Wind Tunnel And Numerical Study On The Characteristics Of Wind Speed Distribution In The Roadway With Supporting Structure And Conveyor

Knowledge of wind speed distribution in the roadway is crucial to the study on many aspects of mining industry such as the exothermic law of the rock wall, the settlement of the roadway dust, the migration of gas in the wind flow in coal mine roadway and determination of the gas concentration boundary layer. The former Soviet mine ventilation scientist, Wolonin, and Chinese researchers Yingmin Wang and Chaosong Ji et al. have conducted pioneering work to investigate the wind speed distribution in roadway cross-section, which is extremely important in terms of theoretical development and industrial guidance. However, the cross-sectional shape and supporting form of the roadway are diversed, the roughness of roadway wall is coarse and the roadway is usually filled with various laying equipments and facilities such as the common belt conveyor, mine car. Therefore, the theoretical results of wind speed distribution in roadway mentioned above inevitably has the limitations in the engineering applications where there is a variety of cross-sectional shape and support form. In recent years, with the advancement in computer technology, some researchers used the new computational fluid dynamics approach to do research on the wind speed distribution law of roadway. Modelling using computational fluid dynamics is a new means with a great potential in this area. With the assistance of "Wind Tunnel for Underground Engineering modelling" in Taiyuan University of Technology and a scaled model with similar simulation technology, as well as the corresponding numerical simulation trials, the application of wind tunnel experiments in exploring flow field characteristics of the roadway underground can be handled, and the characteristics of the wind speed distribution under a variety of supporting forms can be achieved with the analysis of the measured data. After experimental analysis, the wind speed distribution for the rectangular roadway supported by bolt, I-beam, and arching is found to be symmetrical, the location of the point with the maximum wind speed in the roadway section protected by three different sticks can be determined. And using data function fitting, the wind speed distribution is found to be logarithmical function in the vertical and horizontal symmetry axes as well as two diagonals. This similar simulation test provides the knowledge of wind speed distribution characteristics in roadway with a variety of supporting forms to the research of the Gas Dynamic Contact, as well as practices in equipment operation and debugging, data measurement and recording in the follow-up study. Meanwhile, this physical modeling provides theoretical and experimental basis for the future research, such as the determination of the thickness of wind boundary layer, the migration law of gas in roadway, the calculation of gas concentration and the characteristics of multi-fluid coupling in the wind boundary layer. This is basic and preliminary work for further in-depth and complex studies.