Diffuser Pipe Transition Geometry for Aircraft Compressor Flow Losses

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Solution Overview

Problem

Existing diffuser pipe configurations in gas turbine engines for aircraft propulsion systems do not effectively manage fluid flow, leading to inefficiencies and losses.

Innovation Solution

The diffuser pipe design features a transition body portion with diverging and converging sub-portions that monotonically change the cross-sectional area to decelerate and accelerate fluid flow, reducing losses and improving homogeneity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a conventional diffuser pipe configuration is used, then the structure is simple, but fluid flow homogeneity deteriorates and losses increase

Engineering Contradiction:
Improvefluid flow lossesVSAvoiddiffuser pipe structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The diffuser pipe is segmented into three distinct portions: an inlet body portion, a transition body portion, and an outlet body portion. The transition body portion is further divided into a diverging sub-portion and a converging sub-portion. This segmentation allows each portion to perform a specific function in managing fluid flow, reducing losses through controlled area changes while maintaining manageable structural complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The diffuser pipe employs curved transitions instead of sharp angles or straight lines. The transition body portion features smooth diverging and converging curves that monotonically change the cross-sectional area. These curved geometries reduce flow separation and turbulence, minimizing energy losses while creating a more complex but functional structure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Loss of energy

If the cross-sectional area changes abruptly, then the structure is simple, but fluid flow homogeneity deteriorates

Engineering Contradiction:
Improvefluid flow lossesVSAvoidcross-sectional area control
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent systematically changes the cross-sectional area parameter along the length of the diffuser pipe. The transition body portion monotonically increases the area in the diverging sub-portion and then monotonically decreases it in the converging sub-portion. This controlled parameter change optimizes fluid flow homogeneity and reduces losses, requiring precise manufacturing but achieving superior flow characteristics.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Smooth curved transitions are used instead of abrupt area changes. The diverging and converging sub-portions feature continuous curvature that monotonically adjusts the cross-sectional area, preventing flow separation and turbulence. This curved geometry approach requires high manufacturing precision but delivers significant reductions in fluid flow losses.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Loss of energy

If a transition body portion with diverging and converging sub-portions is added, then fluid flow homogeneity improves, but device complexity increases

Engineering Contradiction:
Improvefluid flow lossesVSAvoiddiffuser pipe structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The diffuser pipe is divided into functional segments: an inlet body portion, a transition body portion with diverging and converving sub-portions, and an outlet body portion. This segmentation allows the transition portion to specifically address flow homogeneity and loss reduction, while the inlet and outlet portions maintain simpler structures for connection purposes, balancing overall device complexity with performance improvement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The transition body portion serves multiple functions: it diffuses the fluid flow, controls cross-sectional area changes, and improves flow homogeneity. By consolidating these functions into a single integrated component with diverging and converging sub-portions, the design achieves improved fluid flow characteristics without proportionally increasing overall device complexity.

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 design enhances fluid flow homogeneity and reduces losses, contributing to improved combustion and efficiency in gas turbine engines.

Implementation Method 1

Diffuser pipes are provided in certain gas turbine engines for diffusing fluid flow (e.g., air flow) received from an impeller of a centrifugal compressor

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

The cross-sectional area monotonically increases in the diverging sub-portion in a direction from the passage inlet to the passage outlet. The cross-sectional area monotonically decreases in the converging sub-portion

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP4600465A1Diffuser pipe for an aircraft propulsion system
Publication Date: 2025.08.13 PRATT & WHITNEY CANADA CORP
  • EP4600465A1 patent drawingFigure 1
  • EP4600465A1 patent drawingFigure 2
  • EP4600465A1 patent drawingFigure 3

AI summary

A compressor diffuser (33) for an aircraft propulsion system includes a plurality of diffuser pipes (200). Each diffuser pipe (200) includes a pipe body (202). The pipe body (202) extends between and to an inlet end (204) and an outlet end (206). The pipe body (202) includes a suction lateral wall (214) and a pressure lateral wall (216). The pipe body (202) further includes a transition body portion (224). The suction lateral wall (214) and the pressure lateral wall (216) extend between and to the inlet end (204) and the outlet end (206) to form a fluid passage (208). The fluid passage (208) extends along a center position from a passage inlet (210) at the inlet end (204) to a passage outlet (212) at the outlet end (206). The fluid passage (208) has a cross-sectional area (A). The transition body portion (224) is disposed at the outlet end (206). The transition body portion (224) includes a diverging sub-portion (224A) and a converging sub-portion (224B). The cross-sectional area (A) increases in the diverging sub-portion (224A). The cross-sectional area (A) decreases in the converging sub-portion (224B).