Coriolis Optimized U-Channel Airfoil Cooling
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Solution Overview
Problem
Conventional gas turbine engine rotor blades face limitations in achieving higher turbine operating temperatures due to metal temperature constraints, which restrict the thrust-to-weight ratio improvement efforts, as existing internal cooling designs only allow one side to benefit from the Coriolis effect-enhanced heat transfer.
Innovation Solution
The design incorporates a U-shaped cooling passage arrangement on both the pressure and suction sides of the airfoil, with a first passage on the pressure side and a second passage on the suction side, both receiving cooling air and utilizing the Coriolis effect for enhanced heat transfer, and a root flag passage to purge cooling air near the trailing edge, optimizing heat management across the airfoil surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional serpentine cooling passages are used, then cooling air can be delivered through the airfoil, but only one hot wall can take advantage of Coriolis effect augmentation
Solution Approach 1:
The cooling passage is divided into multiple segments: a first serpentine passage with an up pass and down pass, and a second serpentine passage with an up pass and down pass. This segmentation allows each passage to independently utilize the Coriolis effect on opposite walls, effectively doubling the number of walls benefiting from Coriolis augmentation compared to conventional single serpentine designs.
Solution Approach 2:
Each serpentine passage is configured with specific local orientations: the first up pass is oriented to augment heat transfer on the pressure side, the first down pass on the suction side, the second up pass on the pressure side, and the second down pass on the suction side. This local quality optimization ensures that Coriolis effect augmentation is maximized on specific walls based on their thermal requirements.
2Power
If turbine gas temperature is increased to improve thrust-to-weight ratio, then engine performance improves, but metal temperature constraints of turbine blades are exceeded
Solution Approach 1:
The patent replaces conventional single serpentine cooling passages with a dual serpentine passage system that strategically utilizes the Coriolis effect. This substitution enhances the cooling efficiency by approximately twofold on both the pressure and suction sides, enabling the turbine blade to withstand higher turbine gas temperatures and thereby improve the thrust-to-weight ratio without exceeding metal temperature constraints.
Solution Approach 2:
The patent changes the cooling passage configuration parameters by introducing multiple serpentine passages with specific orientations. The first and second up passes are oriented to enhance cooling on the pressure side, while the first and second down passes enhance cooling on the suction side. This parameter change optimizes the heat transfer coefficient and allows the blade to operate at higher temperatures.
3Temperature
If cooling passages are added to enhance heat transfer on both sides, then thermal management improves, but device complexity increases
Solution Approach 1:
The patent merges two serpentine cooling passages into a unified dual serpentine system within the airfoil structure. Both passages share common features such as the root flag passage and platform passage, reducing the overall complexity compared to having completely separate cooling systems. The merging approach allows efficient thermal management on both pressure and suction sides while minimizing the increase in 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 configuration effectively enhances the heat transfer coefficient on both sides of the airfoil, allowing for improved thermal management and increased turbine operating temperatures without compromising structural integrity, thereby enhancing the thrust-to-weight ratio.
Implementation Method 1
the Coriolis effect may augment the heat transfer coefficient on the pressure side of an up pass and the suction side of a down pass
Data Source
AI summary
An airfoil includes pressure and suction side walls that extend in a chord-wise direction between a leading edge and a trailing edge. The pressure and suction side walls extend in a radial direction between a platform and a tip to provide an exterior airfoil surface. A cooling passage is arranged between the pressure and suction side walls and has a first passage along the pressure side wall and a second passage along the suction side wall. The first passage is configured to receive cooling air from a cooling air source radially inward of the platform. The second passage is configured to receive cooling air from the first passage near the tip. A root flag passage is configured to purge the cooling air from the second passage near the trailing edge.