The thermophysical properties of biodiesel surrogates are of great importance for the development of the new and clean fuel substitutes or additives. Experimental investigation and molecular dynamic simulation of the related thermophysical properties such as the liquid density, kinematic viscosity and surface tension over a sufficient wide temperature range will facilitate the corresponding researches of selecting the proper fuel surrogates and designing the spray system of the internal combustion engine. Therefore, the present study investigated liquid surface tension and kinematic viscosity of the proposed physical biodiesel surrogates of n-hexadecane with ethyl hexanoate and ethyl heptanoate by the surface light scattering method at three mole fractions (0.25, 0.50 and 0.75) over the temperature range from (353.15 to 433.15) K. Additionally, the liquid density was also determined by a U-tube densimeter in the temperature range between (293.15 and 433.15) K. Meanwhile, three force fields including OPLS-AA, GROMOS and AMBER were selected and validated with n-hexadecane and ethyl heptanoate in a wide temperature range and the GROMOS force field was demonstrated to be the best one for the description of the three thermophysical properties of the two fluids. A further molecular dynamic simulation with GROMOS force field was applied to the proposed binary surrogates of n-hexadecane with ethyl hexanoate and ethyl heptanoate, and the results for the three properties agreed well with their experimental values over the entire temperature range.

生物柴油替代物的热物理性质对开发新型清洁燃料替代品或添加剂至关重要。在足够宽的温度范围内进行相关热物理性质（如液体密度，运动粘度和表面张力）的实验研究和分子动力学模拟，将有助于选择合适的燃料替代物和设计内燃机喷雾系统的相应研究。因此，本研究通过表面光散射法研究了正十六烷与己酸乙酯和庚酸乙酯的拟议物理生物柴油替代物的液体表面张力和运动粘度，其温度范围为3摩尔分率（0.25、0.50和0.75）。 （353.15至433.15）K。此外，液体密度也由U形管密度计在（293.15和433.15）K之间的温度范围内确定。同时，选择了三个力场，包括OPLS-AA，GROMOS和AMBER，并用正十六烷和庚酸乙酯进行了验证。广泛的温度范围和GROMOS力场被证明是描述两种流体的三种热物理性质的最佳方法。利用GROMOS力场对分子进行了进一步的分子动力学模拟，对正十六烷与己酸乙酯和庚酸乙酯的二元替代物进行了模拟，这三个性质的结果与它们在整个温度范围内的实验值非常吻合。选择了三个力场，包括OPLS-AA，GROMOS和AMBER，并在很宽的温度范围内用正十六烷和庚酸乙酯进行了验证，事实证明，GROMOS力场是描述两者的三个热物理性质的最佳场强液体。利用GROMOS力场对分子进行了进一步的分子动力学模拟，对正十六烷与己酸乙酯和庚酸乙酯的二元替代物进行了模拟，这三个性质的结果与它们在整个温度范围内的实验值非常吻合。选择了三个力场，包括OPLS-AA，GROMOS和AMBER，并在很宽的温度范围内用正十六烷和庚酸乙酯进行了验证，事实证明，GROMOS力场是描述两者的三个热物理性质的最佳场强液体。利用GROMOS力场对分子进行了进一步的分子动力学模拟，对正十六烷与己酸乙酯和庚酸乙酯的二元替代物进行了模拟，这三个性质的结果与它们在整个温度范围内的实验值非常吻合。