(1 首都经济贸易大学管理工程学院，北京 100083;2 北京科技大学土木与资源工程学院，北京 100083)
(1 School of Management and Engineering, Capital University of Economics and Business,Beijing 100083,China; 2 School of Civil and Engineering, University of Science and Technology Beijing, Beijing 100083, China)
Recently, air curtains, as a device to effectively isolate easily diffused dust, have been frequently used in mining and tunneling construction process where more dust is produced, while a uniform air curtain will bring better dust isolation effect. Fluent numerical simulation combined with similar experimental methods were used to analyze the effect of changes in the diameter of the air curtain and the air duct structure inside the air curtain on the uniformity of the air curtain, and the air curtain designed to supply air uniformly was installed in the actual construction of the tunnel model to simulate and analyze the effect of its dust insulation.Results show that: the diameter increases, the airflow axial inertia force inside the air supply device decreases, which gives sufficient time to change the outflow direction. Meanwhile, the axial static pressure of the air curtain device is more uniform to form a more homogeneous air curtain. However, the influence of the diameter change on the homogeneity of the air curtain is not linear, i.e., there exists a critical diameter, which makes the improvement of the homogeneity of the diameter continue to increase insignificantly, and the range of the diameter of the air curtain increases with the increase of the length of the air supply device.On the basis of the air curtain device with a length of 1m and a critical diameter of 180mm, after installing the wedge-shaped fan-shaped blocking body with a calculated arc height of 149.9mm according to the principle of air duct design, the average pressure gradient inside the air curtain device was reduced from 38.4Pa/m to 19.3Pa/m, and the uniformity of the outlet wind speed was increased from 87.6% to 93.2%, and the uniformity of the air curtain was significantly improved;Finally, after installing the air curtain, the rebound dusty airflow in the dust isolation area was blocked, and the airflow in the area became chaotic and complex with increased vortex, and the dust retention time was increased to allow a longer time for the relatively large dust particles to settle. The dust concentration in the whole dust isolation area increased significantly, and the effect of air curtain dust isolation is remarkable.