The simplest pulsejet ever

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PulseDuuude
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Re: The simplest pulsejet ever

Post by PulseDuuude » Thu Sep 16, 2004 11:57 pm

Viv wrote:We should get Kenneth to allow html file posting so we can post the vuiewable interactive file.

Viv
Viv,

You can post the eDrawing html file if you first convert it to ZIP...as I did in this thread.


Proposed No-Weld Logan
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Re: The simplest pulsejet ever

Post by Viv » Fri Sep 17, 2004 12:10 am

PulseDuuude wrote:
Viv wrote:We should get Kenneth to allow html file posting so we can post the vuiewable interactive file.

Viv
Viv,

You can post the eDrawing html file if you first convert it to ZIP...as I did in this thread.


Proposed No-Weld Logan
Good point but i wanted it to work in the window right off the back like:-)

Viv
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Re: The simplest pulsejet ever

Post by Bruno Ogorelec » Fri Sep 17, 2004 12:19 am

You can do it now by uploading an image file to the website, writing its url in the text where you want the image to appear and bracketing it with [img]and[/img] tags. I did it in the FAQ section with "How Does the Valveless Pulsejet Work". Works nicely. The problem is that the thing then repeats those same images at the bottom of the text, which looks stupid.

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Re: The simplest pulsejet ever

Post by Mike Everman » Fri Sep 17, 2004 3:53 am

Perhaps you can put the photos in your personal gallery, then put that URL?
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Re: The simplest pulsejet ever

Post by Bruno Ogorelec » Fri Sep 17, 2004 5:52 am

Mike Everman wrote:Perhaps you can put the photos in your personal gallery, then put that URL?
Stupid me! I never thought of that! Jesus, sometimes I'm really slow witted....

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Re: The simplest pulsejet ever

Post by Ray(in England) » Wed Dec 15, 2004 3:53 pm

Bruno and others,
How would this design work if the air intake gap were facing towards the open exhaust end, as opposed to facing the closed end?.

As it stands wouldn't the ignition blasts blowing forwards partly cancel out the thrust from the exhaust end?.

Thanks, Ray.

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Re: The simplest pulsejet ever

Post by Bruno Ogorelec » Wed Dec 15, 2004 4:12 pm

Ray, there is no reason why anything should blow forward. The front part of teh engine is a closed chamber. Its opening faced downstream. Hot gases will blow downstream. The air slit is to the side of the hot gas stream. Frankly, I see no way for thrust to be exerted in any direction but rearwards.

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Re: The simplest pulsejet ever

Post by Ray(in England) » Fri Dec 17, 2004 3:41 pm

Thanks Bruno,
If I ever make a p.j.,it will be this one,your design,so I might one day see what happens at the air intake.
Ray.

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Re: The simplest pulsejet ever

Post by Ray(in England) » Fri Dec 17, 2004 3:54 pm

Bruno,

Please just confirm I've understood your below instruction correctly.
By 'half diameter' do you mean sawing a slit which is a quarter of the tube's circumference long?.As opposed to sawing a slit of half the circumference's length?.



'About four diameters from the plugged end, saw the tube across to perhaps half diameter with a hacksaw or whatever.'

Thanks, Ray.

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Re: The simplest pulsejet ever

Post by Bruno Ogorelec » Sat Dec 18, 2004 4:50 pm

Ray(in England) wrote:Bruno,

Please just confirm I've understood your below instruction correctly.
By 'half diameter' do you mean sawing a slit which is a quarter of the tube's circumference long?.As opposed to sawing a slit of half the circumference's length?.



'About four diameters from the plugged end, saw the tube across to perhaps half diameter with a hacksaw or whatever.'

Thanks, Ray.
Ray, if the tube is, say, 4 inches in diameter, and you plug one end, mark a spot about 16 in from the plugged end and start sawing the tube across at that point. Don't saw it all the way through, but only halfway -- to the depth of two inches or thereabouts.

Mind that no one has built such an engine before to the best of my knowledge. God only knows how easy (or difficult) it will be to get to work. Good luck!

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Re: The simplest pulsejet ever

Post by Ray(in England) » Fri Jan 07, 2005 7:19 pm

Bruno, et al.
I read your comment in another topic about how the California's have proved u correct in your advocating gas fuel fed through the air intake.
Do u think this would work in your 'simplest' valveless pj. design?.
Or is it best to stick to your diagram layout?.
Thanks, Ray.

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Re: The simplest pulsejet ever

Post by Bruno Ogorelec » Fri Jan 07, 2005 7:42 pm

Ray, I would be wrong in advocating anything specific here. The problem is that I think such a fuel feed makes great sense, and have arguments in its favor, but in actual practice few designers have used it. I don't know why. It could well be that some factor I am not aware of works against it. I just don't know. I wish I could investigate this and find out.

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Re: The simplest pulsejet ever

Post by Nick » Sat Jan 08, 2005 1:27 pm

mmm, since the early bcvp days eh?, that is a long time ago :-)
Sounds good though, now to find some appropriate sized pipe!.

Nick

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Re: The simplest pulsejet ever

Post by Mike Everman » Sat Jan 08, 2005 3:53 pm

Bruno Ogorelec wrote:Ray, I would be wrong in advocating anything specific here. The problem is that I think such a fuel feed makes great sense, and have arguments in its favor, but in actual practice few designers have used it. I don't know why. It could well be that some factor I am not aware of works against it. I just don't know. I wish I could investigate this and find out.
My experience with it was early, like my first fuelling attempt. I now know it was not successful because the diameter and location are important and can't just be TLAR, at least my TLAR. And it could have been that it was a stinger in the slit-like smashed Kazoo intake, and partly that it shouldn't be hand-held. Bill hit it dead on with his stinger.
Mike Often wrong, never unsure.
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