Investigations of interfacial heat transfer and phase change on bioinspired superhydrophobic surface for anti-icing/de-icing

The bioinspired superhydrophobic surface (SHS) demonstrates the capability in terms of anti-icing/de-icing, however, the mechanisms of micro-/nanostructure on interfacial heat transfer and phase change are inadequately revealed during freezing. A comprehensive solution method, considers a modified roughness, texture, and thermal properties of SHSs material, is developed in this study. This method, coupled Level Set-Volume of Fluid (CLSVOF) with solidification model and combined freezing experiments, captures the ice-liquid-gas interface change and anisotropic interfacial heat exchange. Numerical and experimental results in frozen nucleation illustrate that the micro-/nanostructure blocks heterogeneous heat transfer via the stored air, extended the freezing time and the freezing delay rate is 194%. Accordingly, the numerical model between freezing time (t) and surface temperature (T-surface), is following power function t = 959.42 x (273.15-T-surface)(-0.777). Moreover, the moving droplets overcome the freezing adhesion through shortening the contact time then to limit the heat exchange process, allowing their self-removal before freezing. The de-icing analysis confirms that the larger contact angle (CA) and cavitation structure jointly affect the solid-liquid contact area, and the bionic surface in this study reduces the adhesion strength of frozen droplets by 4 times.