温度对水的粘度和扩散系数影响的研究

采用分子动力学方法(MD)研究了水在不同温度下的内能、粘度、扩散系数及径向分布函数.研究结果表明,随着温度的升高,内能增加,粘度系数减小,扩散系数增大,且粘度系数和扩散系数符合Arrhenius行为.从径向分布函数的分析町知,温度升高,加剧了水分子的运动和碰撞,改变了水的微观结构,使内能增加,从而改变了水的粘度系数和扩散系数.

Temperature on the Viscosity and Diffusion Coefficient of Water

Molecular dynamics (MD) simulations are performed to simulate the internal energy,viscosity,diffusion coefficients and radial distribution functions of water at different temperatures.The results show that with increasing temperature,when the internal energy of water is increased that the viscosity coefficients are decreased and diffusion coefficients are increased.The viscosity coefficient and diffusion coefficient are accord with the Arrhenius behavior.From the radial distributions analysis,it is known that the motion of water molecules and collisions is aggravated by the temperature increasing,which changes the microstructure of water.So it makes internal energy increase and changes the viscosity coefficients and diffusion coefficients.