Thermostructural Composite Rocket Propulsion Chamber Assembly

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Solution Overview

Problem

The existing rocket propulsion chambers face challenges in assembling metal combustion chambers with thermostructural composite material divergent parts due to differing coefficients of expansion, leading to complex mechanical connections and high manufacturing costs.

Innovation Solution

A propulsion chamber design featuring a single-piece thermostructural composite material envelope externally attached to the combustion chamber, with an external reinforcing casing to manage deformations, and a fixing system to immobilize the combustion chamber within the composite material casing, facilitating easier assembly and reducing weight and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a metal combustion chamber is connected to a divergent part made of thermostructural composite material, then the propulsion chamber can be constructed with appropriate material properties for different zones, but the assembly becomes complex due to different coefficients of expansion between metal and composite material

Engineering Contradiction:
Improvematerial suitability for different zonesVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the combustion chamber and divergent part into a single monobloc thermostructural composite component. This eliminates the interface between dissimilar materials (metal and composite), thereby removing the thermal expansion mismatch problem and simplifying the assembly while maintaining the ability to use appropriate material properties throughout the entire structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs thermostructural composite materials (such as carbon-silicon or carbon-carbon composites) for the entire propulsion chamber, including both the combustion chamber and divergent part. This allows the use of materials optimized for high-temperature and high-stress conditions throughout, while avoiding the complexity of joining dissimilar materials with different thermal expansion coefficients.

Inventive Principle:
Principle #40Composite materials

2Reliability

If a metal pressure-resistant casing with cooling circuit is used for the combustion chamber, then adequate cooling and pressure resistance are achieved, but the overall weight increases

Engineering Contradiction:
Improvepressure resistance and coolingVSAvoidpropulsion chamber weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent uses thermostructural composite materials (carbon-silicon or carbon-carbon) for the combustion chamber and cooling circuit, replacing traditional metal casings. These composite materials provide adequate strength and cooling capabilities while significantly reducing the weight of the propulsion chamber compared to metal constructions.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If the combustion chamber is inserted through an opening in the upper end of the envelope of thermostructural composite material, then the combustion chamber can be assembled, but the envelope requires complex opening and closing structures

Engineering Contradiction:
Improvecombustion chamber insertionVSAvoidenvelope structure complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

Instead of inserting the combustion chamber through an opening in the upper end of the envelope, the patent inverts the approach by inserting the combustion chamber through the divergent part. This eliminates the need for complex opening and closing structures in the envelope, simplifying both the envelope design and the assembly process.

Inventive Principle:
Principle #13The other way round (Inversion)

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 simplifies the assembly process, reduces weight, and provides structural integrity by managing pressure-induced deformations, resulting in a more efficient and cost-effective propulsion chamber.

Implementation Method 1

a metal combustion chamber, made of copper for example, the thickness of the wall of said combustion chamber comprising a cooling circuit in which one of the two propellants circulates

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

at least part of said casing of thermostructural composite material is covered with a reinforcing casing outer shell with high radial resistance to contain the deformations of the combustion chamber and of the said casing of thermostructural composite material

Methodology Applied
Scientific EffectMechanical reinforcement:

Data Source

PatentEP3058210B1Propulsion chamber for a rocket and method for producing such a chamber
Publication Date: 2020.02.19 ARIANEGRP SAS
  • EP3058210B1 patent drawingFigure 1
  • EP3058210B1 patent drawingFigure 2
  • EP3058210B1 patent drawingFigure 3~4

AI summary

The invention relates to a propulsion chamber (100) for a rocket and a method for producing such a propulsion chamber (100). The propulsion chamber (100) comprises a combustion chamber (12), one wall of the combustion chamber (12) comprising a cooling circuit (14) in which a first propellant (16) flows. According to the invention, an envelope made from a thermostructural composite material (24) is attached externally to said combustion chamber (12) and comprises a divergent portion (24c) extending beyond the lower end (12ee) of the combustion chamber (12) and at least a part of said envelope made from thermostructural composite material (24) is covered with an external reinforcement envelope (26) with high radial strength to contain deformations of the combustion chamber (12) and of said envelope made from thermostructural composite material (24), the envelope made from thermostructural composite material (24) and the external reinforcement envelope (26) forming a unitary assembly (28).