1961 (a) (b) Figure 120: (a) Full and (b) zoomed cross-section views of the 3D tetrahedral mesh, from the central "finer" blasthole, to yellow boundary layers and then growing outward. Modelling results The open blasthole was modelled over 16 hours to show the effect of convective cooling from air. A modest reduction in wall temperature resulted with significant upwelling of warm air above the selfheating seam and almost no air movement below it. The air flow and temperature gradients are shown in Figure 121 with notable temperatures reported in Table 46. Figure 121:Plot of temperature over time for an open blast-hole scenario with a heat flux (Q) of 45 W/m2 generated by self-heating coal seam
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