Ramjet = pulseengine?

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Robin
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Ramjet = pulseengine?

Post by Robin » Wed Jul 19, 2006 10:54 pm

Hello! Does a ramjet has a continiued flow of gas like a jetengine, with differens that the ramjet uses speed (outside pressure) to "charge" it or does it work like a pulse jet.. 2-stroke = suck,squeze then bang and blow.

Sorry for the terrible grammath and spelling.. Im from sweden ;)

Mvh

Mark
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re: Ramjet = pulseengine?

Post by Mark » Thu Jul 20, 2006 12:16 am

According to Foa, subsonic ramjets benefit from pulsating combustion. He says the line of demarcation between a subsonic ramjet and valveless pulsejet is blurred. Frog/toad moth/butterfly alligator/crocodile type of thing.
Mark
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Najm
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re: Ramjet = pulseengine?

Post by Najm » Thu Jul 20, 2006 5:35 am

Don't valvelesss pulsejets also benefit from the ram effect when they are moving through the air?
Even if a subsonic ramjet has pulsating combustion but no resonance is ocurring so it can't be regarded as a true pulsejet engine.
According to Foa, subsonic ramjets benefit from pulsating combustion
How do ramjets benefit from pulsating combution?

multispool
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re: Ramjet = pulseengine?

Post by multispool » Thu Jul 20, 2006 10:48 am

It's probably little to do with resonance, more likely a cycling phomenon of the burning pattern, some of the old miniature turbines gave a quiet pulsing sound when the compressor was surging, probably much the same thing going on. Whether it's disirable in a sub-sonic ramjet, i have no idea!

Mark
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Re: re: Ramjet = pulseengine?

Post by Mark » Thu Jul 20, 2006 12:56 pm

Najm wrote:Don't valvelesss pulsejets also benefit from the ram effect when they are moving through the air?
Even if a subsonic ramjet has pulsating combustion but no resonance is ocurring so it can't be regarded as a true pulsejet engine.
According to Foa, subsonic ramjets benefit from pulsating combustion
How do ramjets benefit from pulsating combution?
Mixing. I'll see if I can find the paragraph. Does anyone out there in pulsejet land have Foa?
Mark
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Mark
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re: Ramjet = pulseengine?

Post by Mark » Sat Jul 22, 2006 2:14 am

Thanks Ben. The paragraph mentions the line of demarcation bit about valveless pulsejets and subsonic ramjets being blurred... Also it talks about the subsonic ramjet benefitting from pulsating combustion.
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Mark
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re: Ramjet = pulseengine?

Post by Mark » Sat Jul 22, 2006 1:47 pm

Thanks for digging that up Ben.
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