Centrifugal Compressor Diffuser Vanelets for Incidence Angle Reduction
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Solution Overview
Problem
Centrifugal compressors face efficiency losses due to varying fluid flow angles, particularly near the shroud side of the diffuser, where it's challenging to properly contour the leading edge of vanes to match fluid flow angles, leading to increased incidence angles and reduced efficiency.
Innovation Solution
The implementation of a centrifugal compressor diffuser with a non-periodic pattern of three-dimensional vanes and vanelets, where the vanelets have a reduced axial extent and asymmetrical geometry, allowing for better alignment of fluid flow with the vanes and reducing incidence angles, thereby enhancing diffuser efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the leading edge of vanes is contoured to match fluid flow angles, then diffuser efficiency is improved, but the complexity of manufacturing and designing the vane geometry increases
Solution Approach 1:
The diffuser is divided into multiple functional zones with different vane configurations. Full-height vanes are used in the central region where flow angles are moderate, while shorter vanelets are used near the shroud where flow angles are more extreme. This segmentation allows each zone to be optimized independently for its specific flow conditions, improving overall efficiency without requiring the entire diffuser to use complex contoured vanes.
Solution Approach 2:
Different parts of the diffuser have different vane geometries tailored to local flow conditions. The vanelets near the shroud have reduced axial extent and are specifically shaped to match the local fluid flow angles, while the full-height vanes in the central region have different geometry. This local customization allows each region to operate at optimal efficiency for its specific flow characteristics.
2Productivity
If full-height vanes are used throughout the diffuser, then structural simplicity is maintained, but incidence angles increase near the shroud side reducing efficiency
Solution Approach 1:
The diffuser is divided into multiple functional zones with different vane configurations. Full-height vanes are used in the central region where flow angles are moderate, while shorter vanelets are used near the shroud where flow angles are more extreme. This segmentation allows each zone to be optimized independently for its specific flow conditions, improving overall efficiency without requiring the entire diffuser to use complex contoured vanes.
Solution Approach 2:
Instead of using full-height vanes throughout the entire diffuser, the invention applies partial action by using shorter vanelets in specific regions where they are most needed (near the shroud). This partial application of reduced-height vanes targets the specific problem area of high incidence angles without the complexity of redesigning the entire vane system.
Data Source
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AI summary
A system, in certain embodiments, includes a centrifugal compressor diffuser including a flow path having a first surface and a second surface defining opposite axial sides of the flow path. The centrifugal compressor diffuser also includes multiple vanes extending from the first surface to the second surface of the flow path. A first profile of each vane varies along an axial direction. The centrifugal compressor diffuser further includes multiple vanelets extending from the first surface toward the second surface in the axial direction. A first axial extent of each vanelet is less than a second axial extent of the flow path. In addition, a second profile of each vanelet varies along the axial direction and/or the vanelets form a non-periodic pattern around a circumference of the flow path.