Electrical Combustion Control via Microwave Actuation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Dynamic instabilities in combustion systems, such as those in gas turbine engines, are not effectively addressed by existing mechanical fuel actuation methods due to time lag and limited frequency range, leading to potential engine damage from self-amplifying acoustic and combustion oscillations.

Innovation Solution

A system comprising sensors, a controller, and an actuator that electrically modulates combustion by using microwaves, RF inductive coupling, or electromagnetic fields to counteract dynamic instabilities by adjusting the heat release rate and flame dynamics out of phase with detected oscillations, eliminating the need for mechanical actuation and its associated delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mechanical fuel actuation is used to counteract acoustic oscillations, then fuel flow can be regulated to combat dynamic instability, but time lag due to physical separation between flame and fuel nozzle limits effectiveness

Engineering Contradiction:

Improveeffectiveness of oscillation counteractionVSAvoidtime lag in fuel actuation

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces the mechanical fuel actuation system with an electrical actuation system using electrodes. Electrical signals can be transmitted instantaneously to the combustion zone without the physical transport delays inherent in mechanical fuel delivery systems, thereby eliminating the time lag between detection and counteraction while maintaining the ability to regulate fuel flow and combat dynamic instability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an electrical signal as an intermediary between the control system and the combustion zone. Instead of directly mechanically actuating fuel flow from a remote nozzle, electrical signals serve as a fast mediator that can instantly modulate combustion processes at the flame location, bridging the gap between detection and action without physical transport delays.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If mechanical fuel actuation is used to counteract acoustic oscillations, then fuel flow can be regulated, but the mechanical nature limits the frequency range or bandwidth

Engineering Contradiction:

Improveattenuation of oscillationsVSAvoidfrequency range of actuation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent substitutes electrical actuation for mechanical actuation to overcome frequency limitations. Electrical systems can respond to a much broader frequency range without the inertial and mechanical constraints that limit mechanical fuel actuation systems, enabling effective counteraction of oscillations across varying frequencies while maintaining reliable attenuation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of time

If electrical actuation is used to modulate combustion, then time lag is eliminated and frequency range is expanded, but new technology is required

Engineering Contradiction:

Improveresponse time of actuationVSAvoidcomplexity of electrical actuation system

Core Design Contradiction:

Loss of timeVSDevice complexity

Solution Approach 1:

The patent replaces the complex mechanical actuation infrastructure with a more streamlined electrical actuation system using electrodes. This substitution simplifies the overall system architecture by eliminating mechanical linkages, fuel delivery modifications, and associated mechanical components, while achieving superior response time and frequency performance through electrical signal modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

Effectively dampens combustion and acoustic oscillations, reducing the risk of engine damage by directly modulating heat release and flame dynamics to break the self-amplifying feedback loop, thereby enhancing stability and reducing the risk of catastrophic failure.

Implementation Method 1

The actuator is operated by the controller to provide electrical modulation of combustion within the combustion chamber

Methodology Applied

Scientific EffectMicrowave radiation: Microwave Radiation

Implementation Method 2

A system comprising sensors, a controller, and an actuator that electrically modulates combustion by using microwaves, RF inductive coupling, or electromagnetic fields

Methodology Applied

Scientific EffectRF inductive coupling: Electromagnetic Induction

Implementation Method 3

The controller uses input regarding conditions within the combustion chamber from the sensors to detect dynamic instabilities within the combustion chamber

Methodology Applied

Scientific EffectAcoustic oscillation detection: Acoustics

Implementation Method 4

The actuator is operated by the controller to provide electrical modulation of combustion within the combustion chamber such that the dynamic instabilities in the combustion chamber are counteracted

Methodology Applied

Scientific EffectElectromagnetic heating: Dielectric Heating

Data Source

PatentEP2844919B1Electrical control of combustion

Publication Date: 2018.10.17 UNITED TECH CORP

Figure 1A
Figure 1B
Figure 1C

AI summary

A system for electrically controlling combustion includes a combustion chamber, one or more sensors, an actuator, and a controller. The controller detects dynamic instabilities based upon input regarding conditions in the combustion chamber from the sensors. The actuator electrically modulates combustion, and the controller operates the actuator to counteract the dynamic instabilities.