How small can jets get?
Moderator: Mike Everman
How small can jets get?
Hay all!
Im new here and have a question.
How small can you build a jet?
turbojet, pulsejet, ramjet.. whatever..
Does anyone know of a miniture turbojet engine project?
I know about simjets engines.. but i mean small like a banana? :)
A mini radialCompressor turbojet can't be too expensive to build?
Im new here and have a question.
How small can you build a jet?
turbojet, pulsejet, ramjet.. whatever..
Does anyone know of a miniture turbojet engine project?
I know about simjets engines.. but i mean small like a banana? :)
A mini radialCompressor turbojet can't be too expensive to build?
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Re: How small can jets get?
Not much smaller than the smallest in existence right now. It is not so much a matter of technology as of physics. In a jet engine, you have cool air enter the engine, get mixed with fuel, burn, and exit the engine. All those stages in the process require space -- most of all length. Don't expect ever to see a proper jet engine shorter than about a foot long, and even that is achieved so that the gas paths get convoluted rather than straight and it is achieved at the cost of performance.benzo wrote:How small can you build a jet?
The faster a fuel burns, the shorter the engine can be, meaning that the shortest engine you can build will run on hydrogen -- but it brings with it big new technological problems, because hydrogen is expensive and very awkward to handle.
You're wrong. Making it small saves only the amount of material used, which is the least of your worries. The technology remains as expensive as it was and the production procedures for small parts are often more expensive than for big ones. Smaller engines are less efficient, so the cost per pound of thrust goes up as you scale the engine down.benzo wrote:A mini radialCompressor turbojet can't be too expensive to build?
Re: How small can jets get?
Oh ok..
thanx for you quick reply!
thanx for you quick reply!
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Re: How small can jets get?
how small you want it... heres a nice small turbine for ya http://www-mtl.mit.edu/mtlhome/6Res/AR2 ... ilicon.pdf
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Re: How small can jets get?
read mini/micro engines at: http://www.grc.nasa.gov/WWW/AERO/base/rac.htm still in a rush but remember they can be as smal as a button
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Re: How small can jets get?
check out these:
http://www.mech.kuleuven.ac.be/pma/rese ... t_en.phtml
http://www.aip.org/tip/INPHFA/vol-7/iss-6/p20.pdf
pulsejet engines can not be made too small but turbojets can be made extremely small if designed correctly. Also these micro turbines don't necessarily have to be fueled by hydrogen; the newest versions of the silicon turbine will be made to run on hydrocarbon-based fuels.
http://www.mech.kuleuven.ac.be/pma/rese ... t_en.phtml
http://www.aip.org/tip/INPHFA/vol-7/iss-6/p20.pdf
pulsejet engines can not be made too small but turbojets can be made extremely small if designed correctly. Also these micro turbines don't necessarily have to be fueled by hydrogen; the newest versions of the silicon turbine will be made to run on hydrocarbon-based fuels.
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Re: How small can jets get?
So I see, though I must say the physics of this baffles me. Everything I know about fluid mechanics and gas thermodynamics (which is admittedly not much) says this should not be possible. There are so many problems, starting with the length of the flame path, the viscosity of gases etc. that I would never have thought it possible, much less efficient. Those guys are claiming some startling efficiency figures.steve wrote: turbojets can be made extremely small if designed correctly.
Re: How small can jets get?
Perhaps a much more down to earth project for the experimenters, these silicon chip turbines are a tad beyond any of us i think : o)
http://www.technologie-entwicklung.de/G ... kp31_.html
Tom
http://www.technologie-entwicklung.de/G ... kp31_.html
Tom
Experience speaks more then hypothesizing ever can. More-so in chemistry.
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Re: How small can jets get?
Oh, it's a great website; one of my favorites. What do you say to Andreas Petzoldt's 'Monocopter'?
Re: How small can jets get?
Some amazing work, i am really hoping it flys in the end, it would be something to see : oD
Experience speaks more then hypothesizing ever can. More-so in chemistry.
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Re: How small can jets get?
Hi,
Go to http://www.memagazine.org/backissues/fe ... msize.html for an interesting article on a small ( very small ) conventional turbine engine.
Al Belli
Go to http://www.memagazine.org/backissues/fe ... msize.html for an interesting article on a small ( very small ) conventional turbine engine.
Al Belli
Re: How small can jets get?
Thanx for all replys!
Im blown away by some of the links!
Absolutly cool ! ;D
Im blown away by some of the links!
Absolutly cool ! ;D
Re: How small can jets get?
Experience speaks more then hypothesizing ever can. More-so in chemistry.
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Re: How small can jets get?
Those are so cool, Tom. As a manufacturer, I have to say they're a bargain, too.
Mike Often wrong, never unsure.
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