Experimental study on wind-fog coupling dust suppression technology in tunnel drilling and blasting operations based on CFD numerical simulation

Using a combination of numerical simulation and experimental research, the optimal parameter setting scheme of wind-fog coupling dust removal technology was determined to solve the problem of tunnel dust pollution. Firstly, the diffusion laws of the tunnel gas flow field, dust field and droplet clusters were analyzed by constructing a numerical model. Secondly, through the construction of the experimental platform, the nozzle atomization experiment and spray dust reduction experiment were carried out, and the results show that the optimum spray parameters for a single airflow field are nozzle caliber 0.3 mm and spray pressure 5 MPa. Then, an experimental study of wind-fog coupled dust reduction under variable airflow field was carried out by orthogonal method. The influence degree of different factors on the dust reduction efficiency was ranked as follows: wind speed (A) > nozzle caliber (B) > spray pressure (C). The optimal parameter configurations for the two evaluation metrics of total dust concentration and inhalable dust concentration were summarized: A4B2C4 and A4B3C4. Finally, a robust multiple linear regression model was developed in this study. Experimental validation shows that the prediction error of the model is within 5 %.