Numerical simulation of Electrokinetically Driven Peristaltic Pumping of Silver-Water Nanofluids in an asymmetric microchannel

• Published in: Chinese journal of physics (Taipei) Vol. 68; pp. 745 - 763
• Main Authors: Akram, Javaria, Akbar, Noreen Sher, Tripathi, Dharmendra
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2020
• Subjects: Debye-Hückel approximation; Electroosmosis; Mixed Convection; Modified Buongiorno model; Poisson-Boltzmann ionic distribution; Viscous dissipation; Debye-Hückel approximation; Mixed Convection; Viscous dissipation; Poisson-Boltzmann ionic distribution; Electroosmosis; Modified Buongiorno model
• ISSN: 0577-9073
• DOI: 10.1016/j.cjph.2020.10.015

•Here the electroosmotically aided peristaltic pumping of aqueous nanofluid is investigated.•A modified Buongiorno nanofluid model together with Corcione's model is employed.•Silver nanoparticles are dispersed in the water to prepare silver-water nanofluid.•A comparison between Corcione's model and the Maxwell model is shown.•Maple 17 was used to compute the numerical solution of the nonlinear problem. This article intends to focus on the theoretical and numerical investigation of the peristaltic pumping of water-based silver nanofluid in the presence of electroosmotic forces. The investigation is carried out in an asymmetric microchannel subject to the influence of mixed convection and viscous dissipation. No-slip boundary conditions for velocity, temperature, and nanoparticle volume fraction are imposed on channel walls. The lubrication approach is utilized to simplify the normalized constitutive equations. The distribution of electric potential in the electric double layer is characterized by Poisson-Boltzmann ionic distribution which is further linearized by Debye-Hückel approximation. Nanofluid properties are predicted by a combination of the Buongiorno two-phase mixture model and homogeneous flow model. Additionally, the effective thermal conductivity and dynamic viscosity of silver-water nanofluid are characterized by the Corcione model. Silver nanoparticles of 20nm diameter are utilized in this suspension. The transformed set of nonlinear and coupled equations is numerically executed for axial velocity, temperature, and nanoparticle volume fraction by employing the mathematical software Maple 17. Pumping and trapping phenomena are also investigated. A comparison between the thermal conductivity of nanofluid predicted by the Corcione model and the Maxwell model is further presented. The influence of various flow parameters is outlined through graphical results. It has been observed that the thermal conductivity of silver-water nanofluid enhances with increasing nanoparticle volume fraction and temperature but decreases for larger sized nanoparticles. Moreover, the heat transfer rate rises significantly when smaller silver nanoparticles are suspended in water. Furthermore, the temperature of nanofluid is directly related to the Debye length parameter and the Helmholtz- Smoluchowski velocity parameter.