Research On The Propagation Weakening Mechanism And Numerical Simulation Of Mine Outburst Shock Wave Under Elastic Device Bufferin

Coal and gas outburst is a major disaster which causes more casualties and high frequency in coal mine accidents,and also easily causes secondary disasters such as airflow disorder,short-time reversal and gas explosion in coal mine roadway ventilation system.Therefore,the propagation energy of coal and gas outburst is regarded as a kind of unexpected energy,and the propagation of mine outburst shock wave is attenuated artificially to the safety threshold as far as possible.It is of equal importance to prevent and reduce casualties and property losses caused by outburst accidents.Based on the existing application of accidental propagation energy transfer and release devices and the principle of flexible cushioning of airbags,this paper proposes a weakening mode for the propagation energy of outburst shock waves under the cushioning condition of elastic devices.Taking the protruding shock wave as the research object,the elastic device was innovatively developed as the shock wave buffer and energy reduction device installed in the roadway.Based on the theory of aerodynamics and hydromechanics and mine tunnel system analysis,the attenuation law of propagation energy of outburst shock wave under elastic buffering is studied.The elastic device model and the mathematical model and numerical calculation model of propagation characteristics of outburst shock wave under elastic buffering are established.The energy weakening mechanism and propagation law of outburst shock wave along straight roadway under elastic buffering under different outburst pressure and elastic device size are numerically simulated.Through the research of this paper,the main research achievements are as follows:1)According to the propagation characteristics of coal and gas outburst shock wave,the formation and propagation characteristics of outburst shock wave were analyzed,and the mathematical model of outburst shock wave propagation energy in roadway was established.The results show that the attenuation degree of the mine outburst shock wave energy is mainly related to the outburst pressure,the work done by coal powder transportation and the cross-sectional area of roadway.The outburst pressure is positively correlated with the overpressure of shock wave propagation,and the cross-sectional area of roadway is the most effective way to artificially weaken the energy of the shock wave.The design of elastic device produces elastic cushioning and energy reduction effect on shock wave while changing the cross-sectional area of roadway.2)An elastic device is developed to ensure the safety of life and property underground.The elastic device consists of a spring assembly,a baffle and an air bag pad.The elastic device is simple in structure and easy to maintain.Based on the reflection effect and elastomer characteristics of spring assembly,baffle and airbag cushion,the mechanism of weakening the propagation of outburst shock wave by spring assembly,baffle and airbag cushion was analyzed,and the cushioning and energy reduction mechanism of elastic device was clarified.3)Based on the propagation of outburst shock wave in elastic buffer and energy reduction device,a numerical model of outburst shock wave propagation along straight roadway under elastic buffer was established by using ANSYS finite element numerical simulation software.The buffer efficiency of elastic device is calculated by different outburst pressure and different size of elastic device.The results show that the secondary acceleration of the superimposed reflection shock wave and outburst incident shock wave under elastic buffering causes the local energy in the space before and after the cross-section of the elastic device to increase,but the overall energy is weakened,which reduces the propagation distance of outburst shock wave.