Non-uniform Pin-fin Array for Gas Turbine Airfoil Cooling
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Solution Overview
Problem
Conventional pin-fin arrays in gas turbine airfoils often result in angled cooling flow, leading to less effective heat transfer and increased complexity, which can cause undue stress and fatigue due to insufficient cooling.
Innovation Solution
A pin-fin array is designed with pin-fins arranged in a non-uniform pattern, including offset positions and varying spacings to guide cooling flow radially outward, enhancing heat transfer and flow control while reducing manufacturing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a single cooling flow feed leads to a pin array with multiple outlets, then the cooling flow can be distributed to multiple outlets, but the flow through the pin array becomes angled relative to the outlets, reducing heat transfer effectiveness
Solution Approach 1:
The cooling flow distribution system is segmented into multiple individual cooling flow feeds, each leading to a corresponding pin array outlet. This segmentation allows the cooling flow to be delivered axially aligned with each outlet, eliminating angled flow and improving heat transfer effectiveness while maintaining distributed cooling coverage.
2Ease of operation
If flow straighteners are used to correct angled flow, then flow control is improved, but space and complexity are added to the pin array region
Solution Approach 1:
The pin array geometry itself is designed to perform flow straightening and direction control as a preliminary action, eliminating the need for separate flow straightener components. The pin fins are configured to guide the cooling flow axially toward the outlets, incorporating flow control functionality directly into the pin array structure.
3Ease of manufacture
If conventional pin-fin arrays are used, then manufacturing is simpler, but the cooling flow becomes angled and heat transfer effectiveness decreases
Solution Approach 1:
The pin array is designed with locally optimized pin fin geometries and spacing configurations that are specific to each outlet's requirements. This allows the pin array to be manufactured as a single piece while incorporating localized flow control features that ensure axial alignment of cooling flow with each outlet, improving heat transfer effectiveness without complicating the overall manufacturing process.
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 non-uniform pin-fin array effectively directs cooling flow, improving heat transfer efficiency, reducing flow requirements, and lowering manufacturing complexity and costs, thereby enhancing the overall performance of gas turbine airfoils.
Implementation Method 1
Convective heat transfer may be enhanced between the cooling flow and the internal metal surfaces of the airfoil by the use of pin-fin arrays, turbulators, and the like. The pin-fin arrays or the turbulators create a disruption in a surrounding boundary layer so as to increase heat transfer.
Implementation Method 2
The internal cooling flow channels may be provided with a cooling air bleed from the compressor or elsewhere. Convective heat transfer may be enhanced between the cooling flow and the internal metal surfaces of the airfoil
Data Source
AI summary
The present application provides an airfoil with a cooling flow therein. The airfoil may include an internal cooling passage, a number of cooling holes in communication with the internal cooling passage, and a number of pin-fins positioned within the internal cooling passage. The pin-fins are arranged with one or more turning openings and one or more guiding openings so as to direct the cooling flow towards the cooling holes.