论文标题
数值预测对使用焓 - 孔隙率法的熔化和凝固模拟中渗透系数的敏感性
Sensitivity of Numerical Predictions to the Permeability Coefficient in Simulations of Melting and Solidification Using the Enthalpy-Porosity Method
论文作者
论文摘要
关于渗透率系数的价值（也称为糊状区域常数）的高度不确定性和冲突的文献数据，该数据旨在抑制糊状区域中的流体速度并在固体区域中抑制它们，这是使用固定网状孔隙率技术在固体区域中的关键缺点，用于建模非相位层次的固定式孔。在本研究中，仔细检查了数值预测对该系数值的敏感性。使用等温和非等热熔体和固化问题的基于有限体积的数值模拟，确定了提高灵敏度的原因。已经发现，根据糊状区域的厚度和速度场，固液界面形态和相变速率对渗透系数敏感。证明等温相变问题的数值预测与足够细网格的渗透系数无关。还表明，可以通过适当定义的péclet数来评估对渗透系数选择的敏感性。
The high degree of uncertainty and conflicting literature data on the value of the permeability coefficient (also known as the mushy zone constant), which aims to dampen fluid velocities in the mushy zone and suppress them in solid regions, is a critical drawback when using the fixed-grid enthalpy-porosity technique for modelling non-isothermal phase-change processes. In the present study, the sensitivity of numerical predictions to the value of this coefficient was scrutinised. Using finite-volume based numerical simulations of isothermal and non-isothermal melting and solidification problems, the causes of increased sensitivity were identified. It was found that depending on the mushy-zone thickness and the velocity field, the solid-liquid interface morphology and the rate of phase-change are sensitive to the permeability coefficient. It is demonstrated that numerical predictions of an isothermal phase-change problem are independent of the permeability coefficient for sufficiently fine meshes. It is also shown that sensitivity to the choice of permeability coefficient can be assessed by means of an appropriately defined Péclet number.
