Effect of surface microstructure on the temperature sensitivity of burning rate of ammonium perchlorate

Kishore, K and Sridhara, K (1997) Effect of surface microstructure on the temperature sensitivity of burning rate of ammonium perchlorate. In: Defence Science Journal, 47 (2). pp. 177-184.

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Abstract

Considering Vielle's law and the new thermodynamic model which the authors have developed recently, the true dependence of temperature sensitivity of burning rate (sigma(p)) of ammonium perchlorate (AP) on pressure is resolved and experimentally verified for pellet burning. The value of sigma(p) decreases with pressure steeply in regime I' (below 20 atm), but gently in regime I (above 20 atm). The sigma(p) value of powder AP has been determined and it is observed that sigma(p(powder)) > sigma(p(pellet)), which clearly suggests that sigma p is influenced by the surface temperature sensitive parameter (partial derivative T-s/partial derivative T-o)(p) and hence by the surface/subsurface microstructure. In powder burning, the buoyant lifting of the particles into the gas phase occurs, which constitutes the so-called 'free board region' (FBR) extending just above the true surface. Consequent to the decomposition of AP particles in FBR, the condensed phase heat release gets curtailed and sigma(p(powder)) becomes larger. A general relationship for sigma(p) in terms of density and surface temperature is suggested, which is applicable to both pellet and powder AP.

Item Type:	Journal Article
Publication:	Defence Science Journal
Publisher:	Defence Scientific Information Documentation Centre
Additional Information:	Copyright of this article belongs to Defence Scientific Information Documentation Centre.
Department/Centre:	Division of Physical & Mathematical Sciences > Mathematics
Date Deposited:	02 Jun 2009 10:09
Last Modified:	12 Nov 2018 15:44
URI:	http://eprints.iisc.ac.in/id/eprint/18904

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