On the links between unsteady separation and Nusselt number deterioration during vortex-wall interaction

A CFD study of an axisymmetric vortex ring interacting with a flat, constant-temperature, heated wall is conducted to the physical nature mechanisms leading deterioration in heat transfer due unsteady boundary layer separation resulting from vortex-wall interaction. The utilizes supplemental computation hypothetical flow configuration which slip allowed at eliminate during Comparison between and cases enables “isolation”, hence understanding role Nusselt number (Nu). It found that near-wall upwash velocity Nu fundamentally altered by presence spearation. Without separation, driven directly primary ring. In contrast, modified significantly blockage interaction secondary modification associated development “sublayer” responsible for independent behavior overall thermal thickness.