Experimental Study On Interfacial Characteristics Of Stratified Oil-water Two-phase Flow In Horizontal Pipe

prediction of oil-water interface with a high accuracy.3.New types of pipe cross-section geometrical relationship and interfacial shear stress closure relation are established according to the interface curvature and fluctuation characteristics in stratified oil-water two-phase flow.Thereby,a new pressure drop prediction model of stratified oil-water two-phase flow is established by modifying the one-dimensional two-fluid model.The results show that,through the prediction of oil-water interface curvature based dynamic contact angle,the proposed model can effectively improve the prediction accuracy of pressure drop in stratified oilwater flows.4.Flow structure of stratified oil-water flows are detailly detected based on the measurement of laser-induced fluorescence.The hydrodynamic mechanisms of the oilwater interface instability and droplet detachment are analyzed.The stability boundary is predicted by the Kelvin-Helmholtz stability analysis which is combined with the modified geometric closure relation of oil-water interface based on the dynamic contact angle.It is found that the modified Kelvin-Helmholtz model can preferably predict transitional boundary from stratified flow to non-stratified flow.