摘要: 为了深入研究撞击流过程中，颗粒包覆工艺传递过程的强化机理，建立了气–固两相撞击流中颗粒在流场中的运动模型，对颗粒在流场中的停留时间、渗入距离等参数进行了模拟计算。选取单喷嘴喷射单一颗粒、单喷嘴喷射颗粒群以及双喷嘴喷射颗粒群三种流动情况，在不同的膨胀前压力、膨胀前温度和喷嘴出口间距等操作工艺参数条件下，得出了颗粒在气–固两相撞击流中的停留时间与渗入距离的变化规律。此外，利用粒子图像测速技术测试了流体喷射过程中颗粒运动情况，对气–固两相撞击流场中的速度分布进行了定量描述。
Abstract:
This work
establishes the motion model for the particles in the gas-solid impact flow, to
study the strengthening mechanism of the flow transfer in the impinging fluid.
The particles’ residence time and particles
through length are simulated. Three conditions including the condition of
single particle from single nozzle (SP), particles group from single
nozzle (SPG) and particles group from double nozzles (DPG) are chosen in this
study. Also, the pressure and the temperature before expansion as well as the
distance between two opposite nozzles exits are defined as the different initial
conditions. The changing tendencies for the particles’ residence time and
particle through length of the particle are obtained. In addition, the Particle
Image Velocimetry is used to describe the characteristic of the supercritical
gas-solid impact flow.