| Mine ventilation is a necessary way to dilute and remove the dust?gas and improve the working environment,the change of airflow field in roadway directly influences the movement of gas and dust in roadway.In order to investigate the structure and variation characteristics of air flow field in the heading face during tunneling ventilation,based on similarity principle,the experimental model of driving ventilation tunnel is established,non contact measurement of the flow field in the working face by particle imaging velocimetry(PIV),and the numerical simulation of the flow field of the driving face is carried out by CFD software.Experimental results show that within the effective range of the outlet air flow,changing the velocity of outlet air flow has little effect on the structure of convection field;When outlet wind speed unchanged,with the increase of the distance between the outlet of the air duct and the front face of the tunnel,the position of the vortex region in the flow field moves away from the frontal face gradually;When the distance between the outlet of the air duct and the frontal face is larger than the effective range of the air flow,it has little effect on the change of the convection field structure and the effective range,and in the frontal region of the effective range of the front end of the formation of extremely weak two circulation;the instantaneous flow field can be obtained by experiment,the air flow of the outlet of the air duct is in the process of flowing towards the frontal area,the outlet air flow of the air duct flow to the frontal region in the way of turbulent fluctuation,and produce a lot of small eddy currents.The numerical simulation results are basically consistent with the experimental results,the experimental results provide an experimental basis for the study of the airflow field in the heading face,it is of great significance to study the ventilation efficiency and the dust removal effect of the tunneling ventilation. |
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