On the mechanism of convective heat transfer enhancement in a turbulent flow of nanofluid investigated by DNS and analyses of POD and FSP a b s t r a c tIn this study, direct numerical simulations (DNS) are performed for turbulent nanofluid flows in order toinvestigate the mechanism of convective heat transfer enhancement induced by the addition of nanoparticlesto the base fluid. In the energy equation of a turbulent nanofluid flow, a new thermal dispersionterm taking the thermal ...