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From :  Mark
Date :  2002-01-24 10:43:21
Subject :  Mini Myers Initial Tests comment and digression
Larry Cottrill wrote :

>
>
>CONCLUSION -
>
>Based on very preliminary test observations made on an admittedly crude model, I feel that there is reasonable evidence that a working engine can be derived from Myers' design. I still believe that optimization for a carbureted design is possible; however, someone with liquid fuel injection or propane fueling capabilities should try a small model that is somewhat larger and which more strongly resembles the original Myers pattern.
>
>Comments from everyone are welcome, of course.

L Cottrill

I would use a larger sized duct for testing because hunting for compression and perky fuel/air ratios becomes more forgiving when you scale up from a miniature version. And first, I would try the original design and then muck with it to see how that alters its behavior postively or negatively. Try using some of the 1 and 1/2 inch diameter pipe instead of the tiny stuff. I use conduit tubing on occasion like yourself and it is really one way to make a brass tacks inexpensive puslejet bar none. I think once I paid about $2.25 for a ten foot section and the one inch diameter stuff is only around $5.00 for ten feet.
And for that matter threaded water pipe is very convenient for experimentation too. That's what the inventors of the Dynajet used when they first started toying with the idea of making a smaller pulsejet after being taken with the V-1. I don't know of an easier way to quickly make a pulsejet for so little cost and time. With the bell reducers you can quickly neck up or down and the bell shape has a fairly acceptable flare to it. For ~$15 dollars several years back I made a screaming loud Dynajet-sized engine out of 2 inch and 1inch threaded water pipe connected with a bell and one other bell for the head or intake. The only thing I had to make was the valve and valve plate which was just a 2 inch flat washer which rested on the lip of a winding or two of thread I sawed off the end of the 2 inch pipe and screwed into the head bell.
And really, the thing is heavy, but with a stubby spark plug threading into the combustion chamber, the little guy looks quite nice in some quirky way. I put a smaller bell ( 1 inch by 1 and 1/4) on the tail to add a flare tail too. I gave it to my teenage nephew and he started it up with his friends where he lives in Chicago.
Anyway, the makers of the Dynajet wrote that it (The Dynajet) was a failure with a capital F in the money making department. Too bad so many puslejets out there are just a little too expensive for many people to buy. Think how many more Dynajets could have been sold if the cost were to have been brought down in some way. Many people don't need the state of the art pulsejet, they would just like to have one that runs. I mean how many times to you want to make that much noise anyway? Piston engines far surpass pulsejets in thrust/fuel consumption, quietness and vibration, reliability, and in many cases that other little detail--cost. Just look at the two Dynajet inventors or for that matter Bruce Simpson. Noone is getting rich that I know of.
Mark




Mini Myers Initial Tests -- Long Post (2002-01-23 12:25:39)
   Re:Mini Myers Initial Tests -- Long Post (2002-01-23 13:33:02)
     Re:Mini Myers Initial Tests -- Long Post (2002-01-23 14:33:27)
       Re:Mini Myers Initial Tests -- Long Post (2002-01-23 15:22:51)
         Re:Mini Myers Initial Tests -- Long Post (2002-01-23 16:19:07)
           Re:Mini Myers Initial Tests -- Long Post (2002-01-23 16:45:41)
   Re:Mini Myers Initial Tests -- Long Post (2002-01-23 18:17:41)
     Re:Mini Myers Initial Tests -- Long Post (2002-01-24 05:59:41)
         Re:Mini Myers Initial Tests -- Long Post (2002-01-24 06:11:02)
   Mini Myers Initial Tests comment and digression (2002-01-24 10:43:21)
     Re:Mini Myers Initial Tests comment and digression (2002-01-24 12:09:24)
           Re:Mini Myers Initial Tests -- Long Post (2002-01-24 13:22:31)
           Re:Mini Myers Initial Tests -- Long Post (2002-01-24 16:07:29)
       Re:Mini Myers Initial Tests comment and digression (2002-01-24 18:26:38)
       Re:Mini Myers Initial Tests comment and digression (2002-01-24 19:19:21)