【摘要】 为了满足工程上对液体导热率的要求,在方阱模型基础上提出了计算液体导热率的方程。所得的导热率计算方程包括分子平动贡献项和分子内部能量贡献项。为了计算方便,根据分子模拟数据提出了计算中所需的方阱流体的径向分布函数的关联式。物质的能量参数由其临界温度估算,而硬壳体积则由基团贡献法获得。考虑到实际液体有别于方阱流体,在实际液体导热率计算中引入了一个与密度有关的校正参数。使用该文提出的方法,对液体氩及10种液态烃类物质的导热率进行了计算,其计算的平均相对误差小于5.3%。更多还原

【Abstract】 The squarewell model was used to develop an engineering equation for the thermal conductivities of liquids. The equation includes a translational part and an internal part. The equation was simplified by expressions for the radial distribution functions of the squarewell fluid calculated using molecular dynamics simulations. The energy parameter for each substance is estimated from its critical temperature and the hardcore volume is obtained using a group contribution method. To calculate thermal conductivities of real liquids, a density dependent correction parameter was introduced to represent the difference between the real liquid and the squarewell liquid. The thermal conductivities of liquid argon and ten hydrocarbons are calculated using the proposed equation with average relative deviations smaller than 5.3%.更多还原