The effect of rearrangement of the vortex structure on heat transfer under conditions of increasing depth of a spherical dimple on the wall of a narrow channel

The results of numerical simulation of convective heat transfer in a spherical dimple located on the wall of a narrow square channel are used to analyze the effect of the hole depth on the vortex dynamics and intensification of heat transfer. It is demonstrated that the rearrangement of the separation flow structure from symmetric to monotornado is accompanied by a significant intensification of heat transfer both in the region of the spherical dimple ($\sim60\%$) and in the wake behind it ($\sim45\%$).