Fire and explosion accidents are frequently caused by combustible dust, which has led to increased interest in this area of research. Although scholars have performed some research in this field, they often ignored interesting phenomena in their experiments. In this paper, we established a 2D numerical method to thoroughly investigate the particle motion and distribution before ignition. The optimal time for the corn starch dust cloud to ignite was determined in a semi-closed tube, and the characteristics of the flame propagation and temperature field were investigated after ignition inside and outside the tube. From the simulation, certain unexpected phenomena that occurred in the experiment were explained, and some suggestions were proposed for future experiments. The results from the simulation showed that 60–70 ms was the best time for the dust cloud to ignite. The local high-temperature flame clusters were caused by the agglomeration of high-temperature particles, and there were no flames near the wall of the tube due to particles gathering and attaching to the wall. Vortices formed around the nozzle, where the particle concentration was low and the flame spread slowly. During the explosion venting, particles flew out of the tube before the flame. The venting flame exhibited a “mushroom cloud” shape due to interactions with the vortex, and the flame maintained this shape as it was driven upward by the vortex.

易燃粉尘经常引起火灾和爆炸事故，这引起了人们对该领域研究的兴趣。尽管学者们对该领域进行了一些研究，但他们在实验中常常忽略了有趣的现象。在本文中，我们建立了二维数值方法来彻底研究点火前粒子的运动和分布。确定了半封闭管中玉米淀粉粉尘云点火的最佳时间，并在管内外点火后研究了火焰传播和温度场的特性。通过仿真，解释了实验中发生的某些意外现象，并为以后的实验提出了一些建议。模拟结果表明，粉尘云点燃的最佳时间为60–70 ms。局部高温火焰簇是由高温颗粒的聚集引起的，并且在管壁附近没有由于颗粒聚集并附着在壁上而引起的火焰。喷嘴周围形成漩涡，颗粒浓度低，火焰蔓延缓慢。在爆炸过程中，颗粒在火焰之前从管中飞出。排出的火焰由于与涡旋的相互作用而呈现“蘑菇云”的形状，并且当火焰被涡旋向上推动时，火焰保持该形状。由于颗粒聚集并附着在管壁上，因此在管壁附近没有火焰。喷嘴周围形成涡流，在喷嘴处颗粒浓度低，火焰蔓延缓慢。在爆炸过程中，颗粒在火焰之前从管中飞出。排出的火焰由于与涡旋的相互作用而呈现“蘑菇云”的形状，并且当火焰被涡旋向上推动时，火焰保持该形状。由于颗粒聚集并附着在管壁上，因此在管壁附近没有火焰。喷嘴周围形成漩涡，颗粒浓度低，火焰蔓延缓慢。在爆炸过程中，颗粒在火焰之前从管中飞出。排出的火焰由于与涡旋的相互作用而呈现“蘑菇云”的形状，并且当火焰被涡旋向上推动时，火焰保持该形状。