Static Ramjet?…

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fastnova
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Static Ramjet?…

Post by fastnova » Fri Sep 04, 2009 9:43 pm

Hi, I could be way off the mark here but is it at all possible to make a ramjet run statically (ie no forward movement or big fan)
I was wandering if you could use an augmenter of some sort to add clean air to the exhaust flow then redirect a portion of the exhaust gasses back to the front of the engine to feed itself, simulating the forward movement it needs to run.

Has anyone thought of or tried this before?

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Re: Static Ramjet?…

Post by Eric » Sat Sep 05, 2009 6:27 am

Search ramjet on youtube, should be the first result.
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Re: Static Ramjet?…

Post by metiz » Sat Sep 05, 2009 8:10 am

fastnova wrote: I was wandering if you could use an augmenter of some sort to add clean air to the exhaust flow then redirect a portion of the exhaust gasses back to the front of the engine to feed itself, simulating the forward movement it needs to run.

Has anyone thought of or tried this before?
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Re: Static Ramjet?…

Post by Eric » Sat Sep 05, 2009 8:52 pm

metiz wrote:
fastnova wrote: I was wandering if you could use an augmenter of some sort to add clean air to the exhaust flow then redirect a portion of the exhaust gasses back to the front of the engine to feed itself, simulating the forward movement it needs to run.

Has anyone thought of or tried this before?
Jonathan
Yup quite a few people. It won't work. Pesky physics!
Thats not.... entirely accurate...
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Re: Static Ramjet?…

Post by metiz » Sat Sep 05, 2009 9:07 pm

fastnova wrote:() simulating the forward movement it needs to run.
Eric wrote: Thats not.... entirely accurate...
I thought it was impossible to use the exhaust from a ramjet to feed itself, whilst remaining static. You MIGHT. be able to "slow down" the forward motion required to properly run a ramjet like fastnova suggests (I think) but, as it looks now (I've seen a pattent and a big discussion why it won't work somewhere here) that won't happen.
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metiz
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Re: Static Ramjet?…

Post by metiz » Sat Sep 05, 2009 9:20 pm

You mean something like this right? if you do:
If the pipe is unmodified (1) you'll get enough speed to maintain a ramjet but not enough oxigen
if the pipe is augmented in between (2) you'll get enough fresh air but since the air cools down the airspeed will go down to, to a point where it will not be enough to power a ramjet
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Re: Static Ramjet?…

Post by ace_fedde » Sat Sep 05, 2009 9:42 pm

Eric,
If you are thinking of your (excellent!) PJ-ramjet set-up as prove against Metiz's statement that a static ramjet is not possible please mind the following:
In your set-up there no static ramjet set-up but a simulated (by the PJ) dynamic set-up. Like a ramjet in a wind tunnel, that's also static, but again not static.
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Re: Static Ramjet?…

Post by Eric » Sat Sep 05, 2009 11:19 pm

What I am talking about has nothing to do with being powered by a pulsejet. I cant go into specifics, maybe in 5 or 6 months.
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Re: Static Ramjet?…

Post by metiz » Sun Sep 06, 2009 8:05 am

Eric wrote:What I am talking about has nothing to do with being powered by a pulsejet. I cant go into specifics, maybe in 5 or 6 months.
It'd be a great technical accomplishment to run a ramjet statical powered by it's own exhaust but what would the purpose of a device like that be?
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Re: Static Ramjet?…

Post by ace_fedde » Sun Sep 06, 2009 10:25 am

metiz wrote: It'd be a great technical accomplishment to run a ramjet statical powered by it's own exhaust but what would the purpose of a device like that be?
Perhaps static take-off? 8)
You don't have to use the feedback all the time, just for take-off.

5-6 months...Long time...
But, very curious!
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krzys Mnich
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Re: Static Ramjet?…

Post by krzys Mnich » Mon Sep 07, 2009 8:10 pm

Here you can find another concept (by Foa) of the static ramjet:
http://www.google.com/patents/about?id= ... =3,046,732
The very tricky "aerodynamic blade" ejector can allow you to obtain the initial pressure. It has, however, one moving part.
The similar device is now developped as a part of air-condition machines.
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krzys

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Re: Static Ramjet?…

Post by krzys Mnich » Mon Sep 14, 2009 8:41 am

krzys Mnich wrote:Here you can find another concept (by Foa) of the static ramjet:
http://www.google.com/patents/about?id= ... =3,046,732
The idea of unsteady-flow ejector ramjet is still alive. In this supersonic ejector ramjet
no moving parts are required
http://www.google.com/patents/about?id=XwIlAAAAEBAJ

At least, my idea of a vortex tube ejector - see
viewtopic.php?f=4&t=3984&start=0#p57483
was invented in the same time by John Minardi and Hans von Ohain:
http://www.google.com/patents/about?id=-xM6AAAAEBAJ
It's not a shame to be preceeded by Hans von Ohain :wink:

I've never heard, however, about any working prototypes of those engines. Did anymody?

regards

krzys

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Re: Static Ramjet?…

Post by Ghrey » Sat Oct 31, 2009 5:17 am

This probably does not count, but,,,,,

I have been tinkering with a sort of pulse to ram design for years now, Nothing working yet, but it could.....

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Re: Static Ramjet?…

Post by paul fellows » Fri Apr 16, 2010 7:41 pm

i posted this viewtopic.php?f=18&t=5785#p69804 in the hybrid section. dose it count.
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Re: Static Ramjet?…

Post by metiz » Fri Apr 16, 2010 8:08 pm

Actually, Eric, It's been almost 7 months - cough up some details! :P
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