Yang Huizhu, Li Yongyao, Ma Binjian, Zhu Yonggang
Center for Microflows and Nanoflows, School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen 518055, China.
Materials (Basel). 2021 Jun 8;14(12):3153. doi: 10.3390/ma14123153.
Due to their high porosity, high stiffness, light weight, large surface area-to-volume ratio, and excellent thermal properties, open-cell metal foams have been applied in a wide range of sectors and industries, including the energy, transportation, aviation, biomedical, and defense industries. Understanding the flow characteristics and pressure drop of the fluid flow in open-cell metal foams is critical for applying such materials in these scenarios. However, the state-of-the-art pressure drop correlations for open-cell foams show large deviations from experimental data. In this paper, the fundamental governing equations of fluid flow through open-cell metal foams and the determination of different foam geometry structures are first presented. A variety of published models for predicting the pressure drop through open-cell metal foams are then summarized and validated against experimental data. Finally, two empirical correlations of permeability are developed and recommended based on the model of Calmidi. Moreover, Calmidi's model is proposed to calculate the Forchheimer coefficient. These three equations together allow calculating the pressure drop through open-cell metal foam as a function of porosity and pore diameter (or strut diameter) in a wide range of porosities = 85.7-97.8% and pore densities of 10-100 PPI. The findings of this study greatly advance our understanding of the flow characteristics through open-cell metal foam and provide important guidance for the design of open-cell metal foam materials for different engineering applications.
由于具有高孔隙率、高刚度、轻质、大的表面积与体积比以及优异的热性能，开孔金属泡沫已被应用于广泛的领域和行业，包括能源、交通、航空、生物医学和国防工业。了解开孔金属泡沫中流体流动的特性和压降对于在这些场景中应用此类材料至关重要。然而，目前最先进的开孔泡沫压降关联式与实验数据存在较大偏差。本文首先给出了流体流经开孔金属泡沫的基本控制方程以及不同泡沫几何结构的确定方法。然后总结了各种已发表的预测开孔金属泡沫压降的模型，并与实验数据进行了验证。最后，基于卡尔米迪模型开发并推荐了两个渗透率的经验关联式。此外，还提出了卡尔米迪模型来计算福希海默系数。这三个方程共同使得能够在孔隙率范围为85.7 - 97.8%和孔隙密度为10 - 100 PPI的情况下，计算通过开孔金属泡沫的压降作为孔隙率和孔径（或支柱直径）的函数。本研究的结果极大地推进了我们对通过开孔金属泡沫流动特性的理解，并为不同工程应用的开孔金属泡沫材料设计提供了重要指导。
