Optimization of fluid flow and heat transfer analysis of peristaltic transport in fluid–particle suspension flow of Sisko fluid with electrokinetic force

This study investigates the electrokinetic transport of a non-Newtonian Sisko fluid containing rigid spherical particles, motivated by the need to understand liquid–solid suspensions in microfluidic and lab-on-chip applications. The problem is important because particle–fluid interactions under external electric fields strongly influence both flow regulation and heat transfer efficiency in such devices. A two-phase model is developed to describe the motion of the carrier fluid and dispersed particles. The electric double layer potential is linearized using the Debye–Hückel approximation, and the governing transport equations are simplified under the assumptions of long wavelength and low Reynolds number. Analytical solutions are obtained: the potential and temperature distributions are derived through a dedicated computational algorithm, while perturbation analysis yields the velocity field. The results show that the particle phase moves faster than the fluid phase, with the fluid velocity consistently lower than the particle velocity. Quantitatively, an increase in particle volume fraction reduces the heat transfer rate by about 16%, whereas enhancing the Helmholtz–Smoluchowski velocity leads to a 9% rise in heat transfer in a non-uniform channel. These findings confirm that rigid particles play a critical role in modulating flow and thermal performance. Validation against existing literature demonstrates consistency while highlighting the novelty of the present formulation. Unlike previous studies, this work provides a complete two-phase Sisko fluid framework under electrokinetic effects, offering new insights for optimizing flow control and improving heat transfer in lab-on-chip and related microfluidic technologies.