Turbomachine Combustion Chamber Deflector for Ignition Plug Wake

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Solution Overview

Problem

The presence of a wake induced by the ignition plug in turbomachine combustion chambers disrupts the efficiency of the cooling system, leading to a pressure drop and reduced airflow through micro-perforations, which shortens the lifetime of the annular wall and increases the risk of bushing disengagement.

Innovation Solution

Incorporating deflection means, such as ducts or deflecting walls, to divert airflow towards the median plane of the wake, increasing the total pressure and pressure difference between the wake and the combustion chamber, thereby enhancing convective transfer through micro-perforations and reducing the risk of cracks and bushing disengagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an ignition plug is installed in the combustion chamber, then combustion initiation is enabled, but a wake is created that disrupts cooling airflow and reduces pressure

Engineering Contradiction:

Improvecombustion initiationVSAvoidpressure drop in wake region

Core Design Contradiction:

ReliabilityVSStress or pressure

Solution Approach 1:

The patent applies preliminary anti-action by introducing deflection means (ducts or walls) that preemptively redirect the bypass airflow before it enters the wake region. This preliminary redirection prevents the airflow from being disrupted by the ignition plug wake, thereby maintaining pressure and cooling efficiency despite the presence of the ignition plug

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent uses deflection means as an intermediary element between the bypass airflow and the ignition plug wake. These ducts or walls act as mediators that guide the airflow around the wake region, preventing direct interaction between the cooling airflow and the low-pressure wake zone created by the ignition plug

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If bypass airflow is used for cooling the annular wall, then cooling efficiency is improved, but the wake created by the ignition plug disrupts this airflow

Engineering Contradiction:

Improvecooling efficiency of annular wallVSAvoidairflow throughput through micro-perforations

Core Design Contradiction:

TemperatureVSProductivity

Solution Approach 1:

The deflection means preemptively redirect the bypass airflow before it encounters the wake region, preventing disruption to the cooling flow. This ensures that the airflow maintains its cooling efficiency and continues to flow effectively through the micro-perforations in the annular wall

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The patent applies local quality by creating a specialized flow path through the deflection means that specifically addresses the wake region. The ducts or walls are positioned and shaped to locally redirect airflow in the critical wake zone, while leaving other regions of the cooling system unchanged

Inventive Principle:

Principle #3Local quality

3Duration of action of stationary object

If the wake region has reduced pressure, then airflow through micro-perforations decreases, but this leads to reduced cooling and shorter component lifetime

Engineering Contradiction:

Improvelifetime of annular wallVSAvoidairflow quantity through micro-perforations

Core Design Contradiction:

Duration of action of stationary objectVSQuantity of substance

Solution Approach 1:

The deflection means preemptively redirect the bypass airflow to avoid the wake region, preventing the pressure drop that would otherwise reduce airflow through the micro-perforations. This maintains adequate cooling flow to ensure the longevity of the annular wall

Inventive Principle:

Principle #9Preliminary anti-action

Solution Approach 2:

The deflection means serve as an intermediary that protects the micro-perforation cooling system from the harmful effects of the wake region. By redirecting airflow around the wake, the deflection means preserve the pressure differential needed for effective cooling through the micro-perforations

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

The solution improves the cooling efficiency of the annular wall, extends its lifetime, and reduces the risk of bushing disengagement by increasing air pressure within the wake, leading to more effective convective heat transfer and reduced metal loss.

Implementation Method 1

increasing the total pressure and pressure difference between the wake and the combustion chamber

Methodology Applied

Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 2

enhancing convective transfer through micro-perforations

Methodology Applied

Scientific EffectConvection: Convection

Data Source

PatentUS10233836B2Turbomachine combustion chamber provided with air deflection means for reducing the wake created by an ignition plug

Publication Date: 2019.03.19 SAFRAN AIRCRAFT ENGINES SAS

AI summary

A device for cooling of an annular wall of a turbomachine combustion chamber provided with micro-perforations, and in particular the cooling of a region of the wall facing a wake induced by an ignition plug, the device includes, a deflector designed to divert air immersing the ignition plug towards a median plane of the wake and towards the annular wall of the combustion chamber, so as to increase the air pressure within the wake in proximity to the annular wall.