摘要
基于格子玻尔兹曼方法,利用四参数随机生长法生成梯度多孔介质,采用描述相变糊状区的两区域模型,求解了孔隙尺度下梯度多孔介质腔体内固液相变过程,分析了相变材料的相场分布、融化速率及热壁面平均努塞尔特数的变化,并改变相邻多孔介质孔隙率的差值,探究了梯度多孔介质对固液相变影响的一般性规律。结果表明:相变材料的融化过程与多孔介质梯度的方向有关,沿热量传递方向梯度(x向梯度)变化对相变材料融化速率影响大,且低孔隙率多孔介质靠近高温壁面时相变材料融化速率最快;竖直方向梯度(z向梯度)变化对相变材料融化速率影响小,融化速率的不同主要体现在相变后期方腔内竖直方向温度均匀性的差异;相邻孔隙率差值的改变影响方向梯度多孔介质的传热能力。
Based on the Lattice Boltzmann Method,this paper uses the Quartet Structure Generation Set(QSGS)to generate gradient porous media,and uses the two-region model describing the phase change mushy zone to solve the solid-liquid phase change process in the gradient porous media cavity at pore scale.The phase field distribution,melting rate and Nu_(ave)of the heated wall were analyzed.By changing the difference of porosity of adjacent porous media,the general law of the effect of gradient porous media on solid-liquid phase change was investigated.The results show that the melting process of Phase Change Material(PCM)is related to the direction of the gradient porous media,and the change of the gradient along the heat transfer direction(x direction gradient)has a great influence on the melting rate of PCM,and the melting rate of PCM is the fastest when the porous media with low porosity is close to the high temperature wall.The change of the vertical gradient(z direction gradient)has little effect on the melting rate of PCM.The difference of melting rate is reflected in the difference of the vertical temperature uniformity in square cavity in the later stage of phase change.The change of adjacent porosity difference affects the heat transfer performance of direction gradient porous media.
作者
崔云杰
陈宝明
云和明
随立言
CUI Yunjie;CHEN Baoming;YUN Heming;SUI Liyan(School of Thermal Engineering,Shandong Jianzhu University,Jinan 250101,China)
出处
《山东建筑大学学报》
2023年第5期65-73,81,共10页
Journal of Shandong Jianzhu University
基金
国家自然科学基金项目(51976111)。
关键词
格子玻尔兹曼方法
四参数随机生长法
固液相变
梯度多孔介质
Lattice Boltzmann Method
Quartet Structure Generation Set
solid-liquid phase change
gradient porous media
