基于多孔环形喷嘴的可燃爆粉尘分散特征的密度效应研究*

为了研究不同密度的可燃爆粉尘在内置多孔环形喷嘴的20 L爆炸特性测试装置中的分散特征，基于负载粒子流方法、耦合DPM动量平衡方程和时间平均 Navier Stokes控制方程组，实现3种不同密度的煤粉、铝粉和锆粉在20 L爆炸测试装置中粉尘分散全过程的数值模拟。研究结果表明:多孔环形喷嘴的分散较为均匀，但是约束管道末端存在局部粉尘残留区，致使爆炸仓内真实粉尘浓度远低于形式浓度；爆炸仓中心位置的最大湍动能随着粉尘密度的增加而减小，只有显著地变化粉尘密度才能展示区分度较高的浓度峰值和抵达浓度峰值的时间。

Study on density effect for dispersion characteristics of combustible and explosive dust based on perforated annular nozzle

To study the dispersion characteristics of combustible and explosive dust with different densities in the 20 L explosion characteristics test device with a built in perforated annular nozzle,based on the particle loaded flow method,and coupling the DPM momentum balance equation and time averaged Navier Stokes governing equations,the numerical simulation on the whole process of dust dispersion for the coal dust,aluminum dust and zirconium dust with three types of different densities in the 20 L explosion test device was realized.The results showed that the dispersion of the perforated annular nozzle was relatively uniform,but there was a local dust residual zone at the end of constrained pipe,so that the actual dust concentration in the explosion chamber was much lower than the normal concentration.The maximum turbulent energy at the center of explosion chamber decreased with the increase of dust density,and the peak concentration and the time to reach it with higher discrimination could be presented only under the significant change of dust density.