On the Sensitivity of the Maximum Explosion Pressure of a Dust Deflagration to Turbulence

Abstract

The maximum explosion pressure of a deflagration is often regarded as a thermodynamic quantity and it is believed to be insensitive to the flow conditions of the combustible mixture involved. While this is true for premixed gases, the present work demonstrates that the opposite is the case when powder-air mixtures are ignited to deflagration. In order to illustrate this disparate behavior, experiments were conducted with methane-air and cornstarch-air mixtures of a fixed fuel to air ratio, at varying turbulence levels. The maximum explosion pressure of cornstarch-air mixtures was observed to increase by a factor of 1.5 when the turbulence level of the dust cloud was varied. An explanation for this behavior is proposed by considering the effect of turbulence on the liberation of volatile matter from the particles.