Pulsejet-ram combo

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sockmonkey
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Pulsejet-ram combo

Post by sockmonkey » Sat Dec 07, 2013 4:04 am

There are a few topics here about using a pulsejet as the flameholder for ramjet, but it occurs to me that you don't need the PJ to be the flame holder, you can use the PJ as the flame. The air in a ramjet doesn't need to burn, it just needs to be made hot by the time it goes out the back. You can do it with a heating element and the thing PJs do better than anything is get super hot. Imagine a valved PJ with an aerodynamic shell around it running through the middle of a ramjet body. This simplifies things a lot since you don't have to worry about most of the fiddly bits involved in ramjets.
IIRC the X-jet was supposed to have a full-length shroud. Maybe this is why? You could even add full-length fins to the PJ to maximize the amount of heat dumped into the ram air.
Now I understand there are issues with PJ intakes at such high speed but this issue seems a bit more solvable than getting them to work together in other ways.
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metiz
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Re: Pulsejet-ram combo

Post by metiz » Sat Dec 07, 2013 4:28 pm

Sounds like a plan. build a small thermojet and measure thrust as-is. Slap a shroud around it, blow through it with a leafblower and check thrust again
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sockmonkey
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Re: Pulsejet-ram combo

Post by sockmonkey » Tue Jan 28, 2014 3:42 am

I have since learned that what I proposed is called the Merideth Effect. WWII planes like the P-51 Mustang employed it by making use of the waste heat from the radiator to generate several hundred pounds of thrust from the exhaust duct. So at least I know the principal is sound.
http://en.wikipedia.org/wiki/Meredith_effect

metiz
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Re: Pulsejet-ram combo

Post by metiz » Tue Jan 28, 2014 11:53 am

sockmonkey wrote:So at least I know the principal is sound.
hehehe :D
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luc
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Re: Pulsejet-ram combo

Post by luc » Fri Apr 04, 2014 1:23 pm

Hey guys ...

What about a "Pressure-Ram" combo ... :wink: ... :lol:

:wink:
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Luc
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metiz
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Re: Pulsejet-ram combo

Post by metiz » Fri Apr 04, 2014 3:40 pm

Hey Luc,

Can you upload future videos to youtube and then share the link? The 2mb limit is realy limiting.
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luc
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Re: Pulsejet-ram combo

Post by luc » Fri Apr 04, 2014 4:10 pm

Yeaaaa ... No problems .. I always forget to do this sorry ... :?

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Luc
Designer & Inventor

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