Modelling of pressure-driven liquid flows in conjugate rectangular microchannel with electric double layer effects

This work deals with code development using a finite volume scheme for the liquid flow and heat transfer in microchannels, with streaming potential as the driving force. The concept of the electric double layer (EDL) was introduced to explain the microscale deviation. Governing equations were derived for fully developed rectangular microchannels´ pressure-driven flows. For realistic modeling of the problems, a conjugate analysis, that solves both the solid and liquid regions, was conducted. An additional source term resulting from the EDL effects was introduced in the conventional momentum equation, thereby modifying the flow and heat transfer characteristics. Analysis concerning the effects of ionic concentration, zeta potential and channel dimensions were included. The computed results reveal significant deviations in the velocity and temperature profiles under EDL effects. Predicted friction factors and Nusselt numbers were compared for both EDL and nonEDL considerations. Stronger deviations were observed as the aspect ratio decreases, indicating the role of EDL effects in microscale liquid flow