Curved-Fin Heat-Exchanging Partition Wall for Airflow Separation Control
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Solution Overview
Problem
The existing heat exchange bulkheads for aircraft engines suffer from reduced heat transfer efficiency due to cooling air separation over the pins, leading to decreased cooling effects on high-temperature components.
Innovation Solution
A heat exchange bulkhead with fins having a curved shape and upstream fillets that are concavely curved, designed to improve airflow continuity and reduce secondary flows, enhancing heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If pins with rectangular shape are provided on the inner wall member, then the structure is simple to manufacture, but cooling air separation occurs over the entire outer peripheral surface resulting in decreased heat transfer efficiency
Solution Approach 1:
The patent applies curvature by providing pins with a curved outer peripheral surface instead of a rectangular shape. Specifically, the pin has a semicircular cross-section with a radius of curvature R1, and the outer peripheral surface has a radius of curvature R2. This curved geometry prevents cooling air separation by allowing the airflow to follow the contour of the pin, thereby maintaining heat transfer efficiency while keeping the manufacturing process relatively simple.
2Temperature
If cooling air flow rate is increased to improve cooling effect, then the cooling effect on high-temperature components improves, but the volume of compressed air required increases
Solution Approach 1:
The patent changes the geometric parameters of the cooling structure by providing pins with specific curved dimensions. The pin has a length L1 in the axial direction, a semicircular cross-section with radius R1, and an outer peripheral surface with radius of curvature R2. These parameter optimizations enhance the heat transfer efficiency per unit volume of cooling air, allowing effective cooling with reduced compressed air volume.
3Device complexity
If rectangular pins are used, then the device complexity is low, but secondary flows are generated reducing cooling efficiency
Solution Approach 1:
The patent eliminates secondary flows by replacing rectangular pins with curved pins having a semicircular cross-section. The curved outer peripheral surface with radius of curvature R2 allows cooling air to flow smoothly along the pin surface without separation, preventing the formation of secondary flows that would reduce cooling efficiency. This maintains relatively simple device complexity while significantly improving cooling performance.
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 design suppresses cooling air separation and secondary flows, improving heat transfer efficiency and promoting lean combustion, while reducing the need for compressed air volume and minimizing powder accumulation.
Implementation Method 1
the pin has a rectangular shape when the pin is viewed in a direction extending from the inner wall member. This may result in the cooling air separating over the entire outer peripheral surface of the pin. When separation of the cooling air occurs, the heat transfer efficiency between the high-temperature components and the cooling air decreases
Implementation Method 2
heat exchange bulkhead for air-cooling high-temperature components of an aircraft engine... improve the heat transfer efficiency between high-temperature components and a gaseous refrigerant (cooling air)
Data Source
AI summary
A heat-exchanging partition wall for air cooling a high-temperature component of an aircraft engine is provided with a wall that defines a cooling flow path through which cooling air flows along a first direction between the wall and a cooling surface of the high-temperature component, at least one fin that is provided on the cooling surface of the high-temperature component and that has a curved shape in which the front surface including at least the leading edge is convex toward the upstream side in the first direction when viewed from the direction opposite to the cooling surface, and an upstream fillet that extends along the upstream side in the first direction from the front surface of the at least one fin until connecting to the cooling surface and that has a curved surface that is curved in a concave shape.