COMPUTATIONAL MODELING OF THE GAS-PHASE TRANSPORT PHENOMENA DURING FLAME-JET THERMAL SPALLATION DRILLING

Rock spallation induced by thermal stress can be used to drill through hard rock at high rates. In order to characterize the importance of o perating parameters on rock penetration rate and hole geometry, a mode ling effort was initiated. Because supersonic flame jets are used to i nduce thermal stress in practical spallation drilling systems, a compr ehensive treatment of turbulent gas phase heat, mass, and momentum tra nsport was developed and coupled to a rock mechanics-based model of th ermal stress induced failure. Work reported in this paper provides the mathematical framework, governing equations, and computational algori thms and compares model-predicted results to experimental data when po ssible.