摘要
将离散单元法和计算流体力学相结合,在自行编制程序的基础上对流化床内气固两相流中颗粒的旋转特性进行数值模拟,得到了气体的速度场、颗粒的速度场、颗粒平均体积分数以及颗粒平均转速分布,并重点分析了颗粒的旋转对颗粒平均速度、床层膨胀高度和平均空隙率的影响以及影响颗粒平均转速的因素.结果表明:颗粒的旋转不仅会对颗粒自身的运动产生影响,也会对其所在的流场产生一定影响;颗粒平均转速不仅与颗粒间的碰撞次数有关,还与颗粒间的碰撞强度有关,且密度大的颗粒的平均转速小于密度小的颗粒,直径小的颗粒的平均转速大于直径大的颗粒.
Rotating characteristics of particles in fluidized bed were numerically simulated with self-devel oped program using discrete element method and computational fluid dynamics, so as to obtain the gas ve locity field, particle velocity field and the distribution of particle average volume fraction and particle aver age rotating speed, and to analyze the effect of particle rotation on the particle average velocity, bed expan sion height, average void fraction, and the factors influencing the particle rotating speed. Simulation re sults show that the particle rotation not only influences the particle movement, but also has some impacts on the flow field. The average rotating speed of particles has relationship with not only the collision fre quency but also the collision strength, and the average rotating speed of high-density particles is less than that of the low-density particles, while the average rotating speed of small-sized particles is higher than that of the large-sized particles.
出处
《动力工程学报》
CAS
CSCD
北大核心
2014年第3期189-195,共7页
Journal of Chinese Society of Power Engineering
关键词
流化床
气固两相流
离散单元法
颗粒旋转
数值模拟
fluidized bed
gas-solid two-phase flow
discrete element method
particle rotation
numericalsimulation