Microscale transport phenomena

Free-flow and porous media coupling

We investigate momentum transport and boundary-layer development at the interface between free-flow regions and porous materials using high-resolution microfluidic experiments. Our work combines Hele–Shaw micromodels, micro-PIV velocimetry, and analytical Darcy–Brinkman modeling to reveal how permeability, porosity, and interfacial geometry govern slip velocity, channeling, and transport across scales. These studies provide experimentally validated frameworks for coupled free-flow/porous-media systems relevant to microfluidics, energy systems, transpiration cooling, filtration, and transport in engineered porous structures. Recent results demonstrated permeability-dependent boundary-layer formation, experimentally validated viscosity-invariant slip length behavior, and exact analytical solutions for laminar flow near permeable interfaces.

References
Del Mastro, M. and Terzis, A. On the exact solutions of Darcy–Brinkman model in rectangular Hele–Shaw channels under no-slip and slip boundary conditions. Phys. Fluids 37, 032005 (2025).
Del Mastro, M., Kabour, R. and Terzis, A. Experimental validation of viscosity-invariant slip length at fluid–porous interfaces using water and oleic acid. Phys. Fluids 37, 082140 (2025).
Del Mastro, M. and Terzis, A. An experimental investigation of boundary layer over permeable interfaces in Hele-Shaw micromodels. Phys. Fluids 36, 112110 (2024).