Comparison of atomic simulation methods for computing thermal conductivity of n-decane at sub/supercritical pressure

n-Decane is the most commonly used component in surrogate to study the properties of RP-3 aviation kerosene for regenerative cooling systems and the engine injection systems. In this paper, the equilibrium molecular dynamics (EMD) and the reverse non-equilibrium MD (RNEMD) methods are adopted and compared in the prediction of the thermal conductivity of the sub/supercritical n-decane. Four different united atom (UA) force field models and four all-atomic force field models are compared in the EMD simulations. It is found that the UA models predict much better than the all-atom force field models and EMD methods show better prediction accuracy than the RNEMD methods with the same UA models. The SKS model has the best prediction accuracy among all the force field models for EMD and RNEMD simulations. The MD results are compared with experimental data of RP-3 aviation kerosene; it is obtained that the overall averaged absolute relative deviation (AARD) of EMD simulations with the SKS force field model for the single component substitute of aviation kerosene by n-decane is 2.05%. Moreover, the radial distribution functions are calculated via MD simulations to make a better understanding of the temperature dependences of the thermal conductivity at sub/supercritical pressure of n-decane at a molecular level. The findings of this work could provide important guidance for the investigation of thermal conductivity of n-alkanes and n-alkane-based fuels.