Electronic Thermally-Initiated Venting System for Rocket Motor Safety

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Rocket motors face safety challenges due to thermal cookoff conditions, where energetic materials can decompose and lead to explosions, and existing technologies lack effective means to manage temperature gradients and slow or rapid heat exposure.

Innovation Solution

An electronic thermally-initiated venting system (ETIVS) is implemented, using a thermally-insulated circuit with a thermal battery, integrated circuits, and a linear-shaped charge, which senses temperature and generates a current pulse to initiate the venting system, preventing pressure buildup and potential explosions through sequenced arming energy locks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional thermal venting systems are used, then the structure is simple, but the system cannot effectively manage temperature gradients and cookoff conditions

Engineering Contradiction:

Improvesafety under cookoff conditionsVSAvoidventing system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical thermal sensing mechanisms with electronic temperature sensing circuits that can accurately detect temperature gradients and cookoff conditions. The electronic system processes thermal information and triggers venting only when predetermined safety criteria are met, providing intelligent decision-making capability that mechanical systems lack.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an electronic intermediary system between the thermal environment and the venting mechanism. This intermediary processes temperature data, evaluates cookoff conditions, and determines when venting is necessary, adding a layer of intelligent control that resolves the contradiction between safety and complexity.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If electronic temperature sensing is implemented, then temperature detection accuracy improves, but energy consumption increases

Engineering Contradiction:

Improvetemperature sensing accuracyVSAvoidcircuit power consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent employs periodic sampling of temperature data rather than continuous monitoring. The electronic circuit measures temperature at intervals and evaluates cookoff conditions only when necessary, significantly reducing power consumption while maintaining accurate temperature detection capability when needed.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes the operational state of the electronic circuit from continuous active monitoring to intermittent activation. The circuit remains in a low-power state and activates only when temperature thresholds are approached or cookoff conditions are detected, optimizing the balance between measurement precision and energy consumption.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If multiple sequenced arming energy locks are added, then safety against premature detonation improves, but device complexity increases

Engineering Contradiction:

Improveprotection against premature detonationVSAvoidventing system structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements multiple sequenced arming energy locks that must be satisfied in a specific sequence before venting can occur. This preliminary action requirement ensures that venting is triggered only under genuine cookoff conditions and not due to premature or false signals, enhancing safety through structured procedural controls.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent divides the arming process into multiple sequential stages or locks, each verifying specific safety conditions. This segmentation of the triggering mechanism into discrete, verifiable steps provides robust protection against premature detonation while maintaining a systematic approach that manages complexity through modular design.

Inventive Principle:

Principle #1Segmentation

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 ETIVS effectively manages temperature gradients and cookoff conditions, reducing the risk of explosions by venting the rocket motor case before pressure buildup, ensuring safety under both slow and fast cookoff scenarios.

Implementation Method 1

a thermal battery configured to generate power in response to a temperature exceeding a threshold temperature

Methodology Applied

Scientific EffectThermal energy conversion: Seebeck Effect

Implementation Method 2

a linear-shaped charge configured to create a jet of material in response to the current pulse from the thermal battery

Methodology Applied

Scientific EffectShaped charge: Shaped Charge

Data Source

PatentUS10670381B1Electronic thermally-initiated venting system (ETIVS) for rocket motors

Publication Date: 2020.06.02 THE UNITED STATES OF AMERICA AS REPRESENTED BY THE SECRETARY OF THE NAVY

AI summary

An electronic thermally-initiated venting system (ETIVS) for rocket motors includes at least one linear-shaped charge attached to a rocket motor housing. At least one exploding foil initiator (EFI) is attached to the linear-shaped charge. At least one electronic thermally-initiated venting system circuit is electrically-connected to the EFI. The EFI is configured to auto-fire when the electronic thermally-initiated venting system circuit relays a current pulse through the EFI. The linear-shaped charge is configured to initiate when the current pulse is relayed through the EFI.