Gas Turbine Stator Vanes with Non-Uniform Spacing for Vibration Control
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Solution Overview
Problem
Existing gas turbine engines experience severe vibratory responses due to uniform vane spacing in stator vanes, which excite rotor blades at specific frequencies, leading to potential operational issues.
Innovation Solution
Implementing a circumferential row of stator vanes with non-uniform vane spacing, dividing the vanes into two groups with different spacings, to shift and bias the harmonic response away from the main driving frequency, thereby reducing the severity of vibratory responses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If uniform vane spacing is used in stator vanes, then manufacturing is simplified and structural symmetry is maintained, but severe vibratory responses are excited at specific frequencies
Solution Approach 1:
The patent applies asymmetry by introducing non-uniform spacing between adjacent stator vanes in the circumferential row. Specifically, at least one spacing interval between adjacent vanes is made different from the other spacing intervals, breaking the symmetric pattern. This asymmetric spacing configuration prevents the excitation of strong vibratory responses at specific frequencies while maintaining acceptable manufacturing complexity through controlled variations in spacing.
2Object-affected harmful factors
If non-uniform vane spacing is implemented to reduce vibratory responses, then harmonic response control is improved, but manufacturing complexity increases
Solution Approach 1:
The patent applies local quality by making spacing adjustments only in specific local regions rather than throughout the entire circumferential row. The non-uniform spacing is implemented such that at least one spacing interval between adjacent vanes is modified, while other spacing intervals may remain uniform or differently modified. This localized approach achieves effective harmonic response control and vibratory reduction while minimizing the overall manufacturing complexity compared to completely non-uniform spacing configurations.
Data Source
AI summary
A circumferential row of vanes for a gas turbine engine, the circumferential row of vanes has non-uniform spacing. The circumferential row of vanes includes a plurality of stator vanes arranged circumferentially about an inner ring. The plurality of stator vanes include a first group of stator vanes having a first spacing between adjacent stator vanes of the first group of stator vanes and a second group of stator vanes having a second spacing between adjacent stator vanes of the second group of stator vanes. The second spacing is from two percent to eleven percent greater than a nominal uniform vane spacing or from two percent to eleven percent lesser than the nominal uniform vane spacing, the nominal uniform vane spacing being defined by a total number of the plurality of stator vanes. An engine includes the circumferential row of vanes.