[AR] Re: mixed monoprops (was Re: DARPA responsive launch challenge)

  • From: Terry McCreary <tmccreary@xxxxxxxxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Fri, 27 Apr 2018 21:28:14 -0500

Perhaps something other than CO2 might be fruitful here. Halons work, not by smothering the fire but by reducing production of radicals involved in flame propagation. If the chemical mechanism--the step-by-step sequence of molecular collisions--of the N2O-C2H2 reaction is known, perhaps an additive could be found that interferes with the rate-determining step.

There are at least two problems that I can think of, right off the bat. First, that additive would almost certainly interfere with the desired reaction in the combustion chamber.  Second, the decomposition of acetylene into its elements is a spontaneous reaction (delta-G of formation is positive). If an additive that would prevent that from happening was known, it would probably already be in use in acetylene used for welding.

Best -- Terry

On 4/27/2018 12:10 AM, Troy Prideaux wrote:

There may be problems where CO2 freezes or evaporates out of solution prior
to the nitrous, but presumably there are worse problems with acetylene
coming out of solution with pressure/temperature.
I can't see acetylene coming out or CO2 for that matter. Nitrous is a very 
effective solvent for organics. The partnership with something like acetylene 
will be quite an intimate affair and I just can't see CO2's pacification role 
producing anything other than a subtle reduction in explosive yield when the 2 
energetic compounds inevitably get down and boogie.

Troy


--
Dr. Terry McCreary
Professor of Chemistry
Murray State University
Murray KY  42071


Other related posts: