Textile Fabric Bag Missile Acceleration with Controlled Gas Permeability

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Solution Overview

Problem

Existing missile launch systems face challenges in efficiently accelerating missiles while ensuring safety and ease of operation, particularly in preventing explosive gas release during decompression.

Innovation Solution

A launch device with a gas generator and a textile fabric bag that inflates to accelerate the missile, featuring controlled gas permeability and a tapered cross-section for efficient acceleration and rapid depressurization, along with a detachable control module and a plate for improved power transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a gas generator is used to inflate the bag for missile acceleration, then the missile can be accelerated to desired speed, but there is a risk of explosive gas release during decompression

Engineering Contradiction:
Improvemissile acceleration speedVSAvoidexplosive gas release risk
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The bag is made from a textile fabric with controlled gas permeability (10-10000 l/dm²/min), allowing propellant gas to permeate through the bag walls during decompression. This controlled porosity prevents explosive gas release by allowing gradual gas escape while maintaining structural integrity during missile acceleration.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The harmful propellant gas that needs to be disposed of after acceleration is converted into a beneficial cooling and pressure-equalizing agent. The gas permeability allows the hot propellant gas to cool the bag structure and equalize pressure gradually, transforming the harmful hot gas into a useful cooling medium that prevents thermal damage and explosive decompression.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Power

If the bag is made from impermeable material to maintain pressure for acceleration, then acceleration efficiency is improved, but the bag cannot rapidly depressurize after ejection

Engineering Contradiction:
Improveacceleration powerVSAvoiddepressurization time
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

The textile fabric with controlled gas permeability creates a balance between pressure retention and gas escape. The permeability range (10-10000 l/dm²/min) is optimized to maintain sufficient pressure for powerful acceleration while allowing rapid depressurization after missile ejection, eliminating the need for separate venting mechanisms.

Inventive Principle:
Principle #31Porous materials

3Ease of manufacture

If the bag cross-section is uniform to simplify manufacturing, then manufacturing complexity is reduced, but acceleration efficiency is decreased

Engineering Contradiction:
Improvebag manufacturing simplicityVSAvoidacceleration efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The bag features a tapered cross-section design where the width varies along the longitudinal axis, with the widest section at the closed end and narrowing toward the open end. This local variation in geometry optimizes pressure distribution and force application to the missile, improving acceleration efficiency while remaining compatible with standard textile manufacturing processes.

Inventive Principle:
Principle #3Local quality

4Reliability

If the bag is made from highly durable material to withstand high pressure, then reliability is improved, but the bag weight increases

Engineering Contradiction:
Improvebag pressure resistanceVSAvoidbag weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The textile fabric with controlled porosity provides an optimal balance between weight and strength. The porous structure allows the use of lighter materials that would otherwise be insufficient for containing high pressure, while the controlled permeability and structural design ensure the bag can withstand the required pressures for missile acceleration without excessive weight.

Inventive Principle:
Principle #31Porous materials

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 system effectively accelerates missiles while minimizing the risk of explosive gas release and facilitating safe operation and maintenance by quickly collapsing the bag post-ejection, enhancing safety and operational simplicity.

Implementation Method 1

a gas generator (20), which can be activated in order to generate a gas mass flow

Methodology Applied
Scientific EffectGas generation:

Implementation Method 2

The bag (21) has a gas permeability in a range between 10 l dm‑2 min‑1 and 10000 l dm‑2 min‑1, in particular in a range between 100 l dm‑2 min‑1 and 1000 l dm‑2 min‑1

Methodology Applied
Scientific EffectGas permeability: Permeation

Data Source

PatentEP3736523B1System and device for starting a missile
Publication Date: 2023.07.19 MBDA DEUTSCHIAND GMBH
  • EP3736523B1 patent drawingFigure 1~5
  • EP3736523B1 patent drawingFigure 6~7

AI summary

A launching device for launching a missile comprises a longitudinally extending launch tube for receiving the missile, which has an outlet opening at one end, and an acceleration device located at the second end of the launch tube. The acceleration device includes a gas generator that can be activated to generate a gas mass flow, and a sack made of a textile fabric. The sack is coupled at one end opening to a diffuser of the gas generator and can be inflated by the gas mass flow generated by the gas generator to accelerate the missile along its longitudinal axis. The sack has a gas permeability in the range of 10 dm⁻² min⁻¹ to 30 dm⁻² min⁻¹.Alternatively or additionally, in an inflated state, a cross-section of the bag tapers from the end opening along the longitudinal direction to a minimal cross-section and then increases again to an end opposite the end opening.