A molecular dynamics study of a nanoscale liquid bridge under shear

The lubrication phenomenon occurring by shearing a nanoscale liquid bridge was simulated using the molecular dynamics method by varying the width of the liquid bridge, and the momentum transport phenomena of the liquid bridge were analyzed. The Fennell method was used to calculate the coulombic interaction and the Lees–Edwards method was used to maintain the velocity gradient in the liquid bridge. First, to estimate the overall viscosity coefficient of the liquid bridge, the width and interfacial region of the liquid bridge were determined. The overall viscosity coefficient was then modeled by considering two contributions from the bulk and interfacial region and the momentum fluxes or viscosity coefficients in the bulk and interfacial region were obtained. The model approximately expresses the simulation results, and the viscosity of the interfacial region was determined to be between one fourth and one third of that of the bulk. In addition, the partial momentum fluxes were calculated to verify the validity of the proposed model.