Treelike Thermal Structures on the Water Surface. Surface Film Modeling

The hypothesis that the previously discovered treelike thermal structures on the water surface (Phys. Fluids 34, 053112 (2022), cited below as [1]) can be explained by the presence of a surface-active impurity film is being investigated. It is shown that the simplest mathematical model of the film based on the free slip condition on the water surface, allows one to obtain previously observed structures. At the same time, the no-slip boundary condition leads to results that are inconsistent with experiment. In addition to the film, the presence of convective structures due to the horizontal and vertical temperature gradients in the water layer with an aspect ratio of about 5 is important for the appearance of treelike structures on the surface.