Airfoil Turn Channel Split Legs Radial Cooling Passage
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Solution Overview
Problem
Traditional airfoil designs for gas turbine engines face challenges in efficiently cooling complex channel geometries, as existing serpentine flow configurations are inadequate for turning cooling air between channels that are not directly next to each other, leading to flow detachment and pressure loss.
Innovation Solution
The airfoil features a radial cooling passage that is flow isolated from the first and second cooling channels, with a neck portion extending through the region between the channel legs, and a turn channel that splits into these legs, allowing for smooth flow transition with diffusion angles of no greater than 15 degrees, and cross-sectional area variations that maintain flow continuity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional serpentine flow configurations are used to cool complex channel geometries, then cooling coverage is improved, but flow detachment and pressure loss occur due to inadequate turning capability between non-adjacent channels
Solution Approach 1:
The turn channel is segmented into multiple legs (first leg, second leg, third leg) that sequentially connect non-adjacent cooling channels. This segmentation allows the cooling air to progress through discrete steps rather than attempting a single large turn, maintaining flow attachment and reducing pressure loss while achieving cooling coverage across complex geometries.
Solution Approach 2:
The turn channel extends in the spanwise direction (perpendicular to the chordal axis) to connect cooling channels that are not adjacent in the chordal direction. By utilizing the spanwise dimension, the design enables cooling of complex geometries where channels are separated in multiple spatial dimensions, avoiding flow detachment that would occur with traditional planar serpentine paths.
2Temperature
If turn channels connect non-adjacent cooling channels, then cooling coverage of complex geometries is improved, but flow detachment occurs due to sharp turns
Solution Approach 1:
The turn channel employs curved transitions between legs rather than sharp angular changes. The curved geometry allows cooling air to turn smoothly between non-adjacent channels, maintaining flow attachment and preventing detachment while achieving the necessary connection between distant cooling channels for effective cooling coverage.
Solution Approach 2:
The turn channel geometry is designed with varying cross-sectional areas along its length, with diffusion sections that expand the flow area to reduce velocity and prevent flow separation. This dynamic adjustment of flow parameters along the channel path enables reliable flow transition between non-adjacent channels without detachment.
3Temperature
If multiple channel legs are used to connect non-adjacent channels, then cooling effectiveness is improved, but device complexity increases
Solution Approach 1:
The turn channel structure serves multiple functions simultaneously: it connects non-adjacent cooling channels, provides cooling coverage for complex geometries, and maintains flow attachment through its multi-leg configuration. By integrating these functions into a single multi-leg structure rather than separate components, the design achieves improved cooling effectiveness without proportionally increasing overall device complexity.
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 design enhances cooling efficiency by reducing flow detachment and pressure loss, enabling effective cooling of airfoils in complex geometries and maintaining consistent flow rates through smooth turning of cooling air.
Implementation Method 1
the first and second channel legs increase in thickness by diffusion angles of no greater than 15 degrees
Implementation Method 2
a serpentine cooling passage configured to receive cooling air and circulate the cooling air through the airfoil
Data Source
Figure 1~2
Figure 3~4
Figure 5~7
AI summary
An airfoil (60) includes an airfoil wall (62) that defines a leading end (62a), a trailing end (62b), a first side (62c), and a second side (62d). Radially-extending ribs (64) partition the interior cavity of the airfoil into first and second cooling channels (72) and a radial cooling passage that is situated between the first and second cooling channels. The cooling channels extend to respective first and second channel ends. A turn channel connects the first and second channel ends. The turn channel splits at the first channel end into first and second channel legs (80, 82) such that there is a region between the first and second channel legs. The channels legs merge at the second channel end. The radial cooling passage extends through the region between the first and second channel legs.