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Old 10-06-2017, 07:27 AM
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blackshire blackshire is offline
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Location: Fairbanks, Alaska
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Quote:
Originally Posted by Jerry Irvine
I have made PVC Arcite propellant motors for the military for space borne uses. Had my motors not been summarily decertified by TRA without cause and without the legally prescribed burn down period in about 1993 I would have started making our then certified nozzle less motor with a variant of Arcite and later reloadables would follow along.

CTI uses a thermoplastic and they have a production capacity several times that of Errortech as a result.

cite:
http://v-serv.com/usr/motors/H90nozzleless.htm
http://v-serv.com/usr/NAR-TRA-93.2.htm
Your bureaucratically-blocked, plastic propellant hobbyist rocket motors gave me a few ideas (which I'll get to below), but first:

To "Physician, heal thyself" should be added the admonition, "Regulators, regulate thyselves" (before even *considering* regulating others--the recent stupid Food and Drug Administration ruling, that a bakery couldn't list "love" as one of their products' ingredients, is a case in point...). PVC Arcite--that sounds like one of Atlantic Research Corporation's solid propellant formulations (if it is, TRA's action was even more senseless, as such a "recipe" is surely very well proven after so many years and motor firings). Even NASA's (it may have been the N.A.C.A., soon before it became NASA) Wallops station had developed a successful case-less--and also nozzle-less--solid rocket motor (its slow-burning fiberglass case "burned down" along with the "propellant-formed, shallow cone nozzle," leaving just the payload after burnout). Also:

Good for CTI--such a rigid, yet cast-able, thermoplastic propellant has production and manufacturing consistency advantages over case-bonded (or "liner tube-bonded") synthetic rubber-based propellants. Your PVC plastic propellant could also have other applications:

Formulated ^without^ an oxidizer, it could be used in hybrid rockets and in solid-fuel ramjets. If produced with just enough oxidizer to keep it burning without air (if made very "fuel-rich," that is), the propellant could be used in solid-fuel ramjet/ducted-rocket motors (the low oxidizer content would keep it lit--and thus eliminate flame-outs--when the airflow through the motor was momentarily reduced or became turbulent, such as during sharp turns and similar maneuvers. (This "fuel-rich" characteristic would also make it useful for hybrid rockets whose liquid oxidizers were lower in oxygen than LOX or nitrous oxide, by "making up for" the oxidizers' lower concentrations of--or more strongly-bonded--oxygen.) As well:

By *purposely* using a rather "anemic" solid oxidizer, your plastic propellant would be a safe and effective propellant for use in Jetex/Jet-X/Rapier-type F/F (Free-Flight) and even micro R/C (Radio-Control) model jet planes. Such long-burning, relatively low-thrust jet motors (which might also benefit from your nozzle-less feature, as there would be no nozzle to potentially fail) could be made single-use (a rolled paper, forward-plugged casing might be ideal [the Rapier jet motors are also single-use, forward-plugged paper-cased units, see: http://www.google.com/search?q=rapi...1.0.-ZX0fUY9szI ]) or reusable. (Such "RMS jet motors" could be similar in arrangement to re-loadable composite propellant rocket glider motors, as the jet motors--like the rocket glider motors--would also have no delay or ejection charges). Also like the Rapier jet motors, plastic propellant jet motors could be made in end-burning and core-burning variants, to enable different thrust levels, burning times, and jet model flight characteristics.
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