Rocket Ignition System Continuous Flow Homogeneity

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Solution Overview

Problem

In liquid propellant rocket engines, the ignition system is only operational during the initial ignition phase, leading to inefficiencies and safety concerns due to hot gases rising in the igniter channel, which can freeze and block propellant entry, preventing re-ignition, and requires additional neutral gases for purging, impacting performance and safety.

Innovation Solution

The ignition system is integrated into the injection head and comprises a main, secondary, and tertiary ignition channel, allowing for continuous operation during the injection phase, scavenging hot gases with oxidizer and providing a homogeneous fuel and oxidizer flow, eliminating the need for neutral purge gases and enhancing combustion efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the ignition system operates only during the initial ignition phase, then the system complexity is reduced, but hot gases rise in the igniter channel and freeze, blocking propellant entry and preventing re-ignition

Engineering Contradiction:
Improveignition system operation durationVSAvoidre-ignition capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The ignition system is designed to operate continuously during both the ignition phase and the stabilized injection phase, rather than shutting down after initial ignition. This continuous operation prevents hot gases from rising and freezing in the igniter channel, maintaining reliable re-ignition capability throughout the engine's operation.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The ignition system maintains readiness by continuing to supply igniter propellants during the stabilized phase, preparing in advance for any potential re-ignition needs. This preliminary maintenance of operational state prevents the harmful freezing effect that would occur if the system shut down completely.

Inventive Principle:
Principle #10Preliminary action

2Loss of substance

If the ignition system is shut down during the stabilized injection phase, then propellant consumption is reduced, but additional neutral gases are required for purging, impacting performance

Engineering Contradiction:
Improvepropellant consumptionVSAvoidrocket performance
Core Design Contradiction:
Loss of substanceVSProductivity

Solution Approach 1:

The ignition system uses its own propellant supply during the stabilized phase to maintain operation and prevent hot gas rise, rather than requiring external neutral purge gases. This self-service approach eliminates the need for separate purging systems and maintains performance by using combustion-supporting propellants instead of inert gases.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of shutting down the ignition system and dealing with the harmful effect of hot gas freezing, the system converts this potential harm into a benefit by maintaining continuous operation. The continuous flow of igniter propellants prevents freezing and blocks hot gas rise, turning what would be a wasted resource into a protective function that enhances reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If the ignition system operates continuously during the injection phase, then combustion efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvecombustion efficiencyVSAvoidignition system structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The ignition system is integrated with the main propellant supply system, merging the igniter propellant supply with the main oxidizer and fuel supply lines. This integration allows continuous operation during the stabilized phase without requiring entirely separate systems, thereby improving combustion efficiency while limiting the increase in overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

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 configuration improves combustion efficiency by utilizing additional oxidizer and fuel during the stabilized phase, prevents hot gases from rising in the igniter channel, and eliminates the need for neutral purge gases, enhancing overall rocket performance and safety.

Implementation Method 1

a spark plug 107 for igniting the oxidizer and fuel mixture

Methodology Applied
Scientific EffectElectrical discharge ignition: Electric Spark

Implementation Method 2

where the combustion as such takes place

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 3

a combustion chamber body 6 (where the combustion as such takes place) cooled by a cooling circuit 6bis

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3147490B1Propulsion system of a rocket
Publication Date: 2019.05.01 CENT NAT DETUD SPATIALES (CNES)
  • EP3147490B1 patent drawingFigure 1
  • EP3147490B1 patent drawingFigure 2
  • EP3147490B1 patent drawingFigure 3~4

AI summary

The invention relates to a rocket propulsion system comprising: an oxidizer supply system (2); a fuel supply system (3); a combustion chamber (6); a plurality of injectors (101); an ignition system (40); the injectors (101) and the ignition system (40) being in communication with the oxidizer supply system and the fuel supply system and opening into the combustion chamber (6), the injectors (101) being configured to, during an injection phase, bring oxidizer and fuel to the combustion chamber (6);the ignition system (40) being configured to, during an ignition phase, bring hot gases to the combustion chamber (6) and to, during the injection phase, bring oxidizer and fuel to the combustion chamber (6) in such a way that the flow rate of oxidizer and fuel from the ignition system (40) is homogeneous with that from the injectors (101).