Pore-scale study on the stress jump coefficient in porous composite system

The stress jump coefficient at the fluid/porous interface is a fundamental parameter to study the velocity distribution in a porous composite system. In this paper, a substantial work is carried out to investigate the characteristics of the stress jump coefficient. To this end, the real pore structure of metal foam is constructed using the Weaire-Phelan model, and the macro model and the pore-scale model are presented to simulate a complex three-dimensional porous composite system. Furthermore, a novel method to determine the stress jump coefficient is proposed. The influences of the inlet velocity, the rotation number, the porosity, the free fluid layer thickness, and the flow pattern (the Poiseuille flow, the free boundary flow, and the rotating channel flow) on the stress jump coefficient are studied. The results show that the stress jump coefficient varies with the porosity, which shows that it is dependent on the porous structure. It also found that the stress jump coefficient is independent of the inlet velocity, the rotation number, and the flow pattern. When the thickness of the free fluid layer is large, the stress jump coefficient is also independent of the thickness of the fluid layer.