CFD simulations of turbulent fluid flow and dust dispersion in the 20 liter explosion vessel

Abstract

A CFD model was developed with the aim at simulating the turbulent flow field induced by dust feeding and dispersion within the 20 L bomb, and the associated effects on the distribution of dust concentration. The model was validated considering a set of data (pressure time histories and root mean square velocity) available in the literature. The time sequences of velocity vector and kinetic energy maps have shown that multiple turbulent vortex structures are established within the sphere. These vortices generate dead volumes for the dust which is pushed toward the walls of the sphere. The obtained results are relevant to the practice of dust explosion testing and the interpretation of test results and, then, they should be taken as reference to improve the conditions for standard tests. �� 2013 American Institute of Chemical Engineers

A Review of the Fire and Explosion Hazards of Particulates

“…Finally, Di Benedetto et al 108) accomplished a CFD study to simulate the dust dispersion in the 20-liter explosion vessel. The dust concentration variation in time and space after its injection into this vessel, being the standard test equipment used by many, is still unknown.…”

CFD modeling and simulation of turbulent fluid flow and dust dispersion in the 20-L explosion vessel equipped with the perforated annular nozzle

“…In all cases, the velocity vectors exhibit an asymmetric distribution. The asymmetric behavior has to be addressed to the effect of the particle sedimentation on the fluid flow, as also suggested by Kartushinsky et al [16] and as also shown in our previous paper [9].…”

“…The turbulence decay starts few milliseconds after the opening of the valve -well before the end of the feeding phase -due to the decrease of the pressure gradient and the related source term ( સ×સ୮ మ ) in the vorticity equation [4,9].…”

“…More recently, we performed CFD simulations of both the fluid and the particle flow evolution inside the 20-liter vessel equipped with the rebound nozzle [9][10][11]. We showed that the turbulent flow field has a strong spatial distribution and, thus, the propagating flame encounters different turbulence levels along its path.…”

“…They addressed the difference to the reduction in particle size that occurred during dispersion. On the other hand, our CFD results have shown that, in the presence of the rebound nozzle, the dust distribution inside the vessel is rather non uniform, as the dust particles are not able to enter the core of the vortical structures generated [9], whatever the dust concentration [10] and diameter [11].…”