www.pulse-jets.com

OK. Using Forrest's Form we have: dfr = f/fn : dfr = Driving Frequency Ratio f = Pipe (driving) Frequency fn = valve frequency We have: Tharratt: dfr = 0.8 P. Schmidt: dfr = 0.33' or dfr = 0.2 Alright, this asks the question "is fn the free reed frequency"? This isn't the place for this discussion. ...

H Grim. Here is an interesting difference of opinion! I found these some time ago. They are recommended set-ups for valved motors Nf = Pipe Operating Frequency Nr = Reed Frequency Tharratt: Nf/Nr = 0.8 P. Schmidt: Nf/Nr = 0.33' or Nf/Nr = 0.2 Graham. P.S. I've lost the source of this information so ...

I want to maintain some level of dignity and for a few minutes appear I know what I'm talking about. Hi. Ha, Forget the Dignity. The mechanical simplicity of these motors hides a horrible complexity. They all have a habit of doing the unexpected when you don't want them to. We all have stories but ...

Hi Grim. Will your motor run, without forced air, on Propane? If it will then the pipe and valves are probably OK and you can be sure that it's the pressure drop across the fuel system that's the problem. If the motor runs on Propane, try sleeving down the induction cone. This will increase the air ...

Hi Charles. Yes, it is a bit of a macro Fest! Start by reading everything here. I have posted some instructions. Be sure to update the major programmes with the Public Release 2. It's a whole lot better. I have a much faster version here with lots of good bits but get this running first. Open the Co...

Hi As part of the NUDiS download package in the Tools section I have modelled a Type 06 motor with 100mm dia combustion chamber. The Type 06 model starts up easily and in the real world should run well statically. The Thrust is not spectacular but will improve with forward speed. The Induction plug ...

Hi. When it's running, you could try feeding some fuel, via a Rosscoinjector, into that exhaust pipe, just to see what happens? My one concern is the amount of cold air drawn into the exhaust pipe. In ordinary designs it's this mass of air that provides the majority of the thrust. With this design y...

Where are the Dims?
Sorry mate.

Graham.

Dear Mike. I have a feeling that your exhaust cone should be a little shorter but should first run this motor through NUDiS. If your happy would you send me the as constructed dims and I'll model it. I'm a little perplexed that it should run for ten seconds then stop. it's not going out of tune as i...

Mr Jim Bamford (http://www.onthewire.co.uk/bamford.htm) developed a boiler for his flash steam hydroplane. From the Book Experimental Flash Steam, J.H. Benson and A.A. Raymond. Tee Publishing. I Quote "The 'Bamford' venturi-type boiler is undoubtedly the most efficient steam generator yet devised fo...

Hi Bill and Joe.
Take a look at the Snecma - AS1. For That matter it's not too far from the TYPE06 either. They are probably doing much the same thing.

Very nice bit of work Mike.

Graham

Good work! Glad to hear you got it going. Intake and Exhaust internal diameter is as important as the length of these pipes. Perhaps it's better to say that the internal diameter and length of the pipes are related. If your happy that the lengths of the pipes are correct look to the diameter of the ...

Good Morning.
'Kentfield' et al, did some work and made some comments concerning multiple intakes. Later 'Bill' duplicated this work, I think his results are on the forum somewhere?

Graham.

Please see this Topic. http://www.pulse-jets.com/phpbb3/viewtopic.php?f=3&t=2021&start=0&st=0&sk=t&sd=a Here you see the FWE as made by James D. He is using spark ignition ! To quote James D "The FWE is built to the dimensions given by Larry in his jetzilla article, 1.25" tailpipe and 26" total leng...

Thanks, Graham! ---- and try some tail expansion. The acoustic length, intake length and throat location are in the same places. Dear Mike. A good place to start. going from straight exhaust to expanded tail does not seem to be quite linear; you may have to move a little either side of this length!...