Turbulator Pedestal Cooling for Gas Turbine Trailing Edges
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Solution Overview
Problem
Gas turbine engine components, particularly turbine blades, face challenges in efficiently cooling the trailing edge while minimizing cooling flow usage as inlet temperatures increase, requiring advanced technologies to enhance convective heat transfer with reduced cooling flow.
Innovation Solution
The use of refractory metal cores to create high-density patterns of cast cooling features, such as pedestals with turbulator legs within cooling passages, enhances mixing of cooling fluid and improves convective heat transfer at low cooling flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If turbine inlet temperatures are increased to improve engine thrust and cycle efficiency, then engine performance is improved, but the cooling requirements of turbine blades increase
Solution Approach 1:
The patent changes the physical parameters of the cooling passage by introducing turbulator pedestals that modify flow characteristics. The pedestals create turbulence and enhance mixing within the cooling passage, changing the heat transfer parameters to achieve better cooling efficiency at lower cooling flow rates, thereby resolving the contradiction between high temperature operation and cooling requirements.
Solution Approach 2:
The turbulator pedestals function as porous structures within the cooling passage, creating a high-density pattern of cast cooling features. These porous-like structures enhance convective heat transfer by increasing surface area and promoting fluid mixing, allowing the blade to withstand higher inlet temperatures with reduced cooling flow.
2Ease of manufacture
If conventional cooling passages are used in turbine blades, then manufacturing is simpler, but cooling efficiency is insufficient at high inlet temperatures
Solution Approach 1:
The cooling passage is segmented by introducing multiple turbulator pedestals distributed throughout the passage. These pedestals divide the cooling flow into multiple streams, enhancing mixing and heat transfer efficiency. The segmentation approach maintains manufacturing simplicity through castable features while dramatically improving cooling reliability at high temperatures.
3Temperature
If cooling flow rate is increased to improve trailing edge cooling, then cooling effectiveness is improved, but engine efficiency decreases due to higher cooling flow consumption
Solution Approach 1:
The patent changes the heat transfer parameters within the cooling passage by introducing turbulator pedestals that enhance convective heat transfer coefficients. This allows the same cooling effectiveness to be achieved at lower cooling flow rates, reducing the energy penalty associated with bled cooling air and improving overall engine efficiency.
Solution Approach 2:
The patent replaces the conventional approach of using high cooling flow rates (mechanical solution) with a heat transfer enhancement approach using turbulator pedestals. This substitution achieves the same cooling effectiveness through improved heat transfer mechanics rather than increased mass flow, thereby reducing energy losses.
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 solution effectively increases cooling efficiency at the trailing edge of turbine blades, reducing the amount of cooling flow required while maintaining engine performance and compactness.
Implementation Method 1
Some of the cooling passages may include portions having turbulence promoters that enhance the cooling effects of the cooling flow through the cooling passage
Implementation Method 2
enhance the cooling effects of the cooling flow through the cooling passage
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
A gas turbine engine component includes a structure that provides a cooling passage. The structure has a turbulator with a pedestal joining opposing first and second surfaces. The turbulator includes first and second legs spaced apart from one another and adjoining the pedestal. The first leg adjoins the second surface, and the second leg adjoins the first surface.