Baffled-Tube Ram Accelerator for Projectile Velocity

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Solution Overview

Problem

Conventional powder guns face limitations in accelerating projectiles to high speeds due to increased friction and energy requirements as the projectile gains velocity, while ram accelerators struggle with maintaining propulsion efficiency over long distances.

Innovation Solution

A baffled ram accelerator system with a plurality of baffles arranged along the inner surface of the tube, creating sequential propellant chambers that isolate the combustion process behind the projectile, allowing for the use of more energetic propellants and reducing friction by preventing combustion-generated pressure waves from being driven upstream, thereby increasing thrust without increasing propellant pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If conventional powder guns are used to accelerate projectiles, then high initial thrust is achieved through propellant combustion, but the projectile slows down at high velocities due to increased friction and energy requirements

Engineering Contradiction:
Improveprojectile velocityVSAvoidenergy loss to friction
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The tube is divided into multiple chambers by baffles, creating a segmented structure. Each chamber allows for controlled propellant combustion and pressure wave management, enabling the projectile to maintain thrust over longer distances without excessive energy loss to friction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Baffles act as intermediary elements that manage the interaction between combustion-generated pressure waves and the projectile. The baffles reflect and direct pressure waves to maintain thrust while preventing harmful upstream propagation, serving as a mediator between the propellant combustion process and the projectile motion

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If ram accelerators are used to achieve high speeds, then the projectile can ride its own combustion wave, but propulsion efficiency decreases over long distances due to combustion pulse management issues

Engineering Contradiction:
Improveprojectile velocityVSAvoidpropulsion efficiency over distance
Core Design Contradiction:
SpeedVSDuration of action of moving object

Solution Approach 1:

The combustion process is segmented into discrete chambers by baffles, allowing each chamber to contribute to the combustion pulse. This segmentation enables sustained propulsion over longer distances by managing the combustion process in controlled stages, maintaining efficiency throughout the projectile's travel

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The baffled chamber design ensures continuous useful action by maintaining controlled combustion and pressure wave propagation throughout the tube. Each chamber contributes to the ongoing combustion pulse, ensuring continuous thrust generation rather than intermittent propulsion, thereby extending effective propulsion distance

Inventive Principle:
Principle #20Continuity of useful action

3Speed

If more energetic propellants are used in ram accelerators, then higher speeds can be achieved, but combustion-generated pressure waves are driven upstream causing instability

Engineering Contradiction:
Improveprojectile velocityVSAvoidcombustion process stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

Baffles segment the combustion chambers, confining pressure waves within each chamber and preventing upstream propagation. This segmentation allows more energetic propellants to be used safely, as the baffles contain the combustion process and maintain stability even with higher energy density propellants

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The baffles convert potentially harmful upstream-propagating pressure waves into beneficial localized combustion control. By reflecting and directing pressure waves, the baffles transform what would be destabilizing factors into controlled combustion drivers, enabling stable operation with more energetic propellants

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

4Duration of action of moving object

If propellant pressure is increased to maintain thrust over long distances, then propulsion efficiency improves, but the system complexity and safety requirements increase

Engineering Contradiction:
Improvepropulsion durationVSAvoidsystem complexity
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The tube is segmented into multiple chambers by baffles, allowing thrust to be maintained through controlled combustion in each chamber rather than requiring uniformly high propellant pressure throughout. This segmentation extends propulsion duration while maintaining relatively simple system architecture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Combustion occurs in periodic stages as the projectile passes through each baffled chamber. This periodic combustion action maintains thrust over extended distances without requiring continuous high propellant pressure, reducing system complexity and safety requirements compared to constant high-pressure systems

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

Enables the acceleration of projectiles to higher speeds by maintaining efficient propulsion over longer distances, as the baffles act as one-way valves, allowing the projectile to ride its own combustion wave and reducing friction, thus overcoming the limitations of conventional powder guns.

Implementation Method 1

a unique propulsive cycle can be initiated in which the projectile compresses and ignites the propellant as it travels through the tube. This results in a combustion pulse being accelerated down the tube

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 2

the baffles act as one-way valves, allowing the projectile to ride its own combustion wave and reducing friction

Methodology Applied
Scientific EffectPressure wave propagation: Shock Wave

Data Source

PatentEP3204714B1Baffled-tube ram accelerator
Publication Date: 2022.12.14 UNIV OF WASHINGTON
  • EP3204714B1 patent drawingFigure 1A~1C
  • EP3204714B1 patent drawingFigure 2A~2C
  • EP3204714B1 patent drawingFigure 2D~2E

AI summary

A baffled ram accelerator system includes a ram accelerator tube with an inner surface and an outer surface and a plurality of baffles disposed on the inner surface. The plurality of baffles forms a sequential series of propellant chambers along the longitudinal axis of the ram accelerator tube. An accelerator gun is also disposed on an input end of the ram accelerator tube, and the accelerator gun is positioned to fire a projectile into the ram accelerator tube.