论文部分内容阅读
在构建开孔泡沫金属二维几何结构模型的基础上,采用格子Boltzmann方法基于孔隙尺度对泡沫金属内融化传热及流体流动过程进行了数值模拟,并重点分析了Rayleigh数、孔隙率及孔密度等对融化相变传热过程的影响.与纯相变材料融化具有光滑、清晰的相变界面、融化沿着热流方向整体推进的特征所不同的是,在泡沫金属结构下相变材料的融化以金属骨架为中心产生并推进展开,在融化前沿形成融化区和非融化区交错分布的特征,数值模拟结果与文献实验观测结果一致.此外,数值模拟表明相变材料的融化率随着Rayleigh数的增大、泡沫金属孔隙率的减少及其孔密度的增大而增大.“,”Based on a 2D theoretical model for metal foams,a lattice Boltzmann method is adopted to simulate the melting of phase change materials in metal foams at pore scale.The influence of Rayleigh number,porosity and pore density on phase change heat transfer is documented and discussed.The results show that the phase change materials close by metal matrix is first melted,suggesting a heat transfer mechanism dominated by conduction of metal matrix.The predicted results for the melting behavior of phase change materials in metal foams at the pore level agree reasonably with those obtained in the previous experimental studies,which are different from the melting processes of pure substance.The results also indicate that the melt volume fraction increases as the Rayleigh number and pore density increase,and the porosity decreases.