Many patterns of small particles flow are observed in nature.Pollen dust drugged by wind is a serious problem for human because this is the cause of hay fever.Some insects spray liquid particles to protect themselves against their enemy.It is important to understand the physics of particles flows in order to solve the problem or take these physics in the industrial application.Since it is difficult to observe or measure the solidgas two phase flow in detail,the numerical simulation is needed to understand its physical phenomena.Mass,momentum and heat transfer between particles and gas phase flow have to be solved simultaneously in order to understand the physics of particles flow.