Nested Turbine Seals Prevent Cooling Air Leakage
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Solution Overview
Problem
Gas turbine engines face inefficiencies due to gaps between components, leading to cooling air leakage, which affects engine performance and requires effective sealing systems to manage thermal expansion and relative movement.
Innovation Solution
A sealing system comprising a first and second body with ring and feather seals made of materials like AMS 5608 Cobalt, utilizing interference loading and pressure differentials to maintain contact and seal gaps between components, allowing for relative movement and thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cooling air is used to cool the turbine section, then the turbine temperature is reduced, but cooling air leakage through gaps reduces system efficiency
Solution Approach 1:
The sealing system employs nested seals where an inner seal and outer seal are positioned concentrically within the turbine vane assembly. The inner seal is received within a recess of the turbine vane, while the outer seal is positioned in a corresponding recess of the TOBI, creating a nested configuration that seals the gap between the rotating TOBI and stationary turbine vane, preventing cooling air leakage
Solution Approach 2:
The sealing system introduces seal elements (inner seal and outer seal) as intermediary components between the TOBI and turbine vane. These seals act as mediators that physically block the gap between components, preventing the harmful leakage of cooling air while allowing the system to maintain its cooling function
2Loss of energy
If seals are installed to prevent cooling air leakage, then energy efficiency is improved, but the system must accommodate thermal expansion and relative movement
Solution Approach 1:
The sealing system employs dynamic seal elements that can move relative to each other and the component surfaces. The inner seal and outer seal are designed with flexibility and clearance allowances that enable them to accommodate thermal expansion, vibration, and relative movement between the rotating TOBI and stationary turbine vane, maintaining sealing effectiveness under varying operating conditions
Solution Approach 2:
The sealing system accounts for parameter changes by designing seals with appropriate clearance tolerances and material properties that allow for thermal expansion. The gap dimensions, seal material selection, and mounting clearances are specifically designed to maintain effective sealing across the expected range of temperature and dimensional changes during turbine operation
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 sealing system effectively prevents cooling air leakage by aligning and overlapping seals to seal gaps, maintaining contact through pressure differentials, thereby enhancing engine performance and efficiency.
Implementation Method 1
maintaining contact through pressure differentials
Data Source
AI summary
A sealing system (8) for sealing a gap (134) between a first body (110) and a second body (112) includes a first seal (114) having a first portion (136) adapted to be attached to the first body (110) and a second portion (130) extending into the gap (134). The sealing system (8) also includes a second seal (116). The second seal (116) has a first portion adapted to be attached to the second body (112) and a second portion (132) extending across the gap (134). The second portion (130) of the first seal (114) and the second portion (132) of the second seal (116) are adjacent and overlapping with each other to seal the gap (134).