Turbine Blade Tip Cooling Cavity for Creep Mitigation
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Solution Overview
Problem
The operational life cycle of turbine blades, particularly those in later stages, is limited by creep, which is exacerbated by peak stresses and high temperatures at the tip shroud and fillet regions, leading to material deformation over time.
Innovation Solution
The implementation of a blade design that includes a cooling channel with a cavity within the fillet region, in downstream flow communication with the cooling channel, and features such as turbulators or partitions to enhance cooling efficiency, along with a closure plate that channels exhausted cooling fluid for improved heat management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional blade design without tip cooling cavity is used, then manufacturing is simpler, but creep performance and operational life are limited due to high temperatures and peak stresses at tip shroud and fillet regions
Solution Approach 1:
The blade is segmented into multiple functional zones including the cooling channel and the tip cooling cavity. The cavity is specifically positioned within the fillet region to segment the thermal management function from the rest of the blade structure, allowing targeted cooling where peak stresses and temperatures occur without complicating the entire blade design.
Solution Approach 2:
The tip cooling cavity introduces local quality by providing enhanced cooling specifically in the fillet region where peak stresses and high temperatures occur. This localized thermal management approach addresses the critical creep-prone area without requiring complex cooling systems throughout the entire blade, thus improving reliability while controlling overall complexity.
2Temperature
If cooling channel alone is used, then manufacturing is simpler, but cooling efficiency is insufficient to manage high temperatures at tip shroud and fillet regions
Solution Approach 1:
The cooling system transitions from a one-dimensional cooling channel to a two-dimensional cooling architecture by adding the tip cooling cavity. This dimensional expansion allows cooling fluid to access and cool the fillet region from multiple directions, significantly improving temperature control in this critical high-stress area without requiring an overly complex multi-channel system.
Solution Approach 2:
The tip cooling cavity is nested within the fillet region, creating a cavity-within-a-structure configuration. This nesting approach allows the cooling cavity to be integrated into the existing blade geometry, providing enhanced cooling capacity while minimizing additional material and structural 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 significantly improves creep performance by effectively cooling the fillet and tip shroud regions, thereby extending the operational life of turbine blades.
Implementation Method 1
a cooling channel defined therein... in downstream flow communication with the cooling channel
Data Source
AI summary
A blade includes an airfoil that extends from a root end to a tip end. The airfoil includes a cooling channel defined therein. The blade further includes a tip shroud extending from the tip end, and at least one fillet coupled between the tip end and the tip shroud. The at least one fillet includes an interior wall. The interior wall at least partially defines a cavity in downstream flow communication with the cooling channel.