Non-Fourier heat transfer of Maxwell nanofluids with couple stress driven by alternating-current electroosmotic flow and oscillatory pressure-driven flow based on the dual-phase-lag model in parallel plate microchannels

This study investigates the heat transfer of Maxwell nanofluids with couple stress driven by alternating-current electroosmotic flow and oscillatory pressure-driven flow in parallel-plate microchannels. We develop an analytical model that couples the dual-phase-lag non-Fourier heat conduction model with a couple stress viscoelastic fluid model. Derived from a dimensionless description, the closed-form solution for the temperature field within the channel is obtained by applying characteristic function expansion and Laplace transform methods. In addition, the variation of the Nusselt number is addressed. Moreover, the impact of several dimensionless parameters (such as the oscillating Reynolds number Re, the thermal relaxation time τq, and the temperature relaxation time τt) on flow and heat transfer performance is demonstrated through graphical representations. The results indicate that within the selected parameter range of this study, significant thermal wave oscillations and inhibitory diffusion effects emerge in the temperature field as the oscillatory Reynolds number increases. Furthermore, prolonged thermal relaxation time causes delayed heat flux responses, resulting in higher temperature peaks near the wall surface. A delay in the establishment of the temperature gradient, which results from an excessively long temperature relaxation time, causes a gradual temperature increase near the wall and a decrease in the channel interior. When the thermal relaxation time is less than or approximately equal to 1, the reflection and superposition of local thermal waves can enhance heat transfer performance. Conversely, when the thermal relaxation time is significantly greater than 1, excessive thermal lag leads to a sustained decline in heat transfer performance. The findings of this study will provide valuable guidance for designing thermal management systems in microdevices.