论文部分内容阅读
利用基于格子玻尔兹曼方法的离散颗粒模型对单孔射流鼓泡床进行了研究.此算法基于四向耦合的离散颗粒模型,流体的控制方程采用考虑了孔隙率和流固相的滑移速度对流体流动影响的修正格子玻尔兹曼方法来求解,颗粒间相互作用通过时驱硬球模型求解,流固耦合采用EMMS曳力模型.首先研究了不同颗粒对形成气泡大小的影响,结果表明,在相同的射流气速下,粒径越大形成的气泡越小.在粒径相同的情况下,提高气体的入射速度,则形成的气泡越大.同时考察了气泡的分离时间与粒径以及射流气速的关系,结果表明,随着粒径以及射流气速在一定范围内的改变,气泡的分离时间并没有明显改变.另外颗粒床层扩展影响气泡形状,颗粒床层变宽后,气泡的形状接近于圆形;颗粒床层高度增加时,气泡明显变小.最后考察了气泡诱导现象,模拟发现当区域有空腔时,气泡会被诱导到空腔的方向.
A single-hole bubbling bubbling bed is studied by using a discrete particle model based on the lattice Boltzmann method, which is based on a four-way coupled discrete particle model. The governing equations of the fluid are based on porosity and fluid-solid slip Velocity on the flow of the fluid by the modified lattice Boltzmann method to solve the interaction between the particles by the time-driven hard-ball model, fluid-structure interaction using the EMMS drag model.First, the effect of different particles on the formation of bubble size, the results show , At the same jet velocity, the larger the particle size, the smaller the size of the bubble.When the particle size is the same, increasing the incident rate of the gas, the larger the size of the bubble.Furthermore, The results show that with the change of particle size and jet velocity in a certain range, the separation time of bubble does not change obviously.In addition, when the particle bed expands to affect the bubble shape and the particle bed becomes wider, The shape of the bubble is close to the circle; when the particle bed height increases, the bubble is obviously smaller.Finally, the bubble induced phenomenon is investigated, and the simulation shows that the bubble will be induced when there is a cavity in the region The direction of the cavity.