2025, 46(6): 717-729.
doi: 10.21656/1000-0887.450199
Abstract:
Curved microchannels exhibit significant advantages in electroosmotic flow and heat transfer, including increased electroosmotic flow velocities and improved heat transfer efficiencies. At the same time, nanofluids have received widespread attention due to their excellent heat transfer performances. However, current research on the electroosmotic flow and heat transfer mechanisms of nanofluids within curved microchannels remains insufficient. Herein, the effects of the geometry of curved microchannels on the electroosmotic flow and heat transfer characteristics of nanofluids in the microchannels were investigated at low zeta potentials and constant wall heat fluxes. The creeping Dean flow was considered, and the velocity field was kept in a straight line distribution due to no centripetal force. The semi-analytic solutions of velocity and temperature were obtained with the Fourier transform method, and the mathematical expression of Nusselt number Nu was derived based on the velocity and temperature solutions. The variation trends of the velocity, the temperature, and Nusselt number Nu with curvature ratio δ, nanoparticle volume fraction φ, and the ratio of the characteristic pressure velocity to the characteristic electroosmotic velocity ur, were analyzed, with the characteristics of the flow and heat transfer phenomena revealed. The results show that, Nusselt number Nu decreases with the pressure velocity and the curvature ratio, and increases with the nanoparticle volume fraction. The work provides an important reference for the design and application of micro and nano fluid devices, and helps to optimize the device performances and applications.
