A homogenization approach for buoyancy-induced flows over micro-textured vertical surfaces

Wetting of rough surfaces: a homogenization approach

The contact angle of a drop in equilibrium on a solid is strongly affected by the roughness of the surface on which it rests. We study the roughness-induced enhancement of the hydrophobic or hydrophilic properties of a solid surface through homogenization theory. By relying on a variational formulation of the problem, we show that the macroscopic contact angle is associated with the solution of...

Magnetohydrodynamic Free Convection Flows with Thermal Memory over a Moving Vertical Plate in Porous Medium

The unsteady hydro-magnetic free convection flow with heat transfer of a linearly viscous, incompressible, electrically conducting fluid near a moving vertical plate with the constant heat is investigated. The flow domain is the porous half-space and a magnetic field of a variable direction is applied. The Caputo time-fractional derivative is employed in order to introduce a thermal flux consti...

Holographic microscopy and microfluidics platform for measuring wall stress and 3D flow over surfaces textured by micro-pillars

Understanding how fluid flow interacts with micro-textured surfaces is crucial for a broad range of key biological processes and engineering applications including particle dispersion, pathogenic infections, and drag manipulation by surface topology. We use high-speed digital holographic microscopy (DHM) in combination with a correlation based de-noising algorithm to overcome the optical interf...

Modelling Buoyancy Induced Flows of Passive Cooling Systems

The main objective of this study is to develop and validate a systematic methodology to model a system of buried pipes, assisted by a solar chimney to promote the natural ventilation, in the whole building simulation software ESP-r (Clarke 2001), from a software user perspective. This development was supported by monitored data collected at an experimental site in Évora, Portugal. A multi-zone ...

Simulating Flows Over Wavy Inclined Surfaces