Diffuser Guide Vane Inlet Edge Angle Optimization

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Solution Overview

Problem

Current designs for impeller and diffuser blades in turbomachines lack a comprehensive technical theory to reliably improve aerodynamics, leading to inconsistent pressure loss reduction and flow efficiency.

Innovation Solution

The design features two-dimensional blade profiles with varying angles of attack and curvature, where the leading edge angle on the cover disk side is smaller than on the wheel disk side, and the guide vanes are inclined to optimize the flow transition from the impeller to the diffuser, reducing vortex formation and enhancing aerodynamic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional two-dimensional blade profiles are used in impeller and diffuser, then manufacturing is simple, but aerodynamic performance is insufficient with inconsistent pressure loss reduction

Engineering Contradiction:
Improvepressure lossVSAvoidblade profile complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent transitions from conventional two-dimensional blade profiles to three-dimensional blade profiles with varying angles of attack along the blade height. This dimensional change allows the blade geometry to better match the three-dimensional flow patterns in the impeller and diffuser, reducing flow separation and vortex formation while maintaining manufacturing feasibility through standardized profile stacks.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent applies different angles of attack at different blade height positions to optimize local flow conditions. The angle of attack varies along the blade height to match the local flow incidence angles, creating optimal aerodynamic conditions at each section of the blade while maintaining overall blade functionality.

Inventive Principle:
Principle #3Local quality

2Loss of energy

If guide vanes are arranged in an inclined shape with large circumferential spacing, then pressure loss may be reduced, but the effect is inconsistent and depends on specific aerodynamic boundary conditions

Engineering Contradiction:
Improvepressure lossVSAvoidaerodynamic performance consistency
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent systematically varies the angle of attack parameter along the blade height and across different blade positions to optimize aerodynamic performance. By changing geometric parameters in a controlled manner rather than using fixed inclined shapes, the design achieves consistent pressure loss reduction across different operating conditions and boundary conditions.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic adaptation to flow conditions by varying the blade profile characteristics along the height, allowing the blade to respond to changing flow angles and velocities at different radial positions. This dynamic geometric variation provides more reliable and consistent aerodynamic performance compared to static inclined arrangements.

Inventive Principle:
Principle #15Dynamics

3Reliability

If three-dimensional diffuser-guide vane designs are used downstream of open impeller, then flow patterns improve, but the design is not comparable to closed impeller conditions due to adhesion differences

Engineering Contradiction:
Improveflow pattern qualityVSAvoidapplicability to different impeller types
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent develops a universal three-dimensional blade profile design methodology that can be applied to both open and closed impeller configurations. By focusing on the fundamental flow physics and using scalable geometric parameters, the design achieves good flow patterns across different impeller types without requiring completely separate design approaches for each configuration.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 results in a significant improvement in aerodynamic performance by ensuring a loss-free flow into the diffuser and reducing pressure loss, achieving a harmonious, low-pressure flow pattern.

Implementation Method 1

a stationary diffuser located downstream of the impeller and equipped with guide vanes

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

ensuring a loss-free flow into the diffuser and reducing pressure loss

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3658780B1Throughflow assembly
Publication Date: 2024.06.26 SIEMENS ENERGY GLOBAL GMBH & CO KG
  • EP3658780B1 patent drawingFigure 1~2
  • EP3658780B1 patent drawingFigure 3
  • EP3658780B1 patent drawingFigure 4

AI summary

The invention relates to an arrangement (ARG), through which a process fluid (PFF) can flow along a main flow direction (MFD), comprising an impeller (IMP) that can rotate about an axis (X) in a rotation direction (RTD) and a stationary diffuser (DFF) located downstream of the impeller (IMP) and being provided with guide vanes (VNE), wherein the impeller (IMP) has an inlet (ILI) for a substantially axial inflow and an outlet (EXI) for a substantially radial outflow, wherein: radially and axially extending impeller vanes (BLD) are arranged between a wheel disc (HWI) and a cover disc (SWI) of the impeller (IMP), said vanes separating impeller channels (ICH) from one another in a circumferential direction (CDR); the diffuser (DFF) extends substantially radially along a main flow direction (MFD); the diffuser (DFF) has an axial cover disc side (SWS) and an axial wheel disc side (HWS) which delimit an axial channel width (SAC) of the diffuser (DFF) therebetween; the diffuser (DFF) has a diffuser inlet (IND) for a substantially radial inflow and a diffuser outlet (EXD); and guide vanes (VNE) extending axially along a vane vertical direction and radially along a through-flow direction are arranged between the wheel disc side (HWS) and the cover disc side (SWS) of the diffuser (DFF), said vanes separating the guide vane channels (HCN) from one another in a circumferential direction (CDR). According to the invention, an inlet edge angle (LEA) for each axial vane height is defined as an angle between an inlet edge tangent (TLV) on a mean line (BWL) on an inlet edge (DLE) of the respective guide vane (VNE) and a circumferential tangent (CTG) through the inlet edge, wherein the inlet edge angle (LEA) is smaller on the cover disc side than on the wheel disc side.