PIV Experiment And Numerical Simulation Of Jet Ventilation

Jet ventilation is a convenient and reliable ventilation m ethod,which is widely used in engineering,the ventilation without wall of mine and longitudinal jet ventilation of vehicle tunnel are common ways of jet ventilation system in engineering applications,the flow field around the fan and the reasonable distance between tandem fans of the two ventilation ways are studied in this thesis.In this thesis,particle image velocimetry(PIV)and computational fluid dynamics(CFD)are used to experimentalize and simulate the flow field around the fan of the ventilation without wall.The research shows that there is a obvious vortex formation above the airflow in the fan outlet;the ventilation resistance of the tunnel model influences the flow field around the fan;the cyclic air is generated between the outlet and the inlet of the fan,when the ventilation resistance of the tunnel model increases;with the increase of the ventilation resistance of the model the volume of the cyclic air is added.The comparison of the flow field between the numerical simulation and the experiment shows the flow field fit together;the results of the numerical simulation show that with the increase of the ventilation resistance,the gunshot of the fan decreases gradually.Numerical simulation of longitudinal jet ventilation of tunnel is c arried out according to the tunnel prototype and fan model selected in this thesis,the simulation results show that the distance between the fans is too small or too large,the efficiency of fans is reduced;compared with the small distance,the big distance has a greater impact on the efficiency of fans;when the distance is 160 m,the ventilation effect of tunnel is the best and the efficiency of the fans is the highest,so the reasonable distance of fans is 160 m according to the tunnel prototype and fan model selected in this thesis.