OICC Press Journal of Theoretical and Applied Physics 2251-7235 17 1 2023 11 17 Numerical investigation of the fullerene and doped fullerene effects on thermal performance of water base-fluid 10.57647/j.jtap.2023.1701.13 EN Hamid Vanaie Science Department, Bushehr Branch, Islamic Azad University, Bushehr, Iran 0000-0002-4624-5447 Mojtaba Yaghobi Department of Physics, Ayatollah Amoli Branch, Islamic Azad University, Amol 46351-43358, Iran. Ebrahim Hydari Science Department, Bushehr Branch, Islamic Azad University, Bushehr, Iran. Ahmad Saadi Science Department, Bushehr Branch, Islamic Azad University, Bushehr, Iran Journal Article 2023 11 17 In this study, the fullerenes have inserted into water base-fluid to investigate the atomic and thermal behavior of nanofluid and hybridnanofluid as heat transfer fluid. This choice derives from low cast and high thermal stability of this nanostructure. Our computational results from Molecular Dynamics (MD) simulations indicate that the addition of nanoparticles with 4% atomic ratio produced an appreciable effect on the nanofluid. The maximum value of density, velocity, and temperature profile have reached to 0.029 atom/Å3, 0.005 Å/ps, and 321 ̊C. Its thermal conductivity would increase to 0.82 W/m.K. Heat flux reache to 2019 KW/m2 after t=10 ns. Also, the aggregation phenomenon detected after t= 5.84 ns. This hybridnanofluid has used to enhance the energy efficiency of the heat exchangers at high temperature for the nuclear industry applications for the first time. Numericaly, by the temperature increase of nanofluid structure to 625.15 K, thermal power of nanofluid reache to 3881 MW. The thermal Performance of hybridnanofluid can be improved by more than 30% by adding concentration of fullerene and doped fullerene at 4 vol%.