摘要
基于随机四参数生长法构造不同孔隙度的多孔介质,采用稀疏矩阵存储方式存储内部流体节点、流固边界节点及物理边界节点。通过顶盖驱动流和方腔自然对流验证了格子Boltzmann方法处理多孔介质的传热问题的可行性。基于格子Boltzmann耦合传热模型,计算得到复杂多孔介质内的速度及温度分布云图,对多孔介质内的速度、温度与迭代时间及孔隙度的关系作了详细的分析。结果表明:多孔介质中速度和温度分布受孔隙度影响,相同压力梯度下,平均速度随着孔隙度的增加而增大;孔隙度相同时,平均速度随着压力梯度的增加而增大。相同温差条件下,随着孔隙度的增大,多孔介质中对流传热达到稳态的时间逐渐减小;多孔介质内最大温度出现在高温壁面处,靠近高温壁面的孔隙度越大,高温部分体积越大。相同条件下,孔隙度越小,多孔介质的平均温度越低。
A porous medium with different porosity is modelled based on the random four parameters growth method and the Sparse Matrix Storage Formats is used to store the internal fluid node, the fluid solid boundary node and the physical boundary node. The simulation of lid driven flow and natural convection in a square cavity are studied and the correctness of the Lattice Boltzmann model is verified. Based on the lattice Boltzmann method, the velocity and temperature field distribution in the complex porous medium are calculated, and the relationship between velocity or temperature and each of iteration time and porosity are analyzed in detail respectively. The results show that the distributions of fluid velocity and temperature are affected by the porosity of the porous medium. With an increase of porosity, the average velocity increases under the same pressure gradient; with an increase of pressure gradient, the average velocity increases under the same porosity. At the same temperature, with the increase of porosity, the time convection heat transfer reaches a steady-state in the porous medium is gradually reduced. The maximum temperature appears at the high temperature surface, and the bigger the porosity near the high temperature wall, the greater the volume of the high temperature part. With a decrease of porosity, the average temperature of the porous medium decreases under the same condition.
出处
《石油科学通报》
2017年第1期76-85,共10页
Petroleum Science Bulletin
