Plasma Channel Entrainment for Auto-Ignition Phasing Control

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Solution Overview

Problem

Conventional internal combustion engines face challenges in controlling combustion phasing and ignition efficiency due to geometric constraints and limitations in spark-discharge plasma channel placement, particularly in direct-injection controlled auto-ignition engines.

Innovation Solution

A powertrain system with a control module that generates a combustible charge and controls spark ignition to create a spark-discharge plasma channel, which is then moved by in-cylinder fuel injection to advance auto-ignition phasing, utilizing direct fuel injection and optimized valve timing to manipulate charge motion and plasma channel entrainment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional spark-ignition is used for combustion control in direct-injection controlled auto-ignition engines, then combustion phasing can be controlled, but geometric constraints limit the ability to locate the spark-discharge plasma channel at an ignitable region of the fuel-air mixture

Engineering Contradiction:

Improvecombustion phasing controlVSAvoidspark-discharge plasma channel placement flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the fuel injection timing and in-cylinder charge motion adjustable to dynamically position the spark-discharge plasma channel at the optimal location for ignition. The fuel injector is actuated at specific timings relative to piston position to create charge motion that entrains the plasma channel to the desired location, allowing adaptive control despite geometric constraints.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses in-cylinder charge motion as an intermediary to transfer the spark-discharge plasma channel from its fixed electrode location to the desired ignitable region. The charge motion, generated by fuel injection and valve timing, acts as a mediator that carries the plasma channel to the optimal position for auto-ignition.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If fuel injection timing is advanced to move plasma channel toward combustible charge, then auto-ignition phasing is advanced, but injection timing precision requirements increase

Engineering Contradiction:

Improvecombustion phasing advancementVSAvoidinjection timing precision

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent employs feedback by using sensors to detect piston position, in-cylinder pressure, and combustion characteristics, then adjusting the fuel injection timing and spark ignition timing based on this feedback to achieve the desired plasma channel positioning and combustion phasing while maintaining robust operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent changes multiple parameters including fuel injection timing, injection duration, spark ignition timing, and valve timing to collectively achieve plasma channel positioning. By adjusting multiple parameters in combination, the system achieves advanced combustion phasing while distributing the precision requirements across multiple controllable variables rather than relying solely on injection timing precision.

Inventive Principle:

Principle #35Parameter changes

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 method effectively advances combustion phasing, improving individual cylinder control during transients and relaxing geometric constraints, leading to more robust combustion system design and efficiency in controlled auto-ignition engines.

Implementation Method 1

code to control the spark ignition device to generate a spark-discharge plasma channel between cathode and anode electrodes of the spark ignition device

Methodology Applied

Scientific EffectSpark discharge: Electric Spark

Implementation Method 2

code to actuate the in-cylinder fuel injector to generate the combustible charge in the combustion chamber effective to move the spark-discharge plasma channel toward the combustible charge

Methodology Applied

Scientific EffectIn-cylinder charge motion: Convection

Data Source

PatentUS7643931B2Combustion control method for a direct-injection controlled auto-ignition combustion engine

Publication Date: 2010.01.05 GM GLOBAL TECHNOLOGY OPERATIONS LLC

AI summary

A powertrain and a control method therefore are provided wherein ignition of a combustible charge in a combustion chamber of a controlled auto-ignition internal combustion engine equipped with in-cylinder fuel-injection and a spark ignition device is controlled. A spark-discharge plasma channel is generated between the electrodes of the spark ignition device, and the combustible charge is ignited. The spark-discharge plasma channel is moved toward and entrained by the combustible charge, effective to advance phasing of controlled auto-ignition combustion.