Dimpled Combustion Liner for Flame Scrubbing Reduction

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Gas turbine engine combustors experience distress and wear due to flame scrubbing caused by high-temperature combustion products, which leads to thermal gradients and liner failure, necessitating a solution to reduce flame interaction with the combustion liner.

Innovation Solution

The design incorporates a combustion liner with dimples and protrusions that alter the thermal gradient and exit temperature profile, reducing flame scrubbing by moving the inner surface away from hot gases and optimizing the combustion chamber's volume and residence time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the combustion liner surface is moved away from hot gases using dimples and protrusions, then flame scrubbing is reduced and liner life is enhanced, but the device complexity increases

Engineering Contradiction:

Improvecombustion liner lifeVSAvoidcombustion liner structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The combustion liner incorporates dimples (concave curved surfaces) and protrusions (convex curved surfaces) instead of flat surfaces. These curved geometric features alter the flow path of hot gases, creating zones that redirect flames away from the liner surface, thereby reducing flame scrubbing and thermal gradients while extending liner life.

Inventive Principle:

Principle #14Spheroidality (Curvature)

Solution Approach 2:

The dimples and protrusions create localized regions with different flow characteristics. Specifically, the dimples generate recirculation zones that trap hot gases away from the liner, while protrusions create shock waves that redirect flow. This local modification of flow quality reduces thermal stress at critical locations without requiring complete redesign of the entire combustor.

Inventive Principle:

Principle #3Local quality

2Productivity

If dimples and protrusions are added to alter thermal gradient and exit temperature profile, then combustion efficiency is improved and NOx emissions are reduced, but manufacturing complexity increases

Engineering Contradiction:

Improvecombustion efficiencyVSAvoidcombustion liner fabrication

Core Design Contradiction:

ProductivityVSEase of manufacture

Solution Approach 1:

The invention modifies the geometric parameters of the combustion liner by introducing dimples with specific depth-to-diameter ratios and protrusions with controlled heights. These parameter changes create optimal flow patterns that enhance combustion efficiency and reduce NOx emissions. The parameters can be adjusted during design to balance performance with manufacturing capabilities.

Inventive Principle:

Principle #35Parameter changes

3Loss of time

If the combustion chamber volume is optimized with dimples, then residence time is increased and complete combustion is promoted, but the volume of the liner increases

Engineering Contradiction:

Improveresidence timeVSAvoidcombustion liner volume

Core Design Contradiction:

Loss of timeVSVolume of stationary object

Solution Approach 1:

The dimples are formed as recesses within the existing combustion liner structure, effectively nesting additional volume within the original outer boundaries. This allows the creation of recirculation zones and extended residence time regions without significantly increasing the overall external dimensions of the combustion liner, thus minimizing the impact on engine integration.

Inventive Principle:

Principle #7Nested doll (Nesting)

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 the life of combustion liners, improves engine operability, and promotes complete combustion, reducing NOx emissions and increasing the engine's relight performance at high altitudes.

Implementation Method 1

Methodology Applied

Scientific EffectThermal gradient: Temperature Gradient

Implementation Method 2

This design enhances the life of combustion liners, improves engine operability, and promotes complete combustion, reducing NOx emissions

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS11994291B2Performance factor for a combustion liner

Publication Date: 2024.05.28 GENERAL ELECTRIC CO

AI summary

An annular combustor includes a combustion liner defining a combustion chamber, the combustion liner having an outer liner and an inner liner and a plurality of dimples in the combustion liner. The combustion liner is characterized by a performance factor greater than or equal to one and less than or equal to seven. An engine includes the annular combustor.