Rocket Injector Flow Splitter Segmentation

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Solution Overview

Problem

Existing coaxial injector elements for rocket drives suffer from oxidant infiltration into the propellant distribution space due to capillary effects, leading to unwanted reactions between propellants.

Innovation Solution

The injector element features a flow splitter with annular rings forming sharp circumferential edges between the central body and sleeve, preventing oxidant migration by eliminating unbroken surfaces within the flow splitter slots, thereby enhancing the reliability of the injector and rocket drive.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a flow divider with slots is used to split the fuel flow, then the fuel is divided into multiple individual flows, but oxidant infiltrates into the propellant distribution space through capillary effects

Engineering Contradiction:
Improvefuel flow splitting efficiencyVSAvoidpropellant separation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The flow splitter is segmented into multiple discrete annular rings instead of being a continuous structure. The slots are formed between these separated rings, creating sharp circumferential edges that break capillary continuity. This segmentation maintains fuel flow splitting functionality while preventing oxidant infiltration through the broken capillary paths.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention introduces a new dimensional feature - sharp circumferential edges at the slot openings formed by the annular rings. These edges create a geometric discontinuity in the capillary path that prevents oxidant migration. The edges add a circumferential dimension to the slot geometry that blocks the radial capillary infiltration path.

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

2Ease of manufacture

If the flow splitter slots have unbroken surfaces, then the manufacturing is simpler, but capillary effects allow oxidant migration into the propellant distribution space

Engineering Contradiction:
Improveflow splitter manufacturing simplicityVSAvoidoxidant infiltration
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The flow splitter is divided into multiple annular rings with gaps between them, segmenting the previously continuous surface. This segmentation creates sharp circumferential edges that disrupt capillary action while maintaining manufacturing feasibility through standard machining or molding processes.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The slot geometry is made asymmetric by introducing sharp circumferential edges through the annular ring configuration. The slots have different surface characteristics at different locations - smooth inner surfaces for fuel flow but sharp edges at the circumferential openings to prevent oxidant infiltration.

Inventive Principle:
Principle #4Asymmetry

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 effectively prevents oxidant migration, ensuring reliable operation by avoiding unwanted propellant reactions outside the combustion chamber, thereby increasing the reliability of the injector and rocket engine performance.

Implementation Method 1

oxidant may infiltrate from the combustion chamber through the flow divider into a distribution space of the propellant due to capillary effects

Methodology Applied
Scientific EffectCapillary effects: Capillary Action

Data Source

PatentEP2757243B1Injector element
Publication Date: 2015.08.12 AIRBUS DS GMBH
  • EP2757243B1 patent drawingFigure 1
  • EP2757243B1 patent drawingFigure 2~3
  • EP2757243B1 patent drawingFigure 4

AI summary

An injector element (1) of coaxial design is provided for a rocket drive for operation with a first and a second propellant, comprising a central body (5), a sleeve (2) and a flow splitter (7). The central body (5) comprises a flow channel with an outlet, the central body (5) generating a conical drop distribution at the outlet forming a fuel cone, wherein the first propellant, normally an oxidant, is provided in the central body (5). The sleeve (2) concentrically surrounds the central body (5) to form an annular flow channel for the second propellant, normally fuel. The flow splitter (7) is arranged between the central body (5) and the sleeve (2) for splitting the second propellant into a plurality of individual flows. The flow splitter (7) includes a given number of passage channels which are distributed around the central body (5), each of the passage channels for generating a fine propellant jet. The passage channels are formed between annular rings (18, 19) extending towards each other to provide sharp circumferential edges to the passage channels, a first of the rings (18, 19) being part of the central body (5) and a second of the rings (18, 19) being part of the sleeve (2), wherein one of the first and the second annular rings (18, 19) having protrusions (20, 21) which are distributed around the central body (5) and adjoin to the other annular ring.