To study the processes of boiling on a smooth surface with contrast wettability, a hybrid model was developed based on Lattice Boltzmann method and heat transfer equation. The model makes it possible to describe the phenomena of natural convection, nucleate boiling, and transition to film boiling, and, thus, to study heat transfer and the development of crisis phenomena in a wide range of surface superheats and surface wetting characteristics. To find the optimal configuration of the biphilic surface, at the first stage a numerical simulation was carried out for a single lyophobic zone on a lyophilic surface. The dependences of the bubble departure frequency and the departure diameter of the bubble on the width of the lyophobic zone were obtained, and its optimal size was determined. At the next stage, the boiling process on an extended surface was studied in the presence of several lyophobic zones of a given size with different distances between them. It is shown that in the region of moderate surface superheat, the intensity of heat transfer on biphilic surfaces can be several times (more than 4) higher compared to surfaces with homogeneous wettability. Based on numerical calculations, an optimal configuration of the biphilic surface with the ratios of the lyophobic zones’ width of the order of 0.16 and the distance between the lyophobic zones in the range of 0.9–1.3 to the bubble departure diameter was found.

The hybrid Lattice Boltzmann method is adopted for a detailed study of surface wettability effects on evolution of vapor bubbles and temperature field of heat exchange surface at boiling. The simulation results show that the bubble departure diameter increases with an increase of static contact angle, and its value normalized by the capillary length approaches 3 for superlyophobic surface. In the range of contact angles of 110° – 129° the size of the dry area bounded by triple contact line greatly increases compared to the bubble departure diameter. At contact angles θ ⩾ 153° the dry area does not shrink even at the bubble departure stage and the typical film boiling regime is observed. It has been shown that the deterioration of wettability affects the evolution of the temperature field beneath the bubble, which leads to a significant change in the local heat transfer rate.

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