Impeller Splitter Backsweep for Flatter Compressor Exit Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Centrifugal compressors face challenges in achieving improved impeller exit conditions and diffuser performance due to difficulties in achieving smooth inlet profiles, which are affected by impeller tip clearance, shroud curvature, and shock and boundary layer interactions.
Innovation Solution
The impeller design incorporates a modified impeller splitter backsweep angle relative to main blades, with splitter blades exhibiting a higher backsweep than main blades, typically differing by about 5 degrees, to improve exit flow conditions and diffuser performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional impeller design with standard splitter backsweep is used, then manufacturing is simpler, but diffuser performance and impeller exit conditions are insufficient
Solution Approach 1:
The patent applies different backsweep angles to splitter vanes versus main vanes, creating localized geometric differences optimized for specific flow regions. The splitter vanes have a first backsweep angle while main vanes have a second backsweep angle, allowing each region to be optimized for its specific flow requirements, thereby improving overall diffuser performance and impeller exit conditions.
Solution Approach 2:
The patent modifies the geometric parameter of the splitter vane backsweep angle to optimize performance. By changing the backsweep angle parameter of the splitter vanes relative to the main vanes, the design achieves improved flow conditions at the impeller exit, which directly enhances diffuser performance and overall compressor efficiency.
2Productivity
If splitter backsweep angle is increased to improve exit flow conditions, then diffuser performance improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies different backsweep angles to splitter vanes versus main vanes, creating localized geometric differences optimized for specific flow regions. The splitter vanes have a first backsweep angle while main vanes have a second backsweep angle, allowing each region to be optimized for its specific flow requirements, thereby improving overall diffuser performance and impeller exit conditions.
Solution Approach 2:
The patent modifies the geometric parameter of the splitter vane backsweep angle to optimize performance. By changing the backsweep angle parameter of the splitter vanes relative to the main vanes, the design achieves improved flow conditions at the impeller exit, which directly enhances diffuser performance and overall compressor efficiency.
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
A centrifugal compressor (601) of an aircraft gas turbine engine includes an impeller (610) having a hub (620), main and splitter vanes (630, 640), and a shroud (650) surrounding the hub (620) and the main and splitter vanes (630, 640) to form a flow path (651) from an inducer portion (652) at an upstream side of the impeller (610) to an exducer portion (653) at an impeller exit (654). The main vanes (630) extend from the inducer portion (652) to the exducer portion (653) and the splitter vanes (640) are interleaved with the main vanes (630) and extend to the exducer portion (653) from an impeller mid-point. Each main and splitter vane (630, 640) includes, at the impeller exit (654), a trailing edge (660, 670), and, for one or more pairs of main and splitter vanes the trailing edge (670) of the splitter vane (640) exhibits backsweep of a first degree, and the trailing edge (660) of the main vane (630) exhibits backsweep of a second degree.