Research On The Influence Of Geometric Boundary And Electric Field On Capillary Imbibition

The phenomenon of capillary imbibition is widespread in the natural world and industrial fields.After recent years of research,imbibition mechanics has been widely used in petroleum exploration,disease detection,light imaging and 3D printing.This paper aims to study the influence of geometric boundary and electric field on capillary imbibition,and to study the oscillation characteristics of capillary imbibition with a certain geometry,and to control the height and velocity of imbibition by adjusting the applied field parameters.First,the theoretical ascent formula of capillary imbibition flow from one to three dimensions is analyzed to derive and verify the relationship between ascent height and time.Establish the equilibrium equation in the actual imbibition situation,dimensionless the equilibrium equation based on the inertial term,and solve the theoretical value of the ordinary differential equation system to obtain that the imbibition height oscillates periodically with time and the wetting angle also does with time Periodic oscillation.The experimental phenomena were observed through quartz glass tubes and PDMS.In the horizontal imbibition,the liquid surface oscillation phenomenon can be observed at the edge of the capillary and at the variable cross section of PDMS,which confirms the correctness of the theoretical model.Secondly,using the phase field method and the dynamic grid method(ALE)to numerically simulate the imbibition flow under different geometric parameters,it can be obtained under the same parameter conditions,by comparing the liquid surface form conversion process,ascending height curve,pressure distribution curve and velocity The distribution curve and the prediction result of the theoretical model are consistent with the results of the phase field method and the moving grid method.Sample analysis is performed on the height curve of the imbibition simulation,the geometric parameters in the theoretical model are combined to predict the characteristic period,and finally the relationship between the characteristic period and the geometric parameter combination is obtained.Finally,the capillary imbibition under the electric field is studied.The electrowetting(EWOD)phenomenon on the medium is used to analyze the change of the three-phase contact angle,and the equilibrium equation of the imbibition under the electric field is established.In COSMOL,the imbibition movement under the electric field was simulated,and the imbibition height curve and velocity curve were analyzed.The results were consistent with the theoretical model.In theory,the electric field parameters were adjusted to control the imbibition behavior.