Gas Turbine Rotor Disc Lip Sealing Design
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Solution Overview
Problem
Air leakage passages at the disc/blade interface in gas turbine rotor assemblies reduce the performance and durability of rotor discs, seals, and blades due to infiltration of hot combustion gases and air, which affects the efficiency and longevity of gas turbine engines.
Innovation Solution
A rotor disc design with profiled slots and fixing members that receive a complementary profiled blade root portion, along with disc lips projecting forward to minimize air leakage, ensuring a secure and tight fit between the blades and the disc, thereby reducing air infiltration and enhancing sealing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional rotor disc design without disc lips is used, then the structure is simpler, but air leakage passages occur at the disc/blade interface reducing performance and durability
Solution Approach 1:
The rotor disc is segmented into multiple functional zones: the main disc body, the profiled slots for blade attachment, and the disc lips protruding from the front end portion. This segmentation allows each component to perform its specific function optimally while collectively eliminating air leakage passages at the disc/blade interface.
Solution Approach 2:
The disc lips extend in the axial dimension from the front end portion of the rotor disc, creating a three-dimensional sealing structure. This axial projection fills the gap between the disc and blade roots, eliminating air leakage passages that would otherwise exist in a two-dimensional disc configuration.
2Productivity
If traditional rotor disc design without disc lips is used, then manufacturing is simpler, but hot combustion gases and air infiltrate through air leakage passages affecting efficiency
Solution Approach 1:
The disc lips are integrated as a single continuous component with the rotor disc body, merging the sealing function with the structural disc. This integration ensures that the sealing surfaces are precisely aligned and eliminate air leakage passages while maintaining manufacturing efficiency through a single forming process.
Solution Approach 2:
The disc lips are positioned specifically at the front end portion of the rotor disc where air leakage passages occur. This localized addition of sealing structure targets the specific problem area without requiring modification of the entire disc, thereby maintaining ease of manufacture while improving engine efficiency.
3Duration of action of stationary object
If traditional rotor disc design without disc lips is used, then the structure is less complex, but heat transfer increases affecting component longevity
Solution Approach 1:
The disc lips act as an intermediary sealing element between the rotor disc and the blade roots. This intermediary structure prevents direct contact and heat transfer pathways between the hot combustion gases and the disc/blade components, thereby reducing heat transfer and extending component longevity.
Solution Approach 2:
By segmenting the disc structure to include separate disc lips, the thermal path is interrupted. The disc lips create thermal barriers that prevent direct heat transfer from the combustion gases to the rotor disc and blades, thereby reducing thermal stress and extending component life.
Data Source
AI summary
A rotor disc of a gas turbine rotor assembly is provided. The rotor disc may support a plurality of blades attached thereto. The rotor disc may have a plurality of fixing members defined therein through its peripheral surface and circumferentially spaced apart from one another. The fixing members may extend axially from a front end portion to a rear end portion of the disc. Profiled slots may be defined between pairs of adjacent ones of the fixing members and may be configured to receive complementary profiled blade root portions. A plurality of disc lips may project axially forward from a surrounding surface of the disc in the front end portion. A disc lip may be disposed at a tip portion of a fixing member, adjacent a leading edge of the disc to minimize air leakage at a disc/blade interface. A rotor assembly with such rotor disc and a plurality of blades attached thereto is also provided.