【摘要】 本文把多脉冲激光全息术应用于实际的工业煤粉燃烧器的气-固两相流场的研究中,获得到如下重要结论:(1)在高剪切流区,Saffman力与粘性阻力相比,具有相同量级或高一个量级。(2)当颗粒与壁面相碰时,由于壁面的摩擦力,造成颗粒高速旋转(可达1800n/s)。之后,在气体粘性反力矩作用下,其转速随时间呈指数函数急剧下降。(3)当颗粒与壁面相碰之后的短时间内,Magnus力必须考虑,其后可以忽略。根据实验结果整理出颗粒碰壁关系式来表示在颗粒碰壁附近Saffman力和Magnus力的综合作用。更多还原

【Abstract】 In this paper the application of multi-pulse laser holography to observe the particle fields in a practical industrial pulverized-coal burner is introduced. From the observations the following important conclusions are obtained: (1) In a high shear flow the Saffman force is in the same order of magnitude as the viscous drag or an order larger than it. (2) When a particle comes into collision with a wall surface, fast rotation (up to 1800 cycles/sec) of the particle is induced by the friction on the wall surface. Then by action of the viscous an-titorque the rotating velocity drops rapidly down as an exponential function of time. (3) In a short duration after collision, the effect of the Magnus force should be considered, while it can be then neglected. On the basis of the experimental results, the effects of both Saffman force and Magnus force can be expressed by the Law of Collision of particles.更多还原