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Thermodiffusion or the Ludwig-Soret effect is known as the cross effect between the temperature gradient and induced separation of mixture species in multicomponent mixtures. The performance of the boundary driven non-equilibrium molecular dynamics enhanced heat exchange (eHEX) algorithm was validated by evaluating the sign and magnitude of the thermodiffusion process in methane/n-butane/n-dodecane (nC1–nC4–nC12) ternary mixtures. The eHEX algorithm consists of an extended version of the HEX algorithm with an improved energy conservation property. In addition to this, the transferable potentials for phase equilibria-united atom augmented force field was employed in all molecular dynamics (MD) simulations to accurately represent molecular interactions in the fluid. Our newly employed MD algorithm was capable to appropriately reflect the thermophobicity concept and the coupled effect of relative density and mole fraction of the mixture species on the thermodiffusion process. The separation ratio of the ternary mixture for five different compositions (at 333.15 K and 35 MPa) showed good agreement with experimental data and better accuracy in predicting the sign change of the intermediate component (nC4) as its concentration in the mixture increases, when compared to other MD models. [ABSTRACT FROM AUTHOR]

Summary Due to the growing needs of super coolant for industrial applications, in this article, we investigate experimentally as well as numerically the possible best heat transfer fluid. In this respect, we considered three nanofluids mixtures of Al2O3/water (concentrations of 0.2%vol and 0.3%vol) and 0.2%vol Fe3O4/water and 0.2%vol ND‐Fe3O4/water, and a hybrid fluid of 0.3%vol MWCNT‐Fe3O4 in water. First, we experiment with forced convection in three porous channels using two concentrations of 0.2 and 0.3%vol of Al2O3 nanofluid, respectively. We validated the experimental results with the numerically simulated data and confirmed satisfactory agreement among them. Second, using the numerical code, we predicted the performance of 0.2%vol Fe3O4 nanofluid, 0.2%vol (ND‐Fe3O4) nanofluid, and a hybrid fluid of 0.3%vol (MWCNT(26%)‐Fe3O4(74%)) for heat extraction. With such configuration, the usefulness of using the proposed nanofluid and hybrid fluid enlarge the knowledge for heat enhancement. Our experimental results show that 0.2%vol Al2O3 efficiently transfers heat compared to the 0.3%vol Al2O3. The simulated results show that 0.2%vol Fe3O4 nanofluid is the best fluid for heat extraction among the experimentally and numerically studied fluids. [ABSTRACT FROM AUTHOR]