Interfacial dynamics of immiscible binary fluids through ordered porous media: The interplay of thermal and electric fields

We report the interplay of electrical and thermal fields on the interfacial dynamics of two immiscible fluids inside a periodic porous domain. The alternating current electrothermal mechanism is employed to generate the two phase flow. The surfaces of the porous blocks are wetted with wettability conditions which are manifested by a predefined static contact angle. Depending on the surface affinity and the electrical parameters, two distinctive spatio-temporal regimes can be identified, namely, trapping of the displaced fluid between the two consecutive porous blocks (formation of liquid bridge) and merging of contact lines after traveling the obstacle (complete interface recovery). Results show that liquid bridge formation and complete interface recovery are strongly influenced by the viscosity and thermal conductivity contrasts, in addition to the relevant electro-thermal parameters.