Turbulent heat transfer of viscoelastic fluid flow accompanied by drag reduction with DNS analysis

It is well known that turbulent drag can be reduced effectively by adding a small amount of water-soluble polymer or surfactant to a liquid flow at high Reynolds number. However, the heat transfer of drag-reducing flow is deteriorated, thought to be approximately in accordance with the drag reduction because of the similarity of momentum and heat transfer. In this study, turbulent heat transfer of drag-reducing in a channel flow with DNS was carried out to investigate the dissimilarity behaviour between heat transfer and friction of a viscoelastic drag-reducing flow by surfactant additives. The effect of rheological parameters was carefully investigated to find the conditions at which the dissimilarity between heat and mass appears.