Turbine Blade Inter-Blade Sealing with Cylindrical Cooling Inserts
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Solution Overview
Problem
Existing inter-blade sealing systems in turbine engines fail to provide effective cooling and uniform wear distribution, leading to potential cracks and non-uniform wear, making maintenance and blade replacement challenging.
Innovation Solution
The use of elongate cylindrical inserts with annular grooves for cooling and annular scores as wear indicators, which allow for controlled air flow and uniform wear distribution, enabling accurate maintenance and independent blade mounting/removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sheet metal box sealing system is used between blade platforms, then inter-blade sealing is provided and vibration damping is achieved, but the platforms cannot be cooled and blades cannot be independently mounted or removed
Solution Approach 1:
The sealing system is segmented into individual inserts that can be independently installed and removed with each blade, replacing the previous integrated box structure that connected multiple blades together. This allows blades to be serviced independently while maintaining sealing functionality.
Solution Approach 2:
The sealing function is extracted from the blade platform structure itself and implemented through separate insert components that can be independently managed. This extraction enables both cooling channels to be integrated into the platform while the sealing insert remains a separate serviceable component.
2Reliability
If a triangular insert is used between blade platforms, then inter-blade sealing is provided, but the insert becomes worn non-uniformly and wear is not quantifiable
Solution Approach 1:
The insert cross-section is changed from triangular to circular, allowing the insert to rotate and distribute wear uniformly across its entire circumference. The circular geometry ensures that any point on the insert surface can contact the blade platform, preventing localized wear concentration.
Solution Approach 2:
Wear indicators are incorporated into the insert design, likely using visual indicators (such as colored bands or markings) that change appearance or position as wear progresses, providing quantifiable wear measurement to determine when replacement is needed.
3Temperature
If cooling channels are added to blade platforms, then blade cooling is achieved, but the sealing system complexity increases
Solution Approach 1:
The sealing insert and cooling channel system are merged into a single integrated component. The insert contains internal cooling passages that receive cooling air and distribute it to the blade platform, combining sealing and cooling functions in one element rather than requiring separate systems.
Solution Approach 2:
The insert is designed to perform multiple functions simultaneously: providing inter-blade sealing, distributing cooling air to the blade platform, and incorporating wear indicators for maintenance monitoring. This multi-functionality reduces overall system complexity by consolidating multiple components into one.
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
The solution provides effective cooling, uniform wear distribution, and facilitates maintenance by allowing for the detection of excessive wear, ensuring reliable sealing and reducing operational costs.
Implementation Method 1
each insert being in the form of an elongate cylinder and having at least one annular groove in its outer cylindrical surface for passing air for cooling the platforms of the blades
Implementation Method 2
In operation, it is subjected to centrifugal forces and it comes to bear against the radially outer wall of the cavity and against the edge of the platforms of the adjacent blade
Data Source
AI summary
An inter-blade sealing for a turbine or compressor wheel of a turbine engine includes inserts engaged in longitudinal cavities in side edges of platforms of blades and bearing, in operation, against facing side edges of platforms of adjacent blades. Each insert has a cylindrical elongate shape and includes in its outer cylindrical surface at least one annular groove for passing platform cooling air.