Gas Turbine Blade Damper With Cooling Flow Deflection
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Solution Overview
Problem
The direct impingement of cooling fluid streams on the suction side of gas turbine rotor blades leads to corrosion and deposit buildup, reducing maintenance cycle times and longevity, and existing solutions incur performance or manufacturing cost penalties.
Innovation Solution
A vibration damper with a deflector nose is modified to redirect the cooling fluid stream, preventing direct impingement on the suction side while maintaining effective vibration damping, thereby reducing corrosion and deposit buildup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling fluid is delivered directly into the cavity to cool and ventilate, then cooling effectiveness is improved, but deposit buildup and corrosion on the suction side worsen
Solution Approach 1:
The damper acts as an intermediary component positioned within the cavity to block the direct path of the cooling fluid stream from impinging on the suction side. The damper intercepts the harmful fluid flow and redirects it, allowing the cooling function to continue while preventing the harmful impingement effect on the blade surface.
2Object-affected harmful factors
If the damper is modified to include a deflector nose to redirect cooling fluid, then corrosion and deposit buildup are reduced, but device complexity increases
Solution Approach 1:
The damper is segmented into distinct functional parts: a main body portion for vibration damping and a deflector nose portion for flow redirection. This segmentation allows each part to perform its specific function optimally while maintaining the overall simplicity of the device. The deflector nose is added as a separate element that can be integrated with the existing damper structure.
Solution Approach 2:
The modified damper structure serves multiple functions simultaneously: the main body continues to provide vibration damping while the added deflector nose provides flow redirection to prevent impingement. This multi-functionality is achieved through a single integrated component rather than requiring separate devices for each function, thereby minimizing the increase in overall device complexity.
3Duration of action of stationary object
If existing solutions are implemented to prevent impingement, then blade longevity is improved, but performance or manufacturing cost increases
Solution Approach 1:
The damper, which is already present in the system for vibration damping purposes, is utilized to also perform the function of preventing cooling fluid impingement. By modifying the existing damper structure to include a deflector nose, the system uses an already-installed component to address the impingement problem, thereby avoiding the need for additional dedicated impingement prevention devices and reducing overall system complexity and cost.
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 effectively prevents corrosion and deposit buildup on the suction side of the blades, enhancing maintenance efficiency and blade longevity without significant performance or cost penalties.
Implementation Method 1
A plurality of flexible channel members, substantially U-shaped in section are provided. Each flexible channel member has side walls connected by a base wall, each of said channel members having the free ends of its side walls in spring loaded engagement with the circumference of said rotor disc and its side walls spaced from the shanks of adjacent blades. Said flexible channel members are urged by centrifugal force during rotation of said rotor disc so that the base wall of the same engages the radially inner surface of each platform to thereby dampen vibration of the rotor blades which occur in operation.
Implementation Method 2
Said flexible channel members are urged by centrifugal force during rotation of said rotor disc so that the base wall of the same engages the radially inner surface of each platform
Data Source
Figure 1~2
Figure 3a~4
AI summary
A gas turbine engine comprising a rotor and a cooling fluid delivery system is disclosed. The rotor comprises a disc and a plurality of blades extending radially therefrom. Each blade has a suction side and a pressure side and comprises a shank, a platform and a main portion, the main portion being radially outward of the shank and separated therefrom by the platform. At least one cavity is defined, each radially inward of the platforms and between a suction side of the shank of one blade and a pressure side of the shank of an adjacent blade. The rotor comprises at least one damper, the damper comprising a main body in contact with at least one blade and a deflector nose. The deflector nose extends from the main body into the cavity, and is arranged so that in use it deflects a stream of cooling fluid incident into the cavity delivered by the cooling fluid delivery system, away from the suction side of the shank partially defining the cavity.