Research On Propagation Characteristics Of Shock Wave And Gas Flow From Gas Outburst And Induced Catastrophic Law Of Mine Airflow

In order to deeply study the propagation characteristics of shock wave and gas flow as well as the catastrophic characteristics of mine airflow induced by coal and gas outburst, firstly, propagation characteristics of shock wave and gas flow in different type roadway is studied by theory analysis, experimental research and numerical simulation;then the unsteady catastrophic model of mine airflow is established when the power of outburst disappeared, the model is solved by programming, the catastrophic law of mine airflow in upper ventilation and downward ventilation when gas outburst occuring are analyzed by the program. Finally, the reliability of research results is validated by existing coal and gas outburst case. The results show that, in straight roadway, attenuation of shock wave overpressure with distance meets the exponential relationship, the velocity of gas migration is slower than the speed of shock wave; the intensity of shock wave decays in intersection of roadway, more energy flows to the main roadway; when shock wave and gas flow propagates form roadway with big cross-section to small one, per energy of wave front increases; For the roadway with bend, when the bend angle of roadway increases, the attenuation coefficient decreases. In upper ventilation, in order to prevent airflow reversal of the side branches, the main fan should be in normal operation and resistance should be increased in the branch with gas pressure. In downward ventilation, gas pressure induces airflow reversal in the branch with gas existing, the airflow reversal does not occur in side branches; the higher the pressure of main fan is, the shorter time the airflow backs to the steady; less time is needed for exhausting gas in upper ventilation than diluting gas in downward ventilation. The research results have important theoretical and practical significance for outburst disaster aid, disaster ventilation as well as effectively preventing the occurrence of secondary disasters.