J. Phys. IV France 10 (2000) Pr11-99-Pr11-107
On the possibility to modify the performance of propellant mixtures used in RAMAC by addition of metallic particlesB. Veyssière1, W. Ingignoli1 and B.A. Khasainov2
1 Laboratoire de Combustion et de Détonique, UPR 9028 du CNRS, ENSMA, 1 avenue Clément Ader, BP. 40109, 86961 Futuroscope cedex, France
2 Semenov Institute of Chemical Physics, Russian Academy of Sciences, ICP, ul.Kossiguina D4, 117977 Moscow V334, Russia
To explain the experimental results obtained in the 30 mm Ram accelerator at ISL, showing that in the subdetonative mode, the terminal velocity of magnesium projectiles at the end of Ramac tube is higher than the CJ detonation of the propellant gaseous mixture, whereas the projectile undergoes a mass loss during the propagation, the assumption is made that metallic particles ablated from the projectile react with the gaseous species and modify the performances of the propellant mixture. The problem is examined by comparing experimental and calculation results in an analogous situation of fine aluminum particles suspended in hydrogen-air mixtures. It is demonstrated that the classical thermodynamic model is unsuitable for explaining correctly the experimental observations. Prediction of changes in performances of the propellant mixture requires that two-phase flow effects be taken into account. These changes depend on the mass concentration, size and shape of the solid particles.
© EDP Sciences 2000