PulseJet starting problem

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MorningStar
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PulseJet starting problem

Post by MorningStar » Tue Oct 04, 2011 1:12 pm

Hello everyone!!!!

I am a mechanical engineer college student from Greece and - as you may have guesed until now- i am building a Valveless PulseJet engine, Lockwood style.
The problem is that it doesn't start. It cannot maintain combustion on it's own...
So, first things first: The dimensions

Intake tube: Φ90χ300mm
combustion chamber: Φ200x300mm
the exhaust tube : Φ63,5 - 500mm straight (horizontal), 90o bend , 400mm straight (vertical), 90o bend, 1,1m straight (horizontal)

I am using a big leaf blower and a compersor that generates 8 bars of pressure.
The fuel is propane from a stock 'bootle' that everyone can find.

When i open the fuel, i have ignition and plenty of flame while i am blowing air into it. But it cannot maintain the combustion on it's own adn when i am taking the air away...nothing.

Can you please help me???? I have tried everything!!! Maybe the exhaust tube is small diameter wise? Do i need a 'cone' on the exhasut tube in order to suck air better? More than one propane tank? PLEASE EVERYBODY TELL WHAT YOU THINK IT WOULD BE A GREAT HELP!!! I REALLY NEED TO FIX IT BECAUSE IT'S A PROJECT I AM MAKING FOR THE COLLEGE IN ORDER TO FINISH IT!!!

Thank you for your time!!!
SV

ganuganu
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Re: PulseJet starting problem

Post by ganuganu » Tue Oct 04, 2011 2:12 pm

i think the problem is with your design and fuel tank..

so first your combustion chamber is 200mm dia with 300mm length thats a smaller length when compared to the size of your cc.. so try to make the 200mm dia with 400mm length..

secondly try to use the exhaust dia between 96 to 100mm try to decrease the first horizontal pipe length from 500 to 340mm.

thirdly try to use a 15 or 20kg propane tank for fueling your engine.

MorningStar
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Re: PulseJet starting problem

Post by MorningStar » Thu May 10, 2012 12:28 pm

Can anyone else try to help me? After all this time i'm still having the same problem!!

PyroJoe
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Re: PulseJet starting problem

Post by PyroJoe » Thu May 10, 2012 2:20 pm

What are the current dimensions? Are they the same as before?

Mike Everman
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Re: PulseJet starting problem

Post by Mike Everman » Thu May 10, 2012 6:37 pm

Do you have a pic or video?
This is a big motor. It will not run on gas alone from a small tank. You will have to flip the tank over so you are sending it liquid propane. You cannot have a regulator or tiny restrictor hole in your tank supply fittings.
Mike
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