Centrifugal Compressor Diffuser Vanes with Constant Thickness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing centrifugal compressor diffusers face a tradeoff between performance and efficiency, with three-dimensional airfoil-type vanes offering high efficiency but poor performance in surge and choked flow regimes, while two-dimensional cascade-type vanes provide enhanced surge and choked flow performance but reduced maximum efficiency.
Innovation Solution
The use of three-dimensional non-airfoil diffuser vanes with tapered leading and trailing edges, a constant thickness section, and varying chord length and camber angle along the span, configured to match the flow variations from the impeller, reduces surge and choked flow losses and increases efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If three-dimensional airfoil-type vanes are used, then diffuser efficiency is improved, but performance in surge and choked flow regimes deteriorates
Solution Approach 1:
The diffuser vane employs different geometric characteristics at different locations: the leading edge section has a specific curvature radius, the trailing edge section has a different curvature radius, and the constant thickness section maintains uniform thickness. This local differentiation of geometric properties allows the vane to optimize both efficiency and surge/choked flow performance simultaneously
Solution Approach 2:
The invention changes the geometric parameters of the diffuser vane, specifically using a non-airfoil cross-section with a constant thickness section that constitutes more than 50% of the chord length. This parameter change from traditional airfoil sections to non-airfoil sections with constant thickness resolves the contradiction between efficiency and surge/choked flow performance
2Reliability
If two-dimensional cascade-type vanes are used, then surge and choked flow performance is improved, but maximum efficiency is reduced
Solution Approach 1:
The invention transitions from two-dimensional cascade-type vanes to three-dimensional non-airfoil vanes with constant thickness sections. This dimensional enhancement allows the vane to achieve both improved surge/choked flow performance and maintained efficiency by utilizing the additional geometric degree of freedom
Solution Approach 2:
The diffuser vane employs asymmetric geometric configuration where the leading edge section and trailing edge section have different curvature radii, and the constant thickness section is positioned specifically along the chord. This asymmetric design optimizes flow characteristics to simultaneously improve surge performance and efficiency
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system, in certain embodiments, includes a centrifugal compressor diffuser vane (18) including a leading edge (22), a trailing edge (24), and a constant thickness section (64) extending between the leading edge and the trailing edge. A radius of curvature of the leading edge (22) and a radius of curvature of the trailing edge (24) vary along a span of the vane (18). A ratio of a length of the constant thickness section (64) to a chord length of the vane (18) is at least approximately 50%, and the ratio is substantially constant along the span of the vane.