The role of the gas compression-conduction mechanism in shock initia¬tion of granular materials was studied by analyzing the dependence of grain surface temperature on the magnitude of the shock and the relative sizes of grain and surrounding volume of interstitial gas. A temperature of the shocked interstitial gas computed by a one-dimensional, two-shock model serves as initial gas temperature condition for the heat conduction problem of a spherical cold grain in a spherical shell of hot gas enclosed in a semi-infinite solid cold spherical wall. Initial and maximum temperature of the grain surface, and the time at which the maximum is reached, are com¬puted. Results of the heat conduction solution are correlated in terms of dimensionless parameters, and are applicable over a range of material properties, initial gas pressures, initial hot gas and cold solid tempera¬tures, and grain and gas shell sizes. It is shown that at one atmosphere initial ambient pressure the mechanism can be a contributing factor to initiation if particle size distribution or particle irregularity leads to the existence of small particles surrounded by large, gas-filled spaces;the required sizes are possible for real materials. At low pressures (~10 i Hg) on the other hand, it is unlikely that the mechanism is a contributing factor. Since in practice these granular masses can be shock-initiated independent of initial ambient pressure, the conclusion is that at least one primary initiation mechanism other than gas compression-conduction plays a role.
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