upstream and downstream of large openings, a second group with intermediate spacing, and a third group with greater distance, to enhance cooling airflow and maintain even temperature distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling holes are arranged in a dense grouping upstream of larger openings to distribute ample cooling airflow, then cooling effectiveness in localized areas is improved, but the greater flow through the larger openings disrupts the cooling air flow and causes deficiency downstream
Solution Approach 1:
The patent applies local quality by varying the density of cooling holes in different regions. The first group of cooling holes is densely spaced upstream of large openings where cooling demand is highest, the second group has intermediate spacing in transition zones, and the third group has wider spacing in regions less affected by flow disruption. This non-uniform distribution optimizes cooling effectiveness in each specific location while accounting for local flow conditions.
Solution Approach 2:
The cooling hole pattern is segmented into three distinct groups based on their spacing and location relative to large openings. This segmentation allows each group to address specific cooling needs in different zones: the first group counters flow disruption upstream, the second group provides transition cooling, and the third group maintains cooling downstream. The segmented approach enables targeted cooling strategies for each region.
2Quantity of substance
If the amount of cooling airflow is limited for design intent, then resource allocation is optimized, but it is difficult to provide sufficient cooling throughout the entire liner uniformly
Solution Approach 1:
The patent implements local quality by concentrating cooling holes in the first group upstream of large openings where temperature elevations are most severe. This localized concentration of cooling resources addresses the most critical thermal zones with higher density holes, while regions further from large openings receive adequate cooling with lower density. This approach achieves uniform temperature distribution across the entire liner using limited cooling airflow by allocating it where most needed.
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 tailored cooling hole pattern effectively addresses temperature disparities and ensures efficient allocation of cooling airflow, reducing thermal stresses and promoting even temperature distribution across the liner, thereby enhancing its performance and longevity.
Implementation Method 1
a plurality of cooling holes supply a thin layer of cooling air that insulates the hot side of the liner from extreme combustion temperatures
Implementation Method 2
distribute ample cooling airflow in regions via film cooling and effective heat removal through the thickness of the liner by convection along the surfaces of the holes
Implementation Method 3
effective heat removal through the thickness of the liner by convection along the surfaces of the holes
Data Source
AI summary
A combustor assembly includes an inner and outer liner defining a combustion chamber. The inner and outer liners include a plurality of cooling holes spaced a specified distance apart. The cooling holes include first, second and third groups. The first group of cooling holes is the most densely spaced, followed by the second group and then the third group. The first group of cooling holes begin upstream of a leading edge of a large opening and terminates downstream of the leading edge. The increased density of cooling holes adjacent the large openings provide increased cooling airflow in areas where cooling may be affected by local disturbances in cooling airflow.