Fuel injection and sparkplug placement???

[Bruno Ogorelec]

Is that named for THE Viv Collins, reclusive and understated combustion scientist? renowned Pressure Jet enthusiast???

As a midwife at the birth of that device, I can proudly confirm that, yes, the top-secret Collins Collar was sired by Vivian Collins, Esq. It was one of the few things that actually worked in the early stages of BCVP development.

[Mark]

I have a thesis or two and anyway one graduate student utilized a ring with a multitude of holes drilled in the annular ring to feed the pulsejet, and he also did some trombone studies with sleeving, or jacketing the tubing to feel his way to the highest thrust.
Mark

[NanoSoft]

My jet still will not sustain itself. I followed the plans exactly as milisavljevic told me and it don't work.

It helped some but i think the problem is now in the fuel injection. Spring Break is coming so i will try to experiment alot then but until then any pictures of working injection systems and any ideas are welcome.

It seems that when i first get the jet warmed up the combustion happens right were it did before but after i run it for about 1 minute the combustion moves to the comustion chamber a little more. The entire exhaust turns yellow and the combustion cahmber turns red which is actually a big improvement over the last time

Heres another pic.
Thanks to all who have commented.

[Viv]

Is that named for THE Viv Collins, reclusive and understated combustion scientist? renowned Pressure Jet enthusiast???

As a midwife at the birth of that device, I can proudly confirm that, yes, the top-secret Collins Collar was sired by Vivian Collins, Esq. It was one of the few things that actually worked in the early stages of BCVP development.

It would appear that I have been outed! as it were:-)

Viv

[Mark]

Here's some variation on a theme to our annular ring topic. In my thesis by some fellow that used an annular ring, it occurs to me that he not only used a single hollow ring with holes, but up to three rings, held on hollow stems, shaped like some child's plastic bubble blowing ring with stem. He was using this in the throat of a valved pulsejet I think. It's been awhile since I read the thesis.
Anyway, here is this company's idea. There might be patents on this philosophy that go back a 100 years I would imagine. In a way even Reynst uses an annular ring to subdivide the incoming fuel.

http://www.popularhotrodding.com/engine ... notbigger/

Mark

[Mark]

Just a note, in the carburetor link, if you scroll down about 2/3 of the page it brings up that the annular ring inflicts a very small flow penalty.
Mark

[Mark]

To simplify, speak from experience or speak from conjecture. There, I have said it, that what separates those that know and those that think they know.
Mark

Boy, I sure sound cranky after rereading my post. I suppose the crux of the disgruntlement comes from having something simple in theory, explained as if it were a breeze to bang out, but not breezy enough to want to do it yourself, or perhaps the idea is so fabulous you can't patent it for fear of losing any hope of monetary gain from ankle biters.
Annular injection may be the best way to go, if you need to pay the price in extra parts/labor for a specific design to work.
Instead of the annular ring, I have often wondered how a spiracle fuel/air philosophy would work.

aol://4344:1708.D0066305.40174342.672606019

What you would do is catch a large fat grasshopper, tie him down with thread and place him under a microscope. Then focus on his squid-like variable diameter pulsating thorax and note the respiration design, a linear row of holes essentially, air carburetor intake chambers on either side of his thorax. From there you would have to figure a way to apply your "spiracles" concept to the inside of your pulsejet. Or maybe you could just drill simple or complex holes in the sides, akin to a Logan side porting, evoling into a creature with supernumerary ports, in some way similar how scientists can cause at will Mr. Grasshopper's antennae to grow and mutate into legs instead, in the lab.
Maybe you could get by with just three simple and easily installed fuel injectors dispersed around the perimeter of your pulsejet and get the same results. There is probably little under the sun that hasn't been tried, (or talked about).
Mark

[Viv]

To simplify, speak from experience or speak from conjecture. There, I have said it, that what separates those that know and those that think they know.
Mark

Boy, I sure sound cranky after rereading my post. I suppose the crux of the disgruntlement comes from having something simple in theory, explained as if it were a breeze to bang out, but not breezy enough to want to do it yourself, or perhaps the idea is so fabulous you can't patent it for fear of losing any hope of monetary gain from ankle biters.
Annular injection may be the best way to go, if you need to pay the price in extra parts/labor for a specific design to work.
Instead of the annular ring, I have often wondered how a spiracle fuel/air philosophy would work.

aol://4344:1708.D0066305.40174342.672606019

What you would do is catch a large fat grasshopper, tie him down with thread and place him under a microscope. Then focus on his squid-like variable diameter pulsating thorax and note the respiration design, a linear row of holes essentially, air carburetor intake chambers on either side of his thorax. From there you would have to figure a way to apply your "spiracles" concept to the inside of your pulsejet. Or maybe you could just drill simple or complex holes in the sides, akin to a Logan side porting, evoling into a creature with supernumerary ports, in some way similar how scientists can cause at will Mr. Grasshopper's antennae to grow and mutate into legs instead, in the lab.
Maybe you could get by with just three simple and easily installed fuel injectors dispersed around the perimeter of your pulsejet and get the same results. There is probably little under the sun that hasn't been tried, (or talked about).
Mark

Ok Mark I have worked out what the problem is! you just need to get more ventilation in that garage workshop of yours.

Its the methanol fumes! I cant think why I didn't spot it sooner, here I was thinking you had a smoking habit of awe inspiring proportions for all these years and all along it was just the methanol vapours getting to you.

Still easy to cure old mate just open the window, but maybe you will need to come down gently, maybe just start by opening it a little or small window or fan light maybe.

And let this be a warning to all you newbe pulse jetters out there, methanol realy mucks you up so don't do it!

Viv:-)

[Mark]

Ok Mark I have worked out what the problem is! you just need to get more ventilation in that garage workshop of yours.

Viv:-)[/quote]


Well yes, it's not always nitrous oxide jolly good fun out there in the world of pulsejet building. Many get disgusted and quit after 6 months trying to build a pulsejet, one of my humorous magazine articles says about the hobby. Of late it has been acetylene and MAPP gas that have been getting into my system. It is said they have a kind of garlic odor to them, and now I fear that the gases are beginning to smell slightly like fried oysters. What do you make of that?
One thing I have found though, experience comes with a price, one of them being irritability at times, and too I have been traumatized by endless theories, and Murphy's Law and his corrolaries.
Perhaps a cup of chamomile tea would help, not that I have any on hand. I had a good dose of acetylene again today, it sure isn't fussy about running rich or lean in my valveless Logan, going way up and way down in sound level as I turned the flow knob back and forth, bored with the effect after several repetitions. What to do now, what next?
I urge everyone to try some hands-on shovel digging if you aren't already, oh the humanity!
Mark

[NanoSoft]

Help me. i need plans or pictures of working liquid fuel injectors for valveless pulse jets. Please help.

[resosys]

Help me. i need plans or pictures of working liquid fuel injectors for valveless pulse jets. Please help.

I think Hinote is the only person on this forum that has done that with a valveless pulsejet. His being a Kentfield 4 pipe.

I've been gathering the parts to do this in my shop, but haven't strapped anything together yet.

How are you pressurizing your fuel? How much control do you have over the pressure?

You may want to take a look at some misting heads for those outdoor misting systems used to keep human type mammals cool during the summer. You may have to mount them so they mist fuel into the intake tube, near the combustion chamber in order to get adequate mixing.

At least, that's how I'd start out. That and make sure I had a good amount of control over the pressure in the system so that I had some granular control of how much fuel is being injected.

It'll take a fair amount of voodoo as well.

I probably haven't been much help. Good luck.

Chris

[jmhdx]

There's no photo, I haven't made one; there are plenty already; no findings, I am lazy, and busy, and my name is Mike Sargent.
If I had to make one of every design or concept or modification I'd be 95 before I had photo's worth taking. Thanks to this site you can decide which technologies are worth persuing and which are fundamentally incorrect for your specific usage. I'll go see if there's a theory page.

May I wish any Irishmen well.

[Mike Everman]

OK, so I got an e-mail from you a while ago, and your name then was "Mark Sturgeon". I like "Mike Sargent" better, for what it's worth. I am not sure what to think, Mike, Mark, jmhdx, ????? Bruce?? Oh, god, you're not IVAR are you???? Naw, too civil.

[milisavljevic]

DELETED.

[Gary Robinson]

PS: As you have read, few here have succeeded with liquid fuels. You are about to "join the club". ;-)


Hi again good peoples and newbeings.
I have to agree that liquid fuel isnt the easiest way to go. It is much more viable to get an engine running on propane and then dabble once you know you have a working unit.
I have tried stick type nozzles and circular ring dispersement tubes over the last few years with propane, each with some degree of success. I also have a double sleeved inlet tube that functions similar to the Collins collar but failed to achieve a place in terminology history like Viv's creation.
I have tried to use a mix of diesel and petrol in a Lockwood design and may well have succeded but for the failure of the fuel injector due to lack of cooling. Basically, the swizzle stick came adrift and dumped over a litre of fuel mix in, in less than 2 seconds while the engine was humming away on propane. The engine never stalled but it did 'bog' down quite a lot and the resulting football field sized black cloud was an awesome sight as it ascended silently into the cloudless blue sky, much in a horizontal rather than vertical mass.
The method I used to contain the fuel mix was as simple as it gets.
I had a small rechargeable fire extinguisher which was 3/4 filled with fuel mix and then pressurised with compressed air. The outlet fitting had a small and very cheap regulator on it, (much like a thumbscrew control on a spray gun) and terminated to a hose that connected to the spray bar. Simply pulling the lever on the extinguisher released the fuel mix upon demand.
I do have a quantity of various types of electric pumps here, vane, diapraghm and centrifugal, but decided to go the compressed air method to comply with the self containment and simplicity ideals that we strive for in our pulsejet designs.
My advice to you Mr Nanosoft (after you comply with that of Mr Milisavljevic) is to whack copious amounts of high speed air through your engine and add fuel till you get some sort of result. You can decrease (balance) the air input as the fuel begins to fire. Also, introduce the air through a small (3mm or so) nozzle and direct it at the wall of the intake tube to get a swirl thing happening.

Now my self induced exile is completed I hope I can rejoin the learning curve we all share in common.

Happy hydrocarbon consumption.