J. Phys. IV France
Volume 12, Numéro 7, August 2002
Page(s) 403 - 412

J. Phys. IV France
12 (2002) Pr7-403
DOI: 10.1051/jp4:20020309

Modelling of detonation wave parameters, initiation and hazard of chemically active bubble systems

P.A. Fomin1, K. Mitropetros1, H. Hieronymus1 and J. Steinbach2

1  Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany
2  Technical University of Berlin, 10623 Berlin, Germany

The detonation processes in chemically active bubble systems at high initial pressures are calculated numerically. The dependences of detonation wave velocity at sub- and supersonic regimes of propagation on molar fraction of gas in the mixture and on initial pressure have been calculated for the first time. The Chapman-Jouguet condition for supersonic bubble detonation wave is obtained. The principal possibility for a different detonation wave structure in the case of propagation in the mixture with high initial pressure and longitudinal gradient of bubble volume fraction is predicted.

The dynamics and ignition of a chemically active bubble in a field of external pressure is analyzed. It is shown, that an inert diluent addition can increase the explosion hazard of heterogeneous gas - liquid systems. Calculations demonstrate the possibility of chemically active bubble ignition on the second pulsation. It is shown, that single chemically active bubble ignition is possible also owing to a decompression impulse.

An algorithm for the calculation of thermodynamic parameters of chemically equilibrium hydrocarbon gas with soot particles has been suggested. It is shown, that soot formation can have an essential influence on the dynamics of single bubble in chemically active hydrocarbon-oxygen (organic solvent (liquid) - oxidizer (gas)) heterogeneous systems.

© EDP Sciences 2002