Stiffness Controlled Abradable Seal for Gas Turbine Engines
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Solution Overview
Problem
Existing gas turbine engine seal systems lack a controlled approach to determine the pressure that dictates the temperature, wear process, and durability of abradable materials, which affects the operational efficiency and longevity of the seals.
Innovation Solution
A stiffness controlled abradable seal system is introduced, featuring a static seal surface in contact with a rotating seal surface, supported by a cantilevered arm with a solid lubricant material containing MAX phase content, which determines the desired operational temperature by controlling the stiffness of the cantilevered arm and optimizing the seal interface stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure pushing the sliding interfaces together is increased to improve seal tightness, then the sealing performance is improved, but the temperature and wear process of the abradable materials worsen
Solution Approach 1:
The patent applies parameter changes by modifying the physical properties of the abradable seal material. Specifically, it controls the hardness, porosity, and compositional parameters of the abradable material to enable effective sealing at reduced interface pressures, thereby lowering the temperature and wear at the sliding interface while maintaining seal tightness
Solution Approach 2:
The patent utilizes composite materials by creating an abradable seal material with specific compositional characteristics, including controlled porosity and hardness variations. This composite structure allows the material to deform and conform to the mating surface under lower pressure conditions, achieving effective sealing without the excessive temperature and wear associated with higher pressure
2Reliability
If the pressure pushing the sliding interfaces together is increased to improve seal tightness, then the sealing performance is improved, but the durability of the abradable materials worsens
Solution Approach 1:
The patent modifies material parameters including hardness, porosity, and compositional properties of the abradable seal material to enable effective sealing at reduced interface pressures. This parameter optimization reduces the wear rate and thermal degradation, thereby extending the durability and service life of the seal while maintaining adequate sealing performance
Solution Approach 2:
The patent employs composite abradable materials with specific microstructural characteristics, including controlled porosity and hardness gradients. These composite materials provide both the conformability needed for tight sealing and the wear resistance required for extended durability, eliminating the need for high interface pressures that would compromise seal life
3Reliability
If experimentation is used to determine the interface pressure, then empirical seal performance can be achieved, but the design process becomes time-consuming and lacks systematic control
Solution Approach 1:
The patent establishes systematic relationships between material parameters (hardness, porosity, composition) and interface pressure requirements. By defining these parameter ranges and their effects on seal performance, the patent enables engineers to select appropriate material properties and calculate required interface pressures through established criteria rather than relying on time-consuming trial-and-error experimentation
Solution Approach 2:
The patent allows designers to skip extensive experimental iterations by providing direct guidance on material parameter selection and interface pressure determination. The established design criteria enable engineers to move quickly from conceptual design to implementation by selecting materials and pressures based on systematic relationships rather than empirical trial and error
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 maintains the operational temperature within a desired range, mitigates metal transfer and melting, and ensures optimal seal performance by minimizing temperature at the abrasion interface, thereby enhancing the durability and efficiency of the seal system.
Implementation Method 1
said abradeable material includes a solid lubricant material, said solid lubricant material includes a MAX phase content material
Data Source
AI summary
A stiffness controlled abradable seal system for a gas turbine engine includes a cantilevered arm that supports one of a rotating seal surface and a static seal surface, a stiffness of the cantilevered arm controlled to achieve a desired operational temperature at a seal interface, and an optimally matched abradeable seal material with required thermo-physical and friction properties to enable desired wear mechanisms and maximized sealing and durability.