Double-based propellants analysis

One extremely important point to realize is that different propellant types may have different rate-controlling processes. For example, the true double-base propellants are mixed on a molecular scale, since both fuel and oxidizing species occur on the same molecule. The mixing of ingredients and their decomposition products has already occurred and can therefore be neglected in any analysis. On the other hand, composite and composite modified-double-base propellants are not mixed to this degree, and hence mixing processes may be important in the analysis of their combustion behavior. 

The temperature profile in the combustion wave of a double-base propellant is altered when the initial propellant temperature Tq is increased to Tq -i- ATq, as shown in Fig. 6.15. The burning surface temperature is increased to -i- AT, and the temperatures of the succeeding gas-phase zones are likewise increased, that of the dark zone from Tgto Tg-t- ATg, and the final flame temperature from 7 to Tf-t- ATf If the burning pressure is low, below about 1 MPa, no luminous flame is formed above the dark zone. The final flame temperature is Tg at low pressures. The burning rate is determined by the heat flux transferred back from the fizz zone to the burning surface and the heat flux produced at the burning surface. The analysis of the temperature sensihvity of double-base propellants described in Section 3.5.4 applies here. 

Kubota, N and Ishihara, A., Analysis of the Temperature Sensitivity of Double-Base Propellants, 20th Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, PA (1984), pp. 2035-2041. 

Addnl Refs (Limited Distribution) A) A.T. Camp, Research, Development and Large-Scale Application of Temperature-Independent Double-Base Propellants A Brief Survey and History , IHSP 68-14 (1968) B) R.M. Abbott N.S. Gelber, Analysis of Lead and Copper Salts of Hydroxy-Substituted Benzoic Acids , PATR 4376 (1972)... 

C.E. Kirby, Flameless Combustion Mechanism of M-2 Double-Base Propellant , NASA Tech Note TND-6105 (1971) CA 74, 143953 (1971) [The author reports on the heat of reaction for the flameless combustion of M-2 double-base proplnt (NG 20, NC 77, and other ingredients 3%) detd at 2,07-1380kN/m2 by the use of differential scanning calorimetry and thermogravimetric analysis. The heat of reaction... 

Table 21.2 Analysis of Double-Based Propellants (NC, NG present)...

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