Rotor Blade Platform Cooling Structure for Thermal Fatigue
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine engine airfoil platforms experience thermal mechanical fatigue due to temperature differences, leading to early wear and failure, as existing cooling structures are insufficiently effective in managing thermal loads and convective cooling.
Innovation Solution
A multi-chamber platform cooling structure with heat transfer enhancement features such as trip strips, pedestals, and pin fins, along with a cooling cover apparatus and retention mechanisms like welds and defined gaps, to improve convective heat transfer and structural support, while allowing for efficient fluid flow and pressure management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cooling structures are used in gas turbine engine platforms, then the structure is simple to manufacture, but thermal mechanical fatigue occurs due to insufficient heat transfer efficiency
Solution Approach 1:
The cooling chamber is divided into multiple segments or zones using ribs that extend from the platform inner surface to the cover apparatus. This segmentation allows different regions to be cooled independently with optimized cooling air distribution, improving heat transfer efficiency and thermal fatigue resistance while maintaining a manageable structural complexity through modular design
Solution Approach 2:
The patent introduces three-dimensional heat transfer enhancement features such as pin fins, pedestals, and trip strips within the cooling chamber. These features add vertical dimensionality to the cooling process, increasing the heat transfer surface area and convective efficiency without significantly increasing the overall platform complexity, as they are integrated within the existing cooling chamber volume
2Temperature
If heat transfer enhancement features are added to the cooling chamber, then convective heat transfer is improved, but manufacturing complexity increases
Solution Approach 1:
The patent combines multiple functions into integrated structures: the cover apparatus serves both as a sealing element and a structural component that can be welded to the platform; the ribs serve both as cooling chamber dividers and as attachment points for heat transfer enhancement features; the pin fins, pedestals, and trip strips are designed to be formed or attached as part of the cooling chamber assembly, reducing the number of separate manufacturing steps and improving ease of manufacture while maintaining enhanced convective heat transfer
3Reliability
If cooling air flow is increased to improve cooling, then thermal fatigue is reduced, but pressure losses and flow separation increase
Solution Approach 1:
The patent implements local quality optimization by providing different cooling air flow characteristics in different regions of the platform. The segmentation ribs and heat transfer enhancement features are strategically positioned to direct cooling air to areas of highest thermal stress, improving thermal fatigue resistance where needed most while minimizing overall pressure losses by avoiding excessive cooling in lower-stress regions. The inflow channel geometry is also optimized to reduce flow separation and pressure losses while maintaining effective cooling air distribution
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
Enhances heat transfer efficiency and structural strength, effectively mitigating thermal mechanical fatigue and improving the durability of gas turbine engine components by optimizing cooling air distribution and retention within the platform.
Implementation Method 1
A multi-chamber platform cooling structure with heat transfer enhancement features such as trip strips, pedestals, and pin fins, along with a cooling cover apparatus and retention mechanisms like welds and defined gaps, to improve convective heat transfer
Implementation Method 2
heat transfer enhancement features disposed within the first cooling chamber. The heat transfer enhancement features may include at least one of trip strips (of various orientations), pedestals (of various diameter and spacing), and/or pin fins (of spherical, conical, triangular, elliptical shapes)
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A rotor blade (68) includes an airfoil section (100) with a cooling cavity (101) and a platform (200). The platform (200) has a platform cooling apparatus (230) having a cooling chamber (234) forming a channel disposed at least partially through the platform (200) and an inflow channel (232) in fluidic communication with the chamber (234) and the cooling cavity (101) so that cooling air may travel from the cooling cavity (101) of the blade airfoil section (100) and into the platform cooling apparatus (230). The platform cooling apparatus (230) has a cooling cover apparatus (250) at least partially fluidically sealing the platform cooling apparatus (230).