Numerical Investigation of Rock Breaking Mechanisms by High Pressure Water Jet

Many factors and complexities are involved in breaking rock with a high-pressure water jet, which has made it difficult to explain the rock breaking internal mechanisms. This in turn has constrained the applications and development of water jet technology. In this work, we use numerical simulations to analyze the influence of jet incidence angle, jet velocity, nozzle diameter, number of jets, transverse velocity, and rock physical properties on the rock breaking efficiency. This has important practical implications for future research on rock breaking with high pressure water jet, as well as for the applications of water jet technology. For example, we established that there are two threshold pressures in the process of water jet rock breaking in our model. When the jet pressure becomes greater than the first threshold pressure, the rock breaking mechanism is erosion mainly through water wedging, and when the jet pressure exceeds the second threshold, the rock breaking mechanism is hammer punch dominated by water hammer effect.