Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Archivum Combustionis

Powiadomienia systemowe

Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Numerical modelling of coal mine explosion

Klemens R., Kosinski P., Wolanski P., Korobeinikov V. P., Markov V. V., Menshov I. S., Semenov I. V.

Archivum Combustionis

2001

Vol. 21 nr 1

71-79

The investigation of unsteady processes behind shock waves propagating in a gasdust combustible mixture is very important to understand mechanisms of industrial dust explosions like those in coal mines. In the paper, two aspects of this study are considered. The first one concerns questions related to ignition and burning of the mixture, where some results are given of numerical investigation of the transition to detonation process. Also 2D structure of unsteady detonation in the mixture of coal particles with air is taken into consideration. In the applied model, the moving medium is treated as a two-phase, two-velocity and two-temperature continuuum with mechanical and thermal interaction between the phases. Devolatilization, gas-gas and gas-particle exothermic chemical reactions, radiation and heat conduction are also taken into account. The other aspect is the problem of the dust enhancement and dispersion from the dust layer behind a shock wave. The forces caused by particles rotation and gas vorticity are taken additionally into account. Two numerical methods were developed to solve numerically the considered problems. Examples of calculations are presented.

Direct initiation of detonation in hydrogen - air mixture by decomposition of low pressure domain without energy input

Levin V.A., Markov V.V., Zhuravskaya T.A.

Archivum Combustionis

1998

Vol. 18 nr 1-4

125-133

The problem of a direct initiation of spherical detonation in stoichiometric hydrogen - air mixture without any external energy input but only as a result of a decomposition of a low pressure ball domain is under consideration. The investigation of a converging flow with taking into account the detail mechanism of chemical reactions is done by a finite-difference method based on the Godunov's scheme with a moving difference grid and explicit separation of the leading shock and the contact surface. The calculations fulfilled under different values of low pressure ball radius and under different values of low pressure inside the ball shows that even for atmospheric pressure in the external space the self-sustained detonation wave may arise after reflection from the centre of symmetry. It is obtained that some minimal critical radius of the ball domain under which the detonation is realised exists for every fixed low pressure.