Double base propellant burning mechanism

Kubota, N., Ohlemiller T.)., Caveny, L. H., and Summerfield, M., The Mechanism of Super-Rate Burning of Catalyzed Double-Base Propellants, AMS Report No. 1087, Aerospace and Mechanical Sciences, Princeton University, Princeton, NJ (1973). 

Since the burning surface temperature, T, is dependent on the regression rate of the propellant, it should be determined by the decomposition mechanism of the double-base propellant. An Arrhenius-type pyrolysis law represented by Eq. (3.61) is used to determine the relationship between the burning rate and the burning surface temperature. 

In an attempt to understand the combustion mechanism of catalyzed double-base propellants, several investigators have conducted experiments to measure the burning rates of strands of liquid nitrate esters. The various measurement techniques were very similar to that employed in a conventional solid propellant strand burner. The liquid esters were placed in a tubular container, and the liquid surface regression speeds were measured by optical methods or by the fuse-wire method used in solid-propeUant strand burners. The only important difference between the solid and the liquid strand burning-rate measurements is that the liquid strand burning speed is very much dependent on the diameter of the container. 

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. 

Ishihara, A., and Kubota, N., Erosive Burning Mechanism of Double-Base Propellants, 21 St Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA (1986), pp. 1975-1981. 

Refs 1)F. Daniels, "The Mechanism of Powder Burning , OSRD Rept3206(Jan 1944) la)B.L. Crawford et al, Observations on the Burning of Double-Base Propellants , OSRD 3544(April 1944) 2)O.K.Rice, "The Theory of Burning of Double-Base Rocket Powders , OSRD Rept 5224(June 1945) 2a)O.K. Rice, "The Theory of the Burning of Rocket Powders , OSRD Rept 5574(Nov 1945) 3)B.L. Crawfotd et al, "Studies on Propellants , OSRD Rept 6374(1945) 4)Summary Tech Rept of Div 8, NDRC, Vol 1(1946), 90-95 5)S.F. Boys ... 

The data reported in the literature suggests that the replacement of DEP by Bu-NENA in the Dense NC/NG+ DEP/AP/AI/RDX-based composite modified double-base (CMDB) propellants results in increase in the burn rate by 18-20% at 70 kg cm pressure. The calorimetric value and percentage elongation also increase significantly. Further, thermal stability and sensitivity of such propellants are comparable with DEP-based CMDB propellants [184]. Bu-NENA is also a component of low vulnerability ammunition (LOVA) propellants [185, 186]. The introduction of butyl-NENA into SB, DB and gun propellants results in improvement of their mechanical properties and energetics and reduction in their sensitivity [187]. 

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