Thermal shock assisted percussive drilling: A numerical study on the single-bit axisymmetric case
Research output: Contribution to journal › Article › Scientific › peer-review
|Number of pages||18|
|Journal||International Journal of Rock Mechanics and Mining Sciences|
|Publication status||Published - 2020|
|Publication type||A1 Journal article-refereed|
Rock fracture is described in the continuum sense by a damage-viscoplasticity model with separate damage variables for tensile and compressive failure types. In the numerical simulations, an axisymmetric numerical rock is dynamically indented with a spherical tool in cases of intact and heat shocked heterogeneous rocks. In realistic simulations with an initial borehole, the heat shock treatment of rock enhances the mechanical breakage, increasing especially the tensile damaging, in unconfined and confined conditions with and without down-the-
hole pressure. However, according to the simulations, down-the-hole pressure effectively prevents the thermal spallation phenomenon crucial for thermal jet drilling.