MODELING OF JETFLOW DRILLING WITH CONSIDERATION OF THE CHAOTIC EROSION HISTORIES OF PARTICLES

A general model is presented for the simulation of a drilling process by abrasive waterjet. The conventional constitutive equation for the e rosion rate of a single particle penetrating into a solid target is ex tended and applied to millions of particle strikes, taking into consid eration their erosion histories. The theoretical advancement of this m odel reflects the inherent damping effect that occurs as the depth of drilling increases. Particles involved in erosion are divided into cat egories according to their kinematic features, and their penetration p erformances are evaluated individually. A particle-laden jetflow with chaotic behavior, which was constructed previously by the authors, is employed to coordinate the positions of particles and describe their v elocities and how rates, including laminar and turbulent flow with the average scale. The high accuracy of the theoretical results is verifi ed by independent experiments of drilling glass, titanium and other ma terials. (C) 1997 Elsevier Science S.A.