Gas Turbine Flowpath Geometry for High-Speed Compressor Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas turbine engine flowpath designs become non-optimal when decreasing the number of compressor stages and increasing rotational speed, leading to decreased performance due to suboptimal flowpath geometries and increased tip clearance, which results in flow separation and reduced efficiency.
Innovation Solution
The design incorporates a core housing with an inlet case and intermediate case that provide flowpaths with a shaft and hub, where the inner diameter has an increasing slope angle and the outer diameter has a controlled slope angle relative to the rotational axis, along with a geared architecture connecting the fan to the shaft, and includes features like variable vanes and a low pressure bleed to stabilize airflow and reduce tip clearance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the number of compressor stages is decreased and rotational speed is increased, then the compressor can operate at higher speeds with fewer stages, but the existing flowpath designs become non-optimal leading to decreased performance
Solution Approach 1:
The patent changes the geometric parameters of the flowpath by introducing a variable slope angle configuration. The inner diameter slope angle increases from 0 to 15 degrees while the outer diameter slope angle increases from 0 to 10 degrees along the fluid flow direction. This parameter change optimizes the flowpath geometry for high-speed operation with fewer compressor stages, resolving the contradiction between increased rotational speed and maintained compressor performance.
2Device complexity
If the number of compressor stages is decreased, then the compressor structure is simplified, but tip clearance increases causing flow separation and reduced efficiency
Solution Approach 1:
The patent applies parameter changes to the flowpath geometry by configuring the inner diameter slope angle to increase from 0 to 15 degrees and the outer diameter slope angle to increase from 0 to 10 degrees along the fluid flow direction. This geometric optimization reduces tip clearance effects and prevents flow separation, maintaining compressor efficiency despite having fewer stages and simplified structure.
Data Source
AI summary
A gas turbine engine includes a core housing that includes an inlet case and an intermediate case that respectively provide an inlet case flow path and an intermediate case flowpath. A shaft provides a rotational axis. A hub is operatively supported by the shaft. A rotor is connected to the hub and supports a compressor section. The compressor section is arranged in a core flow path axially between the inlet case flow path and the intermediate case flow path. The core flowpath has an inner diameter and an outer diameter. At least a portion of inner diameter has an increasing slope angle relative to the rotational axis. A bearing is mounted to the hub and supports the shaft relative to one of the intermediate case and the inlet case.