Numerical Simulation of Particulate Matter 2.5 Distribution in a Roadway

Large amounts of dust particles pose serious hazards to the health and safety of China's coal miners during roadway blasting processes. It is known that among these dust particles, Particulate Matter 2.5 (PM_2.5) does the greatest amount of harm. In order to study the distributions of the PM_2.5 in roadway blasting processes, a mathematical model of the gas-solid two-phase flow was established in this study, which was based on a Direct Simulation Monte Carlo Method (DSMC). Then, a multiphase flow program was developed. This study's results indicated that following the blasting processes, fine dust particles gradually floated up and were suspended for long durations in the underground roadway space. The medium-sized dust particles slowly sink to the ground and were eventually expelled before settling to the floor of the roadway. The coarse particles were rapidly settled to the roadway floor. It was determined that the PM_2.5 particles in the front end of the dust group could not be quickly diluted, and the concentrations were high until it is expelled from the roadway, whereas the PM_2.5 dust particles in the back end of the underground roadway were found to be gradually diluted. Eventually, the PM_2.5 concentrations exhibited an alternating thin to dense phase distribution. When compared with the Particulate Matter 5 (PM₅), it was found that the PM_2.5 was more difficult to discharge, and easily formed serious PM_2.5 dust air pollution. This study's results were determined to be conductive to the future control of PM_2.5 in the underground roadway blasting processes.