摘要
在Lennard-Jones流体自扩散系数方程的基础上，结合链状硬球流体自扩散系数的分子模拟数据，提出了链状Lennard-Jones流体的自扩散系数方程。将所提出的方程应用于计算长链烷烃和硅油在0.1~600MPa下的自扩散系数，其平均相对偏差在10%以内，计算结果优于自扩散系数的粗糙Lennard-Jones模型。
The self-diffusion coefficients are required in many engineering calculations involving mass transfer. In this work, an expression for the self-diffusion coefficient of a Lennard-Jones chain fluid is proposed by combining the self-diffusion coefficient equation for a Lennard-Jones fluid with the molecular dynamics simulation data for a hard-sphere chain fluid. The real long chain molecules such as alkanes and silicone oils are modeled as chains of freely tangent Lennard-Jones segments. The obtained equation has been applied to the calculations of the self-diffusion coefficients for the long chain alkanes and the liquid silicone oils in the pressure range from 0.1 MPa to 600 MPa. The average absolute deviations for these systems are within 10%. The calculated results are superior to that of the rough Lennard-Jones model. These results show that the Lennard-Jones chain model given in this work can be successfully used to calculate the self-diffusion coefficients for long chain molecules over wide ranges of temperature and pressure.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2001年第1期1-5,共5页
Journal of Chemical Engineering of Chinese Universities
基金
化学工程联合国家重点实验室资助开放课题
