Aircraft Compressor Diffuser Pipe Geometry for Lower Flow Loss
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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
A diffuser pipe design featuring a transition body portion with diverging and converging sub-portions that monotonically change cross-sectional area and length to facilitate deceleration and acceleration of fluid flow, reducing flow losses and enhancing homogeneity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional diffuser pipe configurations are used, then the structure is simple, but fluid flow management is ineffective leading to losses
Solution Approach 1:
The diffuser pipe is divided into multiple functional sections: inlet body portion with monotonically increasing cross-sectional area, transition body portion with diverging sub-portion, and converging sub-portion. Each section performs a specific flow management function, reducing energy losses through staged area changes rather than a single simple configuration.
Solution Approach 2:
The diffuser pipe employs dynamic area changes along the flow path - the cross-sectional area monotonically increases in the inlet body portion, then diverges in the diverging sub-portion, and finally converges in the converging sub-portion. These dynamic geometric transformations optimize fluid flow at different stages, reducing turbulence and energy losses compared to static simple configurations.
2Stability of the object's composition
If the cross-sectional area changes monotonically in the inlet body portion, then fluid flow homogeneity is improved, but the passage length increases
Solution Approach 1:
The monotonically increasing cross-sectional area in the inlet body portion is applied partially - only in the initial section before the transition body portion. This partial application achieves sufficient flow homogeneity improvement without extending the overall passage length excessively, as the transition body portion then compacts the flow path through diverging and converging sub-portions.
Solution Approach 2:
Instead of achieving flow homogeneity solely through extended passage length in one dimension, the invention uses cross-sectional area changes in another dimension (the radial dimension). The monotonically increasing area in the inlet body portion and subsequent diverging/converging sections create homogeneity through geometric transformation rather than simply lengthening the flow path.
3Speed
If the transition body portion forms a turn with inner and outer walls, then flow direction is changed, but flow separation may occur
Solution Approach 1:
The transition body portion uses curved surfaces to form the turn - the suction lateral wall forms a smooth inner wall curvature while the pressure lateral wall forms an outer wall curvature. These curved geometries guide flow through the turn more smoothly compared to sharp angular transitions, reducing flow separation and energy losses during direction change.
Solution Approach 2:
The transition body portion changes geometric parameters along the flow path - the cross-sectional area diverges then converges, and the wall curvatures are specifically designed with different radii of curvature for the inner and outer walls. These parameter changes optimize the turn geometry to maintain attached flow and minimize separation losses while achieving the required flow direction change.
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
The design improves fluid flow homogeneity and reduces losses, contributing to better combustion and efficiency in gas turbine engines.
Implementation Method 1
The cross-sectional area monotonically increases in the diverging sub-portion in a direction from the passage inlet to the passage outlet
Implementation Method 2
The cross-sectional area monotonically decreases in the converging sub-portion in the direction from the passage inlet to the passage outlet
Data Source
AI summary
A compressor diffuser for an aircraft propulsion system includes a plurality of diffuser pipes. Each diffuser pipe includes a pipe body. The pipe body extends between and to an inlet end and an outlet end. The pipe body includes a suction lateral wall and a pressure lateral wall. The pipe body further includes a transition body portion. The suction lateral wall and the pressure lateral wall extend between and to the inlet end and the outlet end to form a fluid passage. The fluid passage extends along a center position from a passage inlet at the inlet end to a passage outlet at the outlet end. The fluid passage has a cross-sectional area. The transition body portion is disposed at the outlet end. The transition body portion includes a diverging sub-portion and a converging sub-portion. The cross-sectional area increases in the diverging sub-portion. The cross-sectional area decreases in the converging sub-portion.