Simulating Vented Maize Starch Explosions in a 236 m3 Silo

The paper describes computational fluid dynamics (CFD) simulations of a series of large-scale dust explosion experiments performed in a 236-m silo. Mechanical suspensions were generated by pneumatically injecting maize starch into a 22 m high silo. The experiments included tests with injection from the bottom and from the top of the silo, but the present study only considers bottom injection. The clouds were ignited at various heights above ground. The same experiments have been simulated previously, but the current work involves an updated version of the CFD code and explores the effect of grid resolution on the simulation results. The results from the simulations are in good agreement with the experimental data, and confirm the observation that the reduced explosion pressure in long slender silos is very sensitive to ignition location. The simulation results highlight the effect of dust distribution within the silo, and reproduce the characteristic pressure oscillations, with frequency in the range 4-7 Hz, observed in some of the tests.

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