Variable Diaphragm Fluidic Retarder for Submarine Launch

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Solution Overview

Problem

Existing pressurized fluid supply systems for underwater vehicle launch tubes often apply excessive force during weapon ejection, leading to cavitation and reduced speed due to poorly adapted thrust laws.

Innovation Solution

The system incorporates variable diaphragm means with a needle valve and helical spring, allowing for adjustable calibration to optimize the force applied to the weapon, featuring a diaphragm body with varying fluid passage sections and adjustable elastic biasing, ensuring a more controlled and adapted thrust.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional fluidic retarder with fixed diaphragm means is used to brake the valve opening movement, then the valve opening is controlled, but the thrust law is poorly adapted causing excessive force and cavitation at the weapon base

Engineering Contradiction:
Improvevalve opening controlVSAvoidthrust law adaptation
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent applies the dynamics principle by replacing fixed diaphragm means with variable diaphragm means that automatically adapt their geometry based on the valve opening position. The diaphragm structure changes its effective area dynamically during the valve opening process, allowing the retarder to provide different braking forces at different stages of valve opening. This dynamic adaptation enables the system to optimize the thrust law for different weapon types without manual intervention, resolving the contradiction between controlled valve opening and adaptable thrust characteristics.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the physical geometry parameters of the diaphragm structure. The variable diaphragm means change its effective area, curvature, and shape parameters as the valve opens, which directly alters the fluid flow characteristics and braking force. This parameter variation allows the system to adapt the thrust law to match different weapon requirements, eliminating cavitation while maintaining controlled valve opening.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If fixed diaphragm means are used in the fluidic retarder, then the structure is simple, but the thrust characteristics cannot be adapted to different weapon types

Engineering Contradiction:
Improveretarder structureVSAvoidweapon type adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent transforms the static diaphragm structure into a dynamic one that automatically adapts to different operating conditions. The variable diaphragm means respond to pressure differentials and valve position to change their geometry, providing inherent adaptability to different weapon types without requiring complex external control systems or multiple fixed diaphragm configurations. This maintains structural simplicity while achieving versatility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent achieves universality by designing a single variable diaphragm structure that can handle multiple weapon types with different mass, length, and geometry requirements. The self-adjusting nature of the variable diaphragm allows the same retarder mechanism to optimize thrust characteristics for various weapons, eliminating the need for weapon-specific configurations or complex adjustment mechanisms.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Force

If the force applied to the weapon is increased to ensure proper ejection, then the launch capability is improved, but cavitation occurs at the weapon base reducing ejection speed

Engineering Contradiction:
Improveejection forceVSAvoidejection speed
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The patent resolves this contradiction by dynamically changing the pressure distribution parameters across the weapon base during ejection. The variable diaphragm means adjust the effective area and flow characteristics to optimize the thrust law, ensuring sufficient ejection force while preventing excessive pressure concentrations that cause cavitation. This parameter optimization allows high ejection force without sacrificing ejection speed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs periodic action through the dynamic response of the variable diaphragm structure during the ejection process. The diaphragm continuously adjusts its geometry in response to changing pressure differentials, creating an optimized pressure distribution pattern that maintains ejection force while preventing cavitation. This dynamic periodic adjustment ensures optimal performance throughout the ejection cycle.

Inventive Principle:
Principle #19Periodic 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 solution reduces the maximum force applied to the weapon, enhances acceleration dynamics, and minimizes cavitation, resulting in improved ejection speed and performance.

Implementation Method 1

a needle (21) mounted so as to be able to move in this diaphragm body under the action of the fluid and therefore depending on the position of the valve, against the stress of elastic means

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the elastic means comprise a helical spring, one end of which is associated with a bearing surface of the needle valve and the other end of which is associated with the means for adjusting the calibration of this spring

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 3

A needle (21) mounted so as to be able to move in this diaphragm body under the action of the fluid and therefore depending on the position of the valve

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 4

a fluidic retarder with two fluid chambers connected through diaphragm means for laminating this fluid

Methodology Applied
Scientific EffectLaminar flow: Laminar Flow

Data Source

PatentEP2343491B1System for feeding with pressurised fluid an ejection piston of a launching tube of a weapon on a submarine
Publication Date: 2013.12.25 DCNS SA
  • EP2343491B1 patent drawingFigure 1
  • EP2343491B1 patent drawingFigure 2
  • EP2343491B1 patent drawingFigure 3

AI summary

The system has a launching valve interposed between a pressurized fluid source and a rammer. The valve includes a valve body (5) in which a removable valve (6) is mounted during launching of a weapon by a control unit between a closing position and an opening position of the valve to supply pressurized fluid to the rammer. The removable valve is associated with a braking unit (8) including a fluidic speed reducer with two fluid chambers (9, 10) connected together by a diaphragm unit for controlling the fluid. The diaphragm unit is variable according to the position of the removable valve.