Electroviscous effect on pressure driven flow and related heat transfer in microchannels with surface chemical reaction. (March 2019)

• Record Type: Journal Article
• Authors: Mo, Xiaobao; Hu, Xuegong
• Is Part Of: International journal of heat and mass transfer. Volume 130(2019)
• Page Start: 813
• Page End: 820
• Publication Date: 2019-03
• Subjects: Electroviscous effect -- Electrical double layer -- Fluidic flow -- Heat transfer -- Surface chemical reaction; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2018.10.113
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Electroviscous effect on pressure driven flow and heat transfer is studied. The surface chemical reaction in microchannels is considered. The boundary slip is considered. Three different electrical boundary conditions are compared. Abstract: This study investigates the fluidic flow and related heat transfer in a microchannel formed by two parallel plates. Uniform heat flux is applied at the walls with considering the surface chemical reaction, which determines the surface charge on the wall of the microchannel. Our results show that the pH and ionic concentration apparently affect the surface chemical reaction and the subsequent fluidic behavior and heat transfer in the microchannel, especially with the boundary slip. The dimensionless velocity and temperature increase with the ionic concentration. The difference of the dimensionless flow rate and the Nusselt number is obvious under three different electrical boundary conditions: constant surface charge density, constant zeta potential and MI model. Under the boundary slip, the dimensionless flow rate and Nusselt number decrease by 50% and 12%, respectively, with increasing pH under the MI model, but keep unchanged under constant zeta potential or surface charge model. The dimensionless flow rate and Nusselt number also increase with the ionic concentration due to weakened electroviscous effect. Meanwhile, the slip increases the influence of ionic concentration on the dimensionless flow rate and Nusselt number. The results of this work may guide the design and optimization of microfluidic devices.