温度和分子间作用对切向动量协调系数的耦合效应

THE COUPLING EFFECT OF TEMPERATURE AND INTERMOLECULAR INTERACTION ON TMAC

切向动量协调系数(TMAC)是描述气体滑移流动的重要边界条件。运用非平衡分子动力学方法,构建了能够反映流体粒子与壁面粒子相互作用关系的物理模型。结果显示:当壁面存在吸附层或壁面无气体吸附层时,同一势能强度下TMAC值都随着温度的升高而降低;而在吸附层能够解吸附的温度,TMAC值发生突跃。在本文的模拟条件下,气体粒子离开壁面吸附的能力和壁面粒子及吸附层粒子热运动产生的粗糙度决定了TMAC值的分布。

The tangential momentum accommodation coefficient（TMAC） is the importance boundary conditions for describing gas slip flow.A physical model was constructed using non-equilibrium molecular dynamics method,which reflects more realistic particle interaction between fluid and solid wall.The results show TMAC values decrease with increasing temperature under the same potential energy intensity when there is gas adsorption layer or not one on the wall and TMAC values occur to jump when the temperature arrived desorption temperature of the adsorption layer.Under the simulated conditions of this paper,the distribution of TMAC was determined by the capacity of gas particles leaving the wall desorption capacity and the roughness generated by thermal motion of the wall and adsorption layer particles.