On the sensitivity of the maximum explosion pressure of a dust deflagration to turbulence

The maximum explosion pressure of a deflagration is often regarded as a thermodynamicquantity and it is believed to be insensitive to the flow conditions of the combustiblemixture involved. While this is true for premixed gases, the present workdemonstrates that the opposite is the case when powder-air mixtures are ignited todeflagration. In order to illustrate this disparate behavior, experiments wereconducted 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 mixtureswas observed to increase by a factor of 1.5 when the turbulence level of the dust cloud wasvaried. An explanation for this behavior is proposed by considering the effect of turbulenceon the liberation of volatile matter from the particles.