Platonized propellant

It was soon realized that platonized propellants, with their reduced temperature sensitivity in the plateau- and mesa-burning range, could be effectively used to minimize the sensitivity of the performance of a rocket to the temperature of the environment. Much work has been devoted to understanding the mechanism of plateau and mesa burning, with a view to optimizing the performance characteristics of rocket motors. 

Experimental results indicate that various phenomena occur on platonized propellants.When lead catalysts are added to high-energy double-base propellants, no super-rate burning occurs. Lead catalysts only act effectively on low-energy double-base propellants. On the other hand, lead catalysts are known to retard the rate of aldehyde oxidation. Carbonaceous materials are formed on the burning sur-... 

Fig. 8.22 The luminous flame front of the platonized propellant approaches the burning surface more rapidly than that of the non-catalyzed propellant when the pressure is increased in the plateau-burning pressure region.

Fig. 6.22 A typical burning rate profile of a platonized double-base propellant.

Fig. 6.23 Burning rates of catalyzed NC-NG and NC-TMETN double-base propellants, showing two platonized regions for both propellants resulting from the addition of a combination of two lead compounds.

Kubota, N., Ohlemiller, T. J., Caveny, L. H., and Summerfield, M., Site and Mode of Action of Platonizers in Double-Base Propellants, AIAA Journal, Vol. 12, No. 12, 1974, pp. 1709-1714 see also Kubota, N., Ohlemiller, T. J., Caveny, L. H., and Summerfield, M., The Mechanism of Super-Rate Burning of Catalyzed Double-Base Propellants, 15 th Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA, 1973, pp. 529-537. 

Low-frequency oscillation in a rocket motor depends on the pressure exponent of propellant burning rate and the free volume of the chamber. [ -7] when a double-base propellant composed of nc(0 510), ng( - 55), and dep(0.120), with pbsa(0.015) as a platonizing catalyst, bums in a strand burner, the burning rate characteristicsmay be divided into four zones, as shown in Fig. 13.14. The pressure exponent varies between the pressure zones n = 0.44 in zone I above 3.7 MPa, n= 1.1 in zone II between 3.7 MPa and 2.1 MPa, n = 0.77 in zone III between 2.1 MPa and 1.1 MPa, and n = 1.4 in zone IV below 1.1 MPa. 

Cobalt stearate, salicylate and acetyl acetonate etc. Promising platonizers and catalysts for DB Propellants [247]. 

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