10 Lb Thermojet Valveless Pulse Jet Engine
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- Опубликовано: 6 окт 2024
- www.PulseJetEng...
This is a 10 lb thermojet valveless pulsejet engine, all tig welded stainess steel. It is self starting, most pulsejets need to be provided with compressed or blown air in order to start the engine. This engine you can either light the propane with a torch or gril lighter, or a spark plug, and it will start right up.
The engine is a valveless pulsejet with no moving parts, and easily self starts on propane, just turn on the ignition and turn on the fuel....
A valveless pulsejet is a unique type of engine with no moving parts. Unlike ramjets, which must have air blown into them at high speed, either by a blower or by traveling very fast, pulsejets can run while completely still.
They can be throttled typically between 10% and 100% thrust in the blink of an eye, and dont require any spool up time like turbines or turbojets.
Because they have no moving parts, valveless pulse jets are much easier to own and operate than RC turbines. For the cost of a ducted fan setup, you could have your own real, high speed RC jet plane.
The truth is that by the time you add up turbojet planes engine weight, fuel and oil pump weight, the computerized control system, and any onboard starting systems, you not only have a small fortune invested in the plane, but its also quite heavy. Pulsejets can be made extremely light weight, and even valveless engines are capable of pumping their own liquid fuels by the venturi effect. All you then need is your standard reciever and servos and a small battery to power it, rather than a large battery to power a fuel pump.
Stainless is an extremely good insulator, you can hold your hand within 3" of the engine. Add to that the fact that propane expands and acts like a refrigerant, after a minute or two of running the propane tank can actually form ice on the tank. If you sit around and do nothing for the time it takes for the tank to heat up to the point where something bad can happen, you would have to be an idiot. Common sense is keeping something for putting out fires near by, no different from a BBQ grill.
nice lamp
Its about 1000 degrees away from melting, you can hold your hand 6" away from the chamber just fine, the propane tank 4' away is actually chilled considerably by the evaporating propane.
If anybody wants to try this engine, it is important to switch to liquid fuel when the engine reaches operating temperature. If you operate the engine on propane vapor, thrust will decrease rapidly. You can only get 60 percent power with propane vapor. this is because the volume of the combustion chamber is not the same for propane vapor and liquid fuel. Propane vapor will take more space. Therefore, with propane vapor, the volume of the combustion chamber will be small. This information is from the Thermojet patent (US patent 3,517,510. page 4)
Andrew Shingange switch to another fuel lin3
That shot looking down into the chamber was just awesome.
I would seriously consider moving the propane tank to the outside of the shed and run a longer hose. Could be a disaster being that close to the glowing part of engine.
Segurança NOTA 10 pra esse cara pqp...
This guy think Safety certainly ò.Ó
0:42 I expected a mini boom, and got that cute PFT sound :D
That is true. Once it gets hot, the cycle continues on it's own.
I think you are super awsome and smart. I built a u type valveless pulsejet but cant get it to light. So i am going to copy yours. Thank you smart gentlemen.
Thanks :) Nice to see you on here too :)
"MOVE THE BLOODY PROPANE TANKS!!~"
Haha, I was thinking the same thing.
Ikr. It’s terrifyingly close.
Pulse jets have been known to run on anything from sawdust, coal dust, to diesel and petrol.
Thanks for your help, and I'll stick with making mini-models for now XD
Core temps of the pulsejet are close to the temperature limits of the fuel burning in a higher oxygen environment. Propane will produce a core gas temp of over 2600 F very easily. Propane stoves, or even torches for that matter wont really melt steel, but if you stick a steel bar in the tail pipe of a pulsejet, it will melt very rapidly and shoot globs and sparks of molten metal out of the engine.
Another interesting thing is that mild steel engines will have lower core gas temps than stainless engines. The mild steel conducts and radiates heat away so much more rapidly than stainless. A mild steel engine can give you an infra red "sun burn" up to a foot or two away, where on a cool day you can put your hand right next to a stainless engine for a few seconds without discomfort. The energy that doesnt escape from a stainless engine is kept in the exhaust to do work and create thrust.
Wrap it in some Kaowool/Inswool, ceramic wool that can stand up to 2800-3000 degrees F. Great insulator and will probably enhance efficiency as more energy is directed out of the exhaust and not radiated off as heat. I use it in my propane forge, 2" thick, and the steel shell only gets up to a few hundred degrees despite the inside behind bright yellow orange.
The pressure changes rapidly, but you can measure the pressure with the right equipment, peak pressure is about 60 psi, the min pressure goes down to about 7 below atmospheric.
10 lbs thrust, with a special mix of methanol and gasoline and a model turbine fuel pump One of these has put out around 14 lbs thrust on a RC setup.
Pulse jet engines are pretty easy, you ignite the fuel, and a "pulse" is created. The resulting vacuum pulls more fuel into the combustion chamber, and it ignites again. This process repeats and creates a jet engine.
With how good of an insulator stainless steel is, and how much propane cools when it expands out of vapor form, putting the engine directly against the propane tank would possibly just barely make up for how much the tank is cooled.
A few minutes of running will cause the tank to form ice on it, 28lbs of steel + 20 lbs of propane all cooled below freezing would take a lot of heat input to not only keep up with the cooling but cause it to over pressurize.
That Thermojet is a cool engine. Now that I have a better job making better money I can save to buy me a TIG welder and start making these things like to make a scaled down V1 to mount to my bike and go buzzing down the road.
Great video! amazing how the combustion chambers lights up!
amazing work friend
I would think that the header tape would probably cause the stainless to melt as it would prevent a lot of heat from excaping. Ceramic lining a pulsejet on the other hand would keep the stainless from absorbing a lot of heat in the first place. Doing both could have some very interesting results.
can u send me a blueprint of ur engine plz. i m making a smaller version for a project
mild will do, but it will deteriorate after a while. i built a small one with .060 thick mild steel and only ran it 7 times before it burned up. im trying to come up with a design that uses standard plumming parts so more people can make them.
Butane does not burn very quickly but you should still be able to get an engine going on it. You need an ignition source in the combustion chamber for best effect, if it doesnt ignite in the right spot it wont build up to the explosion like combustion.
I would enjoy fabricating one of these. My house is heated by a pulse jet furnace. Very interesting.
That looks VERY safe.
Cool project, I'm thinking of building one myself....
Fine Engine Eric: Jim
Its not really an overheating problem, they are designed to run that hot, using stainless to handle the prolonged high temps. You can run them on RC planes, liquid fuel systems with pumps work the best.
@BeckTechnologies 1. Put it in a plane to demo it. (ie fly it)
2.Show how you propose to carry liquid Propane in the plane (and control flow rate)
3. Show the engine on a test rig doing 1lb up to 10lbs thrust.
4..Demonstrate thust to weight ratio.
Dimensions are rather important, cant just stick a bunch of tubes together and expect it to do anything other than burn fuel and make noise if it runs at all. With some engines altering the dimensions 1/8" can result in a 50% increase or decrease in thrust.
@Themayseffect Pulsejets will run on almost anything that burns, but if you deal with them on a daily basis, you'd probably go with propane too, since you dont come home every night stinking of kerosene. Methanol mixed with hydrocarbon fuels produce very good results. Hydrocarbons will burn significantly cleaner with methanol mixed in.
Nicely done.
I found this in Gmod. I tried to stop it and you killed me!
"And you killed me" how did he kill you? This isn't a game! Someone probably just made a jet in Gmod and uses it.
The design is mine, roughly based on the Thermojet design, except with huge changes to the intake lengths and configuration for better performance.
Thanks for pointing this out, unfortunately the internet is full of uninformed people who think things explode like in the movies they watch, and thats the extent of their knowledge of the subject.
That's pretty neat.
That's 10lb thrust. A lot of people use propane. It can be as cheap as the cost of scrap metal and some brake lines if you know how to weld. Now sure you could rig it on a bike, gokart or whatever, but I'd be iffy about ridding along with a red hot piece of steel. Plus you can't run them very long without running the risk of failure.
lol i was waiting for the gas containers RIGHT NEXT to the glowing hot end of the jet to explode or something
cooooooooooooooooooooool goes into my favorites list
awesome video. you should make a tutorial on how to make one
wow! future sound of airline!
wow that got hot very fast..
@EnglishTurbines
That particular video was running on a nearly empty, cold tank, so it was not at max throttle. At max throttle it is much more like the videos of the 4lb thrust engine, with distinctive shock wave pattern in the exhaust. The engine will put out approx 14 lbs on liquid fuel like methanol, you dont fly with propane. Propane is simply a clean easy no mess no fuss fuel for ground tests and demos. You dont go home smelling like kerosene at the end of the day.
So if you want to heat something up really fast, and make a lot of noise while you do so, this is the technology for you ;)
@EnglishTurbines
The evaporative cooling from methanol results in a much higher fuel charge density, combined with its rapid burn speed, result in much more thrust output.
Maybe this works better as an efficient heater :)
Anyway, great video!
HEY!!! ITS A LAMP lol but that thing is shining!!
Nope, the strength of the metal is more than enough to contain the pressure. The way pulsejets work, part of the cycle they are below atmospheric pressure, if the metal becomes hot enough to be damaged it will squish flat rather than explode out, the force to crush a tube is many many times less than the force to burst it.
interesting for an R/C setup but how much thrust does it produce and would the extreme heat be a problem?
Stainless steel has one of the highest insulating values of any high temp metal. It gets hot but the amount of heat that it radiates away is suprisingly low.
If it were a steady combustor turbulence could be bad, but the pulsating combustion is actually greatly enhanced by the right kind of turbulence. The more turbulence the faster the fuel and air mix, and the pulse of combustion will be faster and more powerful. The turbulence also allows the engine to self start.
Because when they ran out of fuel (acetylene) there was a flap that deployed to make them dive
I bet the birds shut up fairly quickly! :)
Interesting. How much weight can it move? say we put one on the back of a Kid's wagon. How fast would it go? What about a common Go Kart?
Also, is it smart to have your fuel tank infront of it?What it it breaks loose from it's mount and rams your Propane as it fly's off?
Unfortunately you cant just buy parts for pulsejets, we make all the parts from flat sheet metal and roll them and weld them up.
We also offer partially completed engine kits with all the materials you need, and most parts rough cut / formed
I purchased the FWE engine Beck makes. It's a 1 pound thrust engine. I also have a HK Red Head valved engine rated at 3 1/2 pound of thrust. There miles apart BUT the valveless engine just runs & runs & the HK always has issues. I went through 5 valves in 20 minutes of running. Anyway I have a 10 pound valveless engine from Beck coming in any day. WHEN ??? They answer no emails at all & the FWE had zero instructions. I will have a good gauge now to see if the 10 lb. engine is 10 lb or 3 1/2 . I will post it as soon as I test run it.
TrueBlogge777, the V-2 ballistic missiles were powered by liquid fueled rocket engines, not jet engines like the V-1 cruise missiles. Perhaps you were confused by the fuel pumps used in the V-2s.
yeah v 1's used a pulse jet while v2's used a c-stof and t-stof rocket
Your vice will no longer have its temper ;)
No, propane burns, it cant explode in the tank. The only way to make a propane tank rupture ( most have safety release valves to avoid this) is to stick it in a fire and wait. It is going to take a lot of energy to heat up the 28 lb tank, and the 20 lbs of fuel inside it. If you sit around for the 2-5 minutes that a propane tank is sitting in flames then In my opinion you kind of deserve it. Though with the tank open, and gas flowing out, any fire would melt the rubber fuel line, and blow out.
Maby some injected substances like water or water vapor could boost the thrust ability.
Hy,
I plan to build such an engine myself-valveless...and I had a few ideas of how to improve it!What's do you think about:
1. A ceramic (or asbestos?) coating inside the combustion chamber. It would protect the outer metal shell and it would increase the combustion temperature thus increasing the fuel efficiency and power?
2. A turbo, powered by some exhaust that would in turn send compressed air into the intake?
3. Linking 2 eng. in a series? exhaust to intake.
Thanx, Alex C
@BeckTechnologies Why don't you make a video showing the performance difference of the same engine with different fuels?
i was waiting for the spark, propane tank & boooooommmmm, seriously though how would you fit that in a model with out it catching on fire
jeez it got hot did u try to measure the temperature with temp gun ??? bet l=its like 1000F
I went to sub your channel and discovered i already had lol
a chamber (combustion chamber) gets filled with gas, (the end bit thats fat on this video) then a spark plug ignites it all and the gas creates a big bust of air (also can be provided by air compresser) that pushes a continuous flame out the flame tube. the spark plug doesnt have to be sparking at a constant cus the flame from the first fire keeps it going. and the gas has to be flowing at a continues flow. any more questions about em?
i dont know much about the abilities of mixing gases but there seems to be an argument over using methanol or kerosine. is it possible or has anyone tried mixing the 2 to creating a different type of burning process? more of a curious question.
@BeckTechnologies 5. Whilst the ease of starting is excelent, I have my doubts about the trhust claims, Does not look like enough air mass flow to do 10lbs thrust to me.
6. As you may have guessed, Im an engineer, and have made my own Turbojet for about 500USD...13lbs thrust @ 160K...see my Link.
Now to figure out a way to stop the combustion chamber from melting
is it able to install on an rc jet plane? its usually the valved ones that go on them.
so if you can put it on a rc plane, do you use a fuel other than propane?
times even the air trying to put into rotation? should bring more power
How long can it run before it melts down?
I'd love to build one to fly here at my club. it would drive the old guys crazy. hehe
I was wondering that what's the radius of the chamber's back-panel?
Is it just trial and error in building these engines or you have to know and apply different formulas in sizing and dimensions?
Also can this particular model be run on liquid fuel?
Thanks
@BeckTechnologies yea that i know. so what about nitromethane and alcohol. ive never seen those fuels used in turbines or pulsejets/dynajets
@Themayseffect methanol - nitromethane fuel is the standard, and only allowed fuel in competition pulsejet speed flying events.
So how many Lbs the contraption weights with a spark plug configuration?
How big of a battery for the ignition?
How long can it run continuous at 1%,10%,50%,100%?
What is the time from spark ignition to 100% throttle?
Did you notice any attitude changes in the operation of the engine in different meteorological conditions?
I am a nerd, I think i want to built one of those.
same
You can always purchase directly even if I do not have any ebay auctions going. I am currently boycotting ebays high fees, ridiculous feedback policies, and the extra fees on top of fees.
wolfe1970, not everything is intended for use on a model. check out the 700lb thrust pulse jet video, do you think that guy wanted to strap it to a model?
Is it a possibility that your combustion chamber could explode with more throttle?
P.s. ever try building a jet engine out of a car turbo? Also cool
#2 is definitely a bad idea, as pulse jets work on the principle of pulses which causes a fair amount of turbulance and vibrations that a turbo is not used to and it would thus break quickly.
@pipzipcip2000
I think there's a small hole in the chamber at the back.
Are there any good videos that explain how these work?
@BeckTechnologies makes sense. but how big is the power increase compared to methanol or kerosene?
Cool motor you sound like Tom Green ha 🤣
could you guess how much is the speed of the wind exiting the exhaust? I'm working on a project and I need to know the proximate wind speed generated by almost this size of engine :)
yes it can
does the construction have to be stainless steel? or will mild steel do?
Just out of curiosity, have you ever tried to measure its loudness with a sound level meter?
have a look at exhaust nozzel's (spelling sorry). The correct exhaust will increase thrust.
Know how much heat a car engine and jet engines put out? The flame of a gas turbine can be as hot as 2000 degrees celsius.
Is there any compression of air before it enters the combustion chamber pulsejets?
if so how is it compressed ?
@BeckTechnologies oh okay. Cool man. Hey how much thrust do you think it's putting out?
what about running this off of and in conjunction with woodgas
How much would it cost for a thermo jet a little maller than thisone. Say 6-8lb thrust with the gas intake nozzzles as well?