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Pulse Jar

Short answer: A pulse jet engine burns a fuel-air mixture in rapid, repeated pulses. Jar versions improvise the idea: a small opening lets air in, a flammable vapor such as alcohol is added, and ignition makes the burning gas build pressure and rush out of the opening, often pulsing.

The Reel itself calls this a highly dangerous experiment. The footage, credited to eurekahnb, shows a burning jar demonstration.

VideoWrite-up1 sources
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What should you know about Pulse Jar?

Quick facts. Each one stands alone and has a stable ID you can cite.

  1. Pulse jet.

    DD-586-F01 · Write-up · Exhibit A (Engine)

  2. Rapid pulses.

    DD-586-F02 · Write-up · Exhibit B (Cycle)

Video transcript: Pulse Jar: A Jar With a Small Hole Can Mimic a Pulse Jet Engine

Did you know, creating pulse jets in jars is a highly dangerous and improvised experiment that attempts to replicate the basic principles of a pulse jet engine in a confined space. A pulse jet operates by combusting a fuel air mixture in rapid pulses. In a jar setup, a small hole is typically made for air flow, and a flammable vapor like alcohol or gas is introduced inside. When ignited, the rapid combustion causes pressure to build up and expel hot gases out of the jar. NOW YOU KNOW!

Burned-in captions, read frame by frame (see transcript.md) · 24.7s Reel ·

Video coming soonPulse Jar · Instagram Reel
Pulse Jar: A Jar With a Small Hole Can Mimic a Pulse Jet Engine Instagram Reel · · 24.7s

The write-up

A jar with a small hole can mimic a pulse jet engine. Fuel vapor burns in rapid pulses.

  1. Exhibit A

    Engine

    Pulse jet.

  2. Exhibit B

    Cycle

    Rapid pulses.

  3. Exhibit C

    Jar setup

    Small opening.

  4. Exhibit D

    Fuel

    Alcohol vapor, per the Reel.

  5. Exhibit E

    Risk

    Highly dangerous, per the Reel.

Questions people ask about Pulse Jar

Mimics?

Pulses.

Source: Write-up · Exhibit A (Engine) · Wikipedia: Pulsejet

Combustion?

Cycle.

Source: Write-up · Exhibit B (Cycle) · Wikipedia: Pulsejet

Fuel example?

Vapor.

Source: Write-up · Exhibit C (Jar setup) · Wikipedia: Pulsejet

Air enters via?

Opening.

Source: Write-up · Exhibit D (Fuel) · Wikipedia: Pulsejet

Reel's warning?

Risk.

Source: Write-up · Exhibit E (Risk) · Wikipedia: Pulsejet

Test Your Knowledge

All quizzes →

5 questions, all from this case file. Answers are revealed instantly.

  1. Mimics?

    1. Pulse jet
    2. Turbofan
    3. Piston engine
    4. Rocket only
    Show the answer

    Answer: A. Pulse jet Pulses. Source: Write-up · Exhibit A (Engine) · Wikipedia: Pulsejet

  2. Combustion?

    1. In pulses
    2. Continuous
    3. None
    4. Electric
    Show the answer

    Answer: A. In pulses Cycle. Source: Write-up · Exhibit B (Cycle) · Wikipedia: Pulsejet

  3. Fuel example?

    1. Alcohol vapor
    2. Water
    3. Sand
    4. Salt
    Show the answer

    Answer: A. Alcohol vapor Vapor. Source: Write-up · Exhibit C (Jar setup) · Wikipedia: Pulsejet

  4. Air enters via?

    1. Small hole
    2. Lid fully closed
    3. Fan
    4. Pump
    Show the answer

    Answer: A. Small hole Opening. Source: Write-up · Exhibit D (Fuel) · Wikipedia: Pulsejet

  5. Reel's warning?

    1. Highly dangerous
    2. Totally safe
    3. For kids
    4. Silent
    Show the answer

    Answer: A. Highly dangerous Risk. Source: Write-up · Exhibit E (Risk) · Wikipedia: Pulsejet

Cite this case file

Easterling, Marcus. "Pulse Jar." The Detail Department (DetailEnjoyer), case file DD-586, last updated Jun 1, 2025. https://detailenjoyer.com/case/pulse-jar/

Permalink: https://detailenjoyer.com/case/pulse-jar/ · Last updated

Markdown version

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