Dual streaming potential effects on EMHD mixed convective nanofluid flow with viscous dissipation and Joule heating

This study presents an analytical investigation of electroosmotic magnetohydrodynamic (EMHD) mixed convection flow of nanofluids in a vertical microchannel, incorporating viscous dissipation, Joule heating, and a dual streaming potential formulation. The model is relevant to biofluid transport systems, microreactors, and thermal regulation in microscale devices where internal heat generation and electrokinetic effects coexist. Water is used as the base fluid, while copper (Cu), tin oxide (SnO 2 ), and silicon dioxide (SiO 2 ) nanoparticles are considered to examine the influence of material properties. The governing nonlinear coupled equations for momentum, energy, and electric potential are transformed into dimensionless form and solved analytically using the Homotopy Perturbation Method (HPM). The formulation includes electroosmotic forcing, applied magnetic field, mixed convection, velocity slip, thermal slip, viscous dissipation, Joule heating, and dual streaming potentials, while magnetic induction is neglected in this model. The results show that viscous dissipation and Joule heating significantly elevate fluid temperature, leading to thicker thermal boundary layers and reduced heat transfer rates. The presence of dual streaming potentials reveals that only one component converges to the physically meaningful solution, ensuring electrokinetic consistency. Increasing Reynolds number enhances heat transfer, while higher Eckert and Brinkman numbers suppress it. Silicon dioxide nanofluid yields higher flow rates, whereas copper nanofluid produces stronger thermal effects. The study provides deeper insight into thermally driven EMHD nanofluid systems and offers guidance for efficient microfluidic heat management.