Nested Pulse Detonation Actuator for High-Frequency Propulsion

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Solution Overview

Problem

Conventional pulse detonation/deflagration actuators and engines produce a pulsed output with limited operating frequency and magnitude, requiring additional space and complexity to increase efficiency, stability, and reliability.

Innovation Solution

A single containment pulse detonation/deflagration actuator/engine with multiple smaller internal combustion tubes positioned longitudinally or radially within the main tube, allowing initial combustion to occur inside each smaller tube and release into the larger tube, increasing operating frequency and magnitude of deflagration to detonation waves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional single-tube pulse detonation actuators are used, then the device structure is simple, but the operating frequency and magnitude of pulsed output are limited

Engineering Contradiction:
Improveoperating frequencyVSAvoiddevice structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies nesting by placing multiple internal combustion tubes inside a single outer containment tube. Each internal tube contains its own combustion chamber and can operate independently, while all are contained within the shared outer structure. This nested configuration allows multiple detonation events to occur simultaneously or sequentially within one device, increasing operating frequency without requiring multiple separate actuators.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent segments the combustion process by dividing it into multiple independent internal tubes, each capable of independent operation. This segmentation allows different portions of the device to operate at different phases or frequencies, which can be synchronized to produce higher aggregate operating frequencies while maintaining a single integrated device structure.

Inventive Principle:
Principle #1Segmentation

2Productivity

If multiple external tubes are used to increase operating frequency, then the aggregate operating frequency increases, but the space required and device complexity increase

Engineering Contradiction:
Improveaggregate operating frequencyVSAvoidspace required
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

By nesting multiple combustion tubes within a single outer tube, the patent achieves the functionality of multiple separate actuators while occupying the space of only one external device. The internal tubes share the common outer containment structure, fuel delivery system, and exhaust pathway, thereby increasing aggregate operating frequency without proportionally increasing the external footprint or required installation space.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Productivity

If multiple external tubes with high-speed valves are used, then the operating frequency increases, but the device complexity and maintenance cost increase

Engineering Contradiction:
Improveoperating frequencyVSAvoidvalve system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges the control functions into a centralized system located outside the containment tube, using a single valve assembly to distribute fuel to multiple internal tubes. This consolidation reduces the number of high-speed valves required compared to having separate valve systems for each tube, thereby reducing mechanical complexity and maintenance requirements while still enabling high-frequency operation across all internal tubes.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If conventional pulse detonation engines are used, then mechanical simplicity is maintained, but propulsion efficiency is limited

Engineering Contradiction:
Improvepropulsion efficiencyVSAvoiddevice structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent segments the propulsion system into multiple independent combustion tubes within a single engine structure. Each tube can be optimized for specific combustion parameters, allowing for improved thermodynamic efficiency and propulsion performance. The segmented design enables better control over exhaust timing and pressure waves, enhancing overall engine efficiency without fundamentally changing the pulse detonation mechanism.

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

This configuration enhances the operating frequency and magnitude of pulsed output, reducing space requirements and complexity while maintaining mechanical simplicity and thermodynamic efficiency, enabling higher propulsion efficiency and fluid flow control.

Implementation Method 1

a gaseous fuel is detonated within a chamber, causing a pulse detonation wave, which propagates at supersonic speeds. The detonation wave compresses the fluid within the chamber, increasing its pressure, density and temperature.

Methodology Applied
Scientific EffectDetonation: Detonation

Implementation Method 2

The detonation wave compresses the fluid within the chamber, increasing its pressure, density and temperature.

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

Conventional jet engines and the majority of rocket engines operate via subsonic combustion of fuel, known as deflagration.

Methodology Applied
Scientific EffectCombustion: Combustion

Implementation Method 4

Conventional jet engines and the majority of rocket engines operate via subsonic combustion of fuel, known as deflagration.

Methodology Applied
Scientific EffectDeflagration: Deflagration

Implementation Method 5

As the detonation wave passes out the open rearward end, thrust is created.

Methodology Applied
Scientific EffectThrust: Reaction (physics)

Data Source

PatentEP2157306B1Pulse detonation/deflagration apparatus and method for enhancing the production of detonation to deflagration waves
Publication Date: 2018.07.18 LOCKHEED MARTIN CORP
  • EP2157306B1 patent drawingFigure 1~3
  • EP2157306B1 patent drawingFigure 4~6
  • EP2157306B1 patent drawingFigure 7~9

AI summary

Pulse detonation/deflagration apparatus (30, 30') for providing enhanced pressure wave operating frequency and/or magnitude, and methods of increasing the frequency or the magnitude of deflagration to detonation waves (37), are provided. A pulse detonation/deflagration apparatus (30, 30') can include a main/outer pulse detonation/deflgration actuator/engine (31) with multiple smaller internal combustion chambers or tubes (33) positioned inside the cavity of the main/outer actuator/engine (31) with each performing the function of individual pulse detonation/deflagration actuator/engines (31), The output pressure waves (37) created by the internal combustion chambers or tubes (33) can be utilized for propulsion or for controlling large scale flows, where needed.