Influences of roadway cross-section variation on outburst shock wave propagation

In order to analyze shock wave propagation of coal and gas outburst induced by roadway cross-section variation,firstly,mathematic model of outburst shock wave propagation in variation cross-section roadway was established by fluid dynamics and air dynamics,the variation law between shock wave propagation and cross-section variation rate were obtained by theory analysis.Secondly,the experimental system for shock wave propagates in variation cross-section roadway was constructed,and the shock wave propagation law was revealed.The experimental results indicate that overpressure becomes larger and the energy per area of the wavefront is increased when shock wave propagates form large cross-section to small one.Then numerical simulation model of shock wave propagate in variation cross-section was established,the simulation results show that the greater the initial shock wave overpressure is,the faster the shock wave decay,and the larger the roadway cross-section variation rate is,the greater the shock wave attenuation coefficient is.Finally,comparative analysis shows that the theoretical analysis,experimental research and numerical results are consistent.