Spacecraft Fuel Tank CFRP Polished Metallic Plating

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Solution Overview

Problem

Existing composite pressure containers for aerospace vehicles, particularly those storing helium, lack sufficient weight reduction and ignition resistance when storing liquid oxygen, as they do not adequately address the specific requirements of such environments.

Innovation Solution

A fuel tank for spacecraft comprising a carbon fiber reinforced plastic layer with a polished surface and a metallic plating layer, where the polishing is performed using a polishing instrument with a count of 200 to 2000, and the metallic plating layer is strategically placed on the inner or outer surface to enhance ignition resistance in a liquid oxygen ambiance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If a composite pressure container is used to reduce weight, then the weight of the pressure container is reduced, but the resistance to ignition in liquid oxygen ambience is insufficient

Engineering Contradiction:
Improveweight of pressure containerVSAvoidignition resistance in liquid oxygen
Core Design Contradiction:
Weight of moving objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies composite materials by combining carbon fiber reinforced plastic (CFRP) with metallic plating layers. The CFRP provides lightweight structural strength while the metallic plating (such as aluminum or other ignition-resistant metals) provides protection against ignition in liquid oxygen environments. This composite structure resolves the contradiction by integrating the weight-saving benefits of composites with the safety requirements for liquid oxygen storage.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies local quality by selectively applying metallic plating only to the inner surface of the CFRP that contacts liquid oxygen. This localized treatment provides ignition resistance where it is most needed (at the fuel interface) while maintaining the lightweight properties of the CFRP in other areas. The polishing of the inner surface also represents a local quality approach, specifically treating the surface that contacts liquid oxygen to prevent ignition.

Inventive Principle:
Principle #3Local quality

2Weight of moving object

If the thickness of metal layer is reduced to reduce weight, then the weight is reduced, but the manufacturing precision and surface quality require improvement

Engineering Contradiction:
Improveweight of pressure containerVSAvoidsurface quality of inner layer
Core Design Contradiction:
Weight of moving objectVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by specifying a polishing count range of 200 to 2000 for the inner surface of the CFRP. This quantitative parameter control ensures the surface achieves the appropriate roughness or smoothness level needed for metallic plating adhesion and ignition resistance, while maintaining thin metal layer thickness for weight reduction. The polished surface morphology is controlled within specific parameters to optimize both weight and surface quality.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3398858B1Spacecraft fuel tank and manufacturing method therefor
Publication Date: 2022.03.30 KAWASAKI JUKOGYO KK
  • EP3398858B1 patent drawingFigure 1
  • EP3398858B1 patent drawingFigure 2
  • EP3398858B1 patent drawingFigure 3

AI summary

A fuel tank for use with a spacecraft, the fuel tank being configured to store therein fuel for driving the spacecraft, comprises a carbon fiber reinforced plastic layer (101) and a metallic plating layer (102), the carbon fiber reinforced plastic layer (101) has a polished surface (101A) having been subjected to polishing processing, the polished surface being on an inner side of the fuel tank (100), and the metallic plating layer (102) is provided on the polished surface.