20L近球形密闭罐内可燃气体流动和火焰传播的数值模拟

Numerical simulation of combustible gas flow and the flame propagation in 20L nearly spherical and closed tank

采用流体动力学计算软件-FLUENT数值模拟20 L近球形密闭罐进气流场,并分析进气位置、进气速度对进气流场的影响。结果表明:进气流速越大,密闭容器内的压强和气体湍流强度越大;当进气口直径与容器高度比值较小时,罐内压强、速度、湍流强度的最大值都位于进气口的轴线上,轴线左右两边的气体在不同时刻呈相同或相近的流态。模拟了可燃气体爆炸后火焰在罐内的传播过程,得到火焰以点火源为中心,以褶皱球形面向四周扩张,最后对模拟监测的压力值和实验压力传感器采集到的压力值进行比较。直观再现了20 L近球形密闭罐进气时气体扰动状况和近球形密闭罐中心点火的火焰传播过程。

20 L nearly spherical and closed tank was used to test the intake flow field simulated by computational fluid dynamics software-FLUENT.The influences of the different intake locations and the different intake velocities on the flow field were analyzed.Results showed that the faster the intake velocity was,the bigger the pressure and the turbulence intensity was acquired.Moreover,when the inlet diameter was very small compared with the height of the tank,the maximum values of the pressure,the velocity and the turbulence intensity were all on the axis of the inlet.Meanwhile,the left and right gas flows of the axis showed the same or similar flow state.The flame propagation of combustible gas explosion was simulated and some graphs were showed by taking the ignition source as the center.The corrugated spherical flame exploded to the surrounding.Finally,the pressure values were simulated by the software compared with those monitored and acquired by the pressure sensor.The gas disturbing situation had been reproduced when gas intake and the flame propagation of the combustible gas explosion ignited at the tank center in 20 L nearly spherical tank.