Frost Formation on Macro-Textured Surfaces with a Temperature Gradient

Frost formed on surfaces with temperature variations causes structural and energy efficiency problems in different sectors such as transportation, heat exchangers, and wind power industries. To understand and control the frost formation on three-dimensional surface structures with a temperature gradient, we tested surfaces with macro-textures such as arrays of cylindrical and conical pillar structures. These textured surfaces enable a trade-off condition between two gradients that induce (or inhibit) frost formation: thermal and chemical. When cooled from either side, a temperature and non-uniform water vapor flux distribution across the surface will result. The thermal and chemical gradients determine where the frost will first form, and how far the frost front will advance. Experimentally and numerically, we analyzed the location of the local critical point on the side wall of the macro-textures separating the frost covered and uncovered sections. The numerical calculations were then validated by experimental studies employing the structures. This research will further provide an essential set of surface design parameters for anti-frost surface design under forced convection conditions.