Flexible Net Damping Liquid Hydrogen Sloshing in Spacecraft Tanks

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Solution Overview

Problem

Current systems for damping propellants in spacecraft tanks, particularly liquid hydrogen, are ineffective in preventing vaporization due to sloshing movements, leading to performance losses and increased weight, despite attempts to minimize contact with hot zones.

Innovation Solution

A fluid damping device comprising a net on a rigid frame with adjustable rods and rings, made of aluminum and polymer materials, that dampens sloshing movements without generating splashes, and can be configured to adapt to different fluid viscosities and spacecraft tank designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If current systems are used to minimize contact between liquid hydrogen and hot tank areas, then vaporization losses are reduced, but the device complexity and weight increase significantly

Engineering Contradiction:
Improveliquid hydrogen vaporization lossVSAvoiddamping system complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The patent employs a flexible net made of thin polymer or metallic wires instead of complex rigid structures. This net is arranged within the tank to dampen liquid hydrogen sloshing movements, reducing contact with hot areas. The flexibility and simplicity of the net structure avoid the complexity and weight penalties of conventional rigid damping systems while effectively minimizing vaporization losses.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The damping net functions as a porous structure with interconnected wires forming open spaces. This porous configuration allows the liquid hydrogen to pass through while the net structure dissipates kinetic energy and reduces sloshing intensity, thereby decreasing contact between the propellant and hot tank areas without requiring complex sealed systems.

Inventive Principle:
Principle #31Porous materials

2Object-generated harmful factors

If a rigid frame with mesh is used to dampen fluid movements, then sloshing is reduced, but the device weight increases

Engineering Contradiction:
Improvefluid sloshing movementVSAvoiddamping device weight
Core Design Contradiction:
Object-generated harmful factorsVSWeight of moving object

Solution Approach 1:

Instead of heavy rigid frames, the patent uses a flexible net constructed from thin wires or polymer strands. This flexible structure achieves sloshing dampening through its ability to deform and interact with the moving liquid, significantly reducing the device weight while maintaining effectiveness in controlling fluid movements during spacecraft maneuvers.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The net may be constructed from composite materials combining lightweight polymers or thin metallic alloys that provide sufficient mechanical strength to dampen sloshing while minimizing weight. These composite materials offer high strength-to-weight ratios, enabling the damping device to be lightweight yet structurally adequate for the application.

Inventive Principle:
Principle #40Composite materials

3Productivity

If expensive systems are deployed to prevent propellant vaporization, then performance loss is minimized, but the cost and weight of the spacecraft increase

Engineering Contradiction:
Improvespacecraft performanceVSAvoidspacecraft weight
Core Design Contradiction:
ProductivityVSWeight of stationary object

Solution Approach 1:

The damping net is designed as a simple, inexpensive structure made from readily available materials such as polymer wires or thin metallic strands. This cost-effective solution replaces expensive conventional damping systems, reducing both spacecraft weight and manufacturing cost while providing adequate protection against propellant vaporization losses during flight maneuvers.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention extracts only the essential damping function from complex conventional systems, implementing a simplified net structure that performs the core function of reducing sloshing and minimizing vaporization. By removing unnecessary complexity and weight from the damping system, the spacecraft achieves better performance without the burden of heavy, expensive equipment.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The device effectively reduces sloshing movements and associated vaporization losses, maintaining propellant quantity and enhancing spacecraft performance by using a flexible, lightweight design that adapts to various flight phases and fluid conditions.

Implementation Method 1

a net arranged on the plurality of rods and around the ring, the net comprising a mesh adapted to the viscosity of the fluid (to be damped) so as to dampen movements of said fluid

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP3867155B1Device for damping fluid in a reservoir, in particular of a spacecraft
Publication Date: 2023.05.31 ARIANEGRP SAS
  • EP3867155B1 patent drawingFigure 1~2
  • EP3867155B1 patent drawingFigure 3~4
  • EP3867155B1 patent drawingFigure 5~6

AI summary

The device (1) for damping a fluid intended for a reservoir (6) in particular of a spacecraft comprises a framework (3) provided with at least one ring (8) and with a plurality of rods (7), each of said rods (7) being fastened by a first end around said ring (8), said device (1) comprising a net (2) arranged on the plurality of rods (7) and around the ring (8), the net (2) comprising a mesh adapted to the viscosity of the fluid to be damped so as to damp movements of said fluid.