Regeneratively Cooled Nozzle Form-Fit Connection

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Solution Overview

Problem

Existing methods for producing regeneratively cooled nozzle extensions for rocket combustion chambers are complex and costly due to the use of soldering and welding processes, which limit cooling efficiency and increase production complexity.

Innovation Solution

A method involving a form fit connection between coaxially arranged first and second walls, where cooling channel webs of the first wall engage corresponding depressions on the second wall, achieved through reshaping the second wall using mechanical processing steps, eliminating the need for soldering and welding, and allowing for efficient production of regeneratively cooled nozzle extensions with high cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If soldering and welding processes are used to connect walls, then structural strength is improved, but production complexity and cost increase

Engineering Contradiction:
Improvestructural strengthVSAvoidproduction complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The nozzle extension is divided into multiple segments (first wall, second wall, intermediate walls) that are connected through form-fit interfaces. Each segment can be manufactured separately using mechanical processing, avoiding complex welding while maintaining structural integrity through the interlocking geometry of cooling channel webs and corresponding recesses.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces thermal joining processes (soldering and welding) with mechanical form-fit connections. The cooling channel webs of one wall engage with corresponding recesses in adjacent walls through precise mechanical shaping, eliminating the need for thermal processes and associated complexity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Length of stationary object

If cooling channels have small cross-section, then wall thickness is reduced, but cooling capacity is limited

Engineering Contradiction:
Improvewall thicknessVSAvoidcooling capacity
Core Design Contradiction:
Length of stationary objectVSReliability

Solution Approach 1:

The patent transitions from small cross-sectional cooling channels to cooling channels with extended surface area through the form-fit connection geometry. The cooling channel webs create a three-dimensional heat dissipation structure that increases the effective cooling surface area without requiring thicker walls, thereby improving cooling capacity while maintaining wall thickness constraints.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Shape

If multiple profile elements are welded together, then cooling channel geometry is achieved, but production process becomes complex

Engineering Contradiction:
Improvecooling channel geometryVSAvoidproduction process complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent merges the cooling channel geometry creation with the wall structure itself. The cooling channel webs are integrated into the wall design and connected through form-fit interfaces, eliminating the need to assemble multiple separate profile elements. This integration simplifies the production process while maintaining the required cooling channel geometry.

Inventive Principle:
Principle #5Merging (Combining)

4Ease of manufacture

If form fit connection is used without reshaping, then production is simpler, but connection reliability is insufficient

Engineering Contradiction:
Improveproduction simplicityVSAvoidconnection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent incorporates reshaping of the second wall as a preliminary action during manufacturing. The second wall is pre-shaped with recesses that precisely match the cooling channel webs of adjacent walls, ensuring reliable form-fit connections are achieved during assembly. This preliminary shaping action ensures connection reliability while maintaining overall production simplicity.

Inventive Principle:
Principle #10Preliminary action

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 simplifies the production of regeneratively cooled nozzle extensions, reduces production costs, and ensures high cooling efficiency by avoiding complex welding processes while allowing for flexible shaping of cooling channels and increased rigidity through the use of stiffening rings.

Implementation Method 1

cooling channels through which at least one fuel component flows in order to extract heat from the wall of the nozzle extension

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the first and the second wall are connected to one another by a form fit, in that cooling channel webs of the first wall engage in corresponding depressions of the second wall to form the form fit

Methodology Applied
Scientific EffectMechanical interlocking: Mechanical Fastener

Data Source

PatentEP2354518B1Method of manufacturing a regeneratively cooled divergent nozzle of a rocket combustion chamber and nozzle
Publication Date: 2014.11.05 AIRBUS DS GMBH
  • EP2354518B1 patent drawingFigure 1
  • EP2354518B1 patent drawingFigure 2
  • EP2354518B1 patent drawingFigure 3

AI summary

The invention describes a method for manufacturing a regeneratively cooled nozzle extension for a rocket combustion chamber, comprising a first wall (1) and a second wall (2) arranged coaxially and between which a number of cooling channels (11) are formed, laterally bounded by cooling channel webs (5, 10). The first and second walls (1, 2) are connected to each other by a positive fit (7) in that cooling channel webs (5, 10) of the first wall (1) engage in corresponding recesses (6) of the second wall (2) to form the positive fit (7). The positive fit (7) is produced by deforming the second wall (2), which has the recesses, in the area of ​​the cooling channels (11).