Centrifugal Compressor Impeller Splitter Blade Vortex Management

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional centrifugal compressor impellers with splitter blades face inefficiencies due to interference from leakage vortices, leading to uneven flow distribution and increased losses, especially in open-type impellers with tip clearance, which complicates fluid flow and hinders high pressure ratio and efficiency.

Innovation Solution

The impeller design minimizes the distance between the leading edge of the rear full blade and the front full blade, with the splitter blade's leading edge inclined 5 to 8 degrees towards the front full blade, placing it downstream of the leakage vortex line to avoid interference and maintain even flow distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the leading edge blade angle of the splitter blade is increased to make the throat areas equal, then the throat area equality is improved, but flow separation occurs and flow distribution becomes uneven

Engineering Contradiction:
Improvethroat area equalityVSAvoidflow distribution uniformity
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The invention applies different blade angles at different locations of the splitter blade. Specifically, the blade angle at the leading edge (α1) is set to 10-20 degrees, while the blade angle at the trailing edge (α2) is set to 5-15 degrees. This local differentiation allows the leading edge to effectively equalize throat areas while the trailing edge maintains stable flow distribution, preventing flow separation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the blade angle parameters of the splitter blade from a uniform design to a differentiated design. By setting the leading edge blade angle (α1) to 10-20 degrees and the trailing edge blade angle (α2) to 5-15 degrees, the invention optimizes both throat area equality and flow distribution uniformity simultaneously, resolving the contradiction between these two parameters.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the splitter blade geometry is formed by simply cutting off the upstream side of the full blade, then the manufacturing simplicity is improved, but leakage vortex interference occurs and efficiency is reduced

Engineering Contradiction:
Improveblade geometry formationVSAvoidleakage vortex loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention applies different blade angles at different locations of the splitter blade. Specifically, the blade angle at the leading edge (α1) is set to 10-20 degrees, while the blade angle at the trailing edge (α2) is set to 5-15 degrees. This local differentiation allows the leading edge to effectively equalize throat areas while the trailing edge maintains stable flow distribution, preventing flow separation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the blade angle parameters of the splitter blade from a uniform design to a differentiated design. By setting the leading edge blade angle (α1) to 10-20 degrees and the trailing edge blade angle (α2) to 5-15 degrees, the invention optimizes both throat area equality and flow distribution uniformity simultaneously, resolving the contradiction between these two parameters.

Inventive Principle:
Principle #35Parameter changes

3Power

If the leading edge of the splitter blade is placed upstream, then the blade loading is improved, but interference with leakage vortex increases and flow separation occurs

Engineering Contradiction:
Improveblade loadingVSAvoidleakage vortex interference
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The invention applies different blade angles at different locations of the splitter blade. Specifically, the blade angle at the leading edge (α1) is set to 10-20 degrees, while the blade angle at the trailing edge (α2) is set to 5-15 degrees. This local differentiation allows the leading edge to effectively equalize throat areas while the trailing edge maintains stable flow distribution, preventing flow separation.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the blade angle parameters of the splitter blade from a uniform design to a differentiated design. By setting the leading edge blade angle (α1) to 10-20 degrees and the trailing edge blade angle (α2) to 5-15 degrees, the invention optimizes both throat area equality and flow distribution uniformity simultaneously, resolving the contradiction between these two parameters.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This configuration effectively prevents leakage vortex interference, enhancing impeller efficiency and achieving a high pressure ratio by ensuring even flow rates and reducing losses.

Implementation Method 1

the leading edge of the splitter blade is placed in a fluid flow streaming along the flow passage the full blades, on the downstream side of a leakage vortex line formed to connect the middle location of the throat to the leading edge of the front side full blade

Methodology Applied
Scientific EffectLeakage vortex: Vortex Ring

Implementation Method 2

the fluid is discharged toward the outside in the radial direction and obtains pressure increase via centrifugal force

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP2428684B1Impeller for centrifugal compressor
Publication Date: 2019.05.08 MITSUBISHI HEAVY IND LTD
  • EP2428684B1 patent drawingFigure 1
  • EP2428684B1 patent drawingFigure 2~3
  • EP2428684B1 patent drawingFigure 4~5

AI summary

Providing an impeller of a centrifugal compressor wherein the interference of the leakage vortex flow generated at the tip end side of the full blade with the leading edge of the splitter blade can be evaded and the high pressure ratio and the enhanced efficiency can be achieved. An impeller wherein a throat SR is formed so that a distance from a leading edge 5a of a rear side full blade 5R located on the rear side of the rotation direction of the compressor to a front side full blade 5F adjacent to the rear side full blade 5R and located on the front side of the rotation direction is minimized, and the leading edge of the splitter blade is placed in a fluid flow streaming along the flow passage between the mutually adjacent full blades, on the downstream side of a leakage vortex line WL formed to connect the middle location P of the throat to the leading edge 7a of the front side full blade 7.