simple pulse jet fuel

[FishBoy]

I am trying to make a simple pulse jet like this, mainly just for fun and I might turn it in to a simple "bath tub" boat. Anyway, I don't have methanol (the preferred fuel) but I do have other things. Please let me know if any of them will work-

1-rubbing alchohol

2-Denatured alchohol

3-turpentine

4-acetone

[Insomniac]

It's me!

Ok, the fuel I was using is called methylated spirits here in Aus, but I'm pretty sure it is sold as Denatured Alcohol in the US. Basically it is ethanol with a bit of methanol added. It works fine.

If you try a jet the same as what I made, there are a few problems you will run into:

1. Hole size. Too small and it will go 'BRRRRRRRRRP' really loudly then stop very quickly. Too large and it will go 'WHOOOOOSH' without starting any pulsed combustion. Keep in mind that even a perfectly sized hole can do both of these things, so test the hole with quite a few starts to see if it is consistently failing the same way, and THEN adjust accordingly. It only takes utterly minute changes in the size of the hole for it to go from not-working to working. Just take it slow and keep attempting.

2. Air/fuel mix. Depending on the temperature of the jet, you may find it tricky to get enough fuel to vapourize for it to light. Usually what I get is one start where it simply goes 'WHOOOSH' then nothing... This heats it up enough to light more reliably. Make sure you get PLENTY of fresh air in, then block the hole and give it a shake. If there is enough loose fuel dripping down the inside walls, it will somtimes shoot out a jet of flame with quite a loud noise, so don't put your face over it.

3. Even once you get it running, it will only work for about ten seconds or so, max. This is because it gets so darned hot that the fuel just boils off too fast and overwhelms it with an overly rich mix. In my version, as you can see in the vid, I used a couple of hard-drive magnets on either side of the container to let me submerse the jet partially in water without it floating to the top. This works very well and lets you get quite long runs out of it.

4. I have had little success in making this engine run at an angle/horizontally. If you want it to propel somthing the best idea would be some sort of deflecter for the exhaust. It wouldn't be terribly efficiant, but should at least make it easier to light.

5. These engines are picky about when they will run. I have two, one with a slightly larger hole than the other. On any given day one or the other might run better than the other. I guess this is because of how dense the air is at that time.

6. Even once you get a perfectly tuned engine, expect to have 10-20 false starts before you get a decent run out of it. Perhaps there is somthing wrong with the shape of the can I used (although it is the only can I managed to get to work) or maybe it is just in the nature of this type of jet. They don't like to start, and somtimes when they do they will just decide to stop. They need everything to be perfect before they will start.

[Gippeto]

Methanol = Methyl Hydrate = Air brake anti-freeze = gas line anti-freeze

http://en.wikipedia.org/wiki/Methyl_hydrate

Try NAPA.

[inonickname]

Probably methylated spirits, turps (turpentine) or acetone.

Off topic:


I'm looking at building a similar adaption of that. I have the pipes, but does anyone have suggestions as to how to build the reducing parts? I have copper or stainless pipe that will work, and welding isn't much of an option.

Edit: typo.

[FishBoy]

*I'm done with this thread, so I approve his hijacking of it*

[Insomniac]

*I'm done with this thread, so I approve his hijacking of it*

Does that mean you got it working, or that you just couldn't be bothered?

[DR]

Rubbing alcohol is difficult to find, in a concentration that is over 70%, although (on rare occasions) you can find it at 91%. The current bottle that I have in my garage (just for cleaning parts) is only a miserable 50%.

Denatured Alcohol is extremely toxic and can be absorbed through the skin, as well as inhaled, which will damage your lungs if used in anything other than an extremely well-ventilated area.

INHALATION: Irritating to upper respiratory tract. Remove patient to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Seek medical attention immediately

INGESTION: Poisonous, may damage central nervous system and internal organs and cause blindness. DO NOT induce vomiting. Have conscious person drink several glasses of water or milk. Never give anything by mouth to an unconscious person. Lower the head so that vomit will not re-enter the mouth and throat. Seek medical attention immediately.

EYE CONTACT: Irritating, can cause colour blindness. Check for and remove any contact lenses. Rinse eyes for at least 20 minutes with cold water. Seel medical attention immediately.

SKIN CONTACT: Only hazardous with prolonged contact. Wash immediately with plenty of water for at least 20 minutes. Thoroughly clean contaminated clothing and shoes before re-use. Seek medical attention.

OTHER HEALTH INFORMATION:
Potential Acute health effects: Very hazardous in case of eye contact (irritant), ingestion or inhalation. hazardous in case of skin contact (permeator). Slightly hazardous in case of skin contact (irritant). Severe over-exposure can result in death. Inflammation of the eye is characterized by redness, watering and itching.
Potential Chronic health effects:
Carcinogenic effects: Classified A4 by ACGIH (for ethyl alcohol) - (Not Classifiable for human or animal)
Mutagenic effects: Not available
Teratogenic effects: Not available
Developmental toxicity: Not available
This substance is toxic to the liver. Repeated or prolonged exposure can produce target organs damage. Repeated exposure to a highly toxic material may produce general deterioration of health by an accumulation in one or many organs.

FLAMMABLE LIMITS IN AIR; % BY VOL. LOWER: Ethyl alcohol: 4.3%; Methyl alcohol: 6%

FLAMMABLE LIMITS IN AIR; % BY VOL. UPPER: Ethyl alcohol: 19%; Methyl alcohol: 36.5%

Turpentine:

Potential Acute Health Effects:
Very hazardous in case of ingestion. Hazardous in case of skin contact (irritant), of eye contact (irritant), of
inhalation. Slightly hazardous in case of skin contact (permeator).
Potential Chronic Health Effects:
CARCINOGENIC EFFECTS: A4 (Not classifiable for human or animal.) by ACGIH.
MUTAGENIC EFFECTS: Not available.
TERATOGENIC EFFECTS: Not available.
DEVELOPMENTAL TOXICITY: Not available.
The substance may be toxic to kidneys, lungs, bladder, gastrointestinal tract, upper respiratory tract, skin, eyes,
Urinary System, central nervous system (CNS), ears, nose/sinuses.
Repeated or prolonged exposure to the substance can produce target organs damage.

Flammable Limits: LOWER: 0.8%


Acetone:

Danger! Extremely flammable liquid and vapor. Vapor may cause flash fire. Causes eye irritation. Breathing vapors may cause drowsiness and dizziness. Causes respiratory tract irritation. Aspiration hazard if swallowed. Can enter lungs and cause damage. Prolonged or repeated contact may dry the skin and cause irritation.
Target Organs: Central nervous system, respiratory system, eyes, skin.


Potential Health Effects
Eye: Produces irritation, characterized by a burning sensation, redness, tearing, inflammation, and possible corneal injury. Vapors cause eye irritation.
Skin: May be absorbed through the skin. Repeated or prolonged exposure may cause drying and cracking of the skin.
Ingestion: May cause irritation of the digestive tract. May cause central nervous system depression, characterized by excitement, followed by headache, dizziness, drowsiness, and nausea. Advanced stages may cause collapse, unconsciousness, coma and possible death due to respiratory failure. Aspiration of material into the lungs may cause chemical pneumonitis, which may be fatal.
Inhalation: Inhalation of high concentrations may cause central nervous system effects characterized by nausea, headache, dizziness, unconsciousness and coma. Causes respiratory tract irritation. May cause motor incoordination and speech abnormalities.
Chronic: Prolonged or repeated skin contact may cause dermatitis. Chronic inhalation may cause effects similar to those of acute inhalation. Matsushita et al. exposed human volunteers 6 hours/day for 6 days at 500 ppm acetone and found hematologic changes including significantly increased leukocyte and eosinophil counts and decreased neutrophil phagocytic activity.

Explosion Limits, Lower:2.5%
Upper: 12.8%


... Personally, I wouldn't screw around with ANY of the last three mentioned!

[starman]

Yes they can be dangerous...if you're stupid. Laundry bleach and bath tube cleaner can also be just as dangerous...if you're stupid. My Braun electric shaver has a cleaning system that includes a bath in denatured alcohol...the same shaver I put to my face a few minutes afterward. All of these products have valuable uses in household situations. If you need turpentine or acetone for a particular job, by all means use them carefully...with gusto...

Using them as pulse jet fuel isn't a good idea though... for the sheer expense of it if nothing else. Why not use gasoline, kerosene or propane...maybe RC engine fuel, something generally designed for applications like this?

[sniper hero]

wow
when I saw the video my first thought was : I'm going to make one
but after reading the thread I'm not so sure of it
and my compliments to insomaniac because you did a lot of effort to get it working and kept on trying. good work

[FishBoy]

...Why not use gasoline, kerosene or propane...maybe RC engine fuel, something generally designed for applications like this?

Thanks, I actually had some luck with the denatured alchohol, but I never thought of kerosene, which I also have. thanks.

[TurboSuper]

Didn't they wash people in turpentine when they got skunked...or is that just a myth?

...and a good electronics specialty store should sell isopropyl alcohol with a concentration in excess of 99%.

[DR]

Yes they can be dangerous...if you're stupid. Laundry bleach and bath tube cleaner can also be just as dangerous...if you're stupid. My Braun electric shaver has a cleaning system that includes a bath in denatured alcohol...the same shaver I put to my face a few minutes afterward. All of these products have valuable uses in household situations. If you need turpentine or acetone for a particular job, by all means use them carefully...with gusto...

This is what can happen, while using acetone for a pulse-jet engine fuel:

<a href="http://www.alexinwonderland.com/images/ ... g">Acetone burn victim</a>

<a href="http://www.spudfiles.com/forums/logout= ... >Denatured Alcohol burn victim / Home-made pulse jet dangers</a>

[Tidbit77]

my moneys on 30% nitro rc heli fuel, http://www3.towerhobbies.com/cgi-bin/wt ... LXGHB5&P=0
or if you want moar poewer!!! go with this 40% nitro http://www3.towerhobbies.com/cgi-bin/wt ... LXGHC4&P=0

[POLAND_SPUD]

http://www.alexinwonderland.com/ check the main page first then say you are sorry

[starman]

This is what can happen, while using acetone for a pulse-jet engine fuel:

Uum DR, the "acetone burn victim" is pretty gruesome but very fake. The website you pointed to is a make-up and prosthetics company... www.alexinwonderland.com located up in the Valley north of Hollywood....yeah, that Hollywood..

The denatured alcohol victim link pointed to the wrong/missing link page within Spudfiles somewhere.

What gives...?