Burning rate augmentation

The acceleration force in the radial direction acting on the solid particles, is represented by 

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Composition Variables on Acceleration-Induced Burning-Rate Augmentation of Solid Propellants , NASA TND-6923 (1972) 13) G.W. 

Iron compounds are common catalysts for ammonium perchlorate propellant systems, and burning-rate augmentation is a strong function of catalyst surface area and shape. 

Fig. 11.15 shows the level of burning rate augmentation, defined according to =... 

Fig. n.15 Burning rate augmentation as a function of pressure for B-AP pyrolants containing different mass fractions of boron particles. 

Fig. 11.16 Burning rate augmentation as a function of the total surface area of the boron particles in B-AP pyrolants composed of boron particles of different sizes.

Fig. 11.17 shows burning rate augmentation, Eb, as a function of the adiabatic flame temperatures of B-AP and Al-AP pyrolants. The incorporahon of aluminum particles into a base matrix composed of AP-CTPB pyrolant increases Ej. However, the effect of the addihon becomes saturated for adiabahc flame temperatures higher than about 2500 K. On the other hand, the incorporahon of boron particles into the same base matrix increases Eg more effectively, even though the adiabahc... 

Kuwahara, T., and Kubota, N., Role of Boron in Burning Rate Augmentation of AP Composite Propellants, Propellants, Explosives, Pyrotechnics, Vol. 14,1989, pp. 43-46. 

Fig. 13.31 Burning rate augmentation of an NC-NG double-base propellant and an AP-CMDB propellant along silver wires.

Fig. 13.32 Effect of silver wire diameter on burning rate augmentation of an AP-CMDB propellant.

Tq, of gas-generating pyrolants such as fuel-rich AP-HTPB and fuel-rich nitropoly-mer pyrolants are lower than those of rocket propellants such as AP-HTPB and nitropolymer propellants. The gas-phase temperature is low and hence the heat flux feedback through the wires is low for the gas-generating pyrolants as compared with propellants. However, r /ro appears to be approximately the same for both pyrolants and propellants. The obtained burning-rate augmentations are of the order of 2-5. 

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