From: billn@hpcvaac.cv.hp.com (bill nelson)
Newsgroups: rec.pyrotechnics
Subject: Re: Liquid Fuel Rockets
Date: 13 Oct 92 16:28:15 GMT
Article-I.D.: hpcvaac.1992Oct13.162815.17359
Organization: Hewlett-Packard Company, Corvallis, Oregon USA

farb@ecr.mu.oz.au (William_Cuming FARROW) writes:
: >>
: >>You don't want to play with hydrazine.  Really, you don't, especially
: >>considering the rather crude, leaky apparatus you are describing.
: >>Don't take my word for it; look it up in Sax.
: >>
: >>Caveat detonator.
: >>
: >>-- 
: >>Mike Van Pelt                          Here lies a Technophobe,
: >>mvp@netcom.com                            No whimper, no blast.
: >>mvp@hsv3.lsil.com                      His life's goal accomplished,
: >>                                          Zero risk at last.
: 
: Thank you kindly for sharing your superior wisdom with a novice such as
: myself. Your penetrating insight and instant critical evaluation of my    
: humble construction astounds me. Amateurs such as myself feel obliged to 
: document their every claim, but your concise appraisal transcends this.
: Your helpful criticism and suggestions for the future will benefit my future
: works. I have seen the error of my ways, and, based on your advice, will
: substitute an alternative for hydrazine - nitroglycerine :) perhaps? ;)

Your sarcasm is uncalled for. Mike is right about the hydrazine - it is
nasty stuff. Also, from what I have seen of your design, it is not anywhere
near being strong enough. Note that he suggested that you check Sax for
the hazards. That sounds like someone who is willing to research and learn
as much as they can to minimize risks. It is far better than designing a   
contraption on the back of an envelope and deciding that it is good enough.

Some things just appear to be foolish, without in depth analysis. For
example, why do the needles from the syringes go in the right hand side?
That appears to be the exhaust nozzle, not the combustion chamber. Maybe
you could provide more detail - probably written. ASCII graphics are a
pain.

The fuels to be used are the least of your problems. Liquid fuel rocket
design is not simple. There are a couple of groups who have been working
on such motors for several years. I believe there is a group there in OZ.

: >There are safer hypergolic fuels than hydrazine. Heheh... Not much safer
: >though. You may wish to look into Furfural alcohol and fuming nitric acid.
: >
: Where can I get hold of Furfural alcohol, and how can I stop fuming nitric 
: acid from burning holes in the syringes? Glass ones are a little heavy.

Maybe you are starting to see the problems involved with liquid fuels? 
Containers and plumbing tend to be high grade stainless steel. Pumps or
high pressure air tanks are needed for fuel feed to keep the rate constant,
otherwise you tend to get oscillations that often destroy the engine.

: >rvassar@terapin.com
: 
: Oh well, back to the drawing board. Life in a library sounds fun and
: stimulating, any more helpful criticism is welcome,
: Billy Boy

Better than keeping silent and having someone, who are obviously not as
knowledgeable as you, try duplicating your design and maiming or killing
themselves. At least we can warn others that it is stupid. What you do
with the information is up to you - it is your life. 

Bill