Deflector Deformations for Uniform Cooling in Combustion Chambers

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Solution Overview

Problem

In annular turbomachine combustion chambers with inclined transverse walls, the non-uniform cooling of deflectors due to varying distances between the wall and deflectors leads to uneven heat distribution and premature deterioration, reducing the service life of the chamber.

Innovation Solution

A frustoconical transverse wall with radially guiding deformations, such as grooves, is implemented to force cooling air to flow uniformly around fuel injection systems, ensuring homogeneous cooling across the deflectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the transverse wall is inclined relative to the longitudinal axis, then the chamber can accommodate the injection systems with appropriate clearance, but the distance between the wall and deflectors becomes non-uniform, leading to non-homogeneous cooling

Engineering Contradiction:
Improveclearance for injection systemsVSAvoidcooling homogeneity
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The deflector is equipped with flow-guiding means (such as radially extending baffles or grooves) that create different flow paths in different regions of the deflector. This local structural variation ensures that cooling air is distributed uniformly across the entire deflector surface, compensating for the non-uniform gap caused by the inclined wall configuration.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If the transverse wall is perpendicular to the longitudinal axis, then the distance to deflectors is constant, but the injection systems may not have adequate clearance from the wall

Engineering Contradiction:
Improvecooling homogeneityVSAvoidclearance for injection systems
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

Instead of changing the global wall orientation, the invention introduces local flow-guiding structures on the deflector surface. These structures (baffles or grooves) are positioned to redirect cooling air flow radially outward, ensuring uniform cooling distribution while maintaining the perpendicular wall configuration that provides adequate clearance for injection systems.

Inventive Principle:
Principle #3Local quality

3Temperature

If multiperforation holes are drilled facing the deflectors, then cooling air can reach the deflectors, but without flow guidance the cooling is non-uniform and deflectors deteriorate prematurely

Engineering Contradiction:
Improvecooling air deliveryVSAvoiddeflector service life
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The flow-guiding means (radial baffles or grooves) are integrated into the deflector structure to locally redirect the cooling air flow. This creates different flow distribution zones that collectively achieve uniform cooling across the entire deflector surface, preventing localized overheating and extending service life.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The flow-guiding structures act as intermediary elements between the multiperforation holes and the deflector surface. They mediate the cooling air flow, transforming the direct but non-uniform flow from the holes into a uniformly distributed flow pattern across the deflector, thereby protecting the deflector from premature deterioration.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enhances the cooling homogeneity and extends the service life of the combustion chamber by maintaining consistent cooling across the deflectors, preventing premature deterioration.

Implementation Method 1

a plurality of multiperforation holes formed opposite the deflectors around their opening for allow a passage of air intended for the cooling of said baffles

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP1818617B1Transverse wall of a combustion chamber equipped with multi-perforation holes
Publication Date: 2012.08.29 SN DETUDE & DE CONSTR DE MOTEURS DAVIATION (S N E C M A)
  • EP1818617B1 patent drawingFigure 1
  • EP1818617B1 patent drawingFigure 2~3
  • EP1818617B1 patent drawingFigure 4~6

AI summary

The wall has a set of deflectors (16) forming a heat shield and mounted in each of a set of apertures (12). The deflectors has a circular aperture (17) centered on an axis of symmetry of fluid injection systems (14). Each deflector comprises two deformations (20) forming chicanes for through-flow of a cooling air flow. The deformations force the flow of cooling air for the deflectors to flow radially around the fuel injection systems. The deformations extend radially on both sides of the circular aperture to allow passage of the fuel injection systems.