Thermal and entropic behaviour of unsteady nanofluid flow in a permeable-walled Couette system
DOI:
https://doi.org/10.24425/ather.2025.156847Abstract
This study examines the energy dissipation mechanisms in unsteady nanofluid flow confined between two permeable walls under a generalised Couette flow configuration, with a particular emphasis on entropy generation and convective heat transfer effects. Such an analysis is of growing significance in advanced thermal management applications, including industrial cooling processes, microelectronic systems, renewable energy technologies and biomedical devices, where nanofluids are increasingly employed to enhance thermal performance. The governing partial differential equations, derived from the conservation principles of mass, momentum, and energy, are solved numerically using a semi-discretisation finite-difference approach in conjunction with a Runge-Kutta-Fehlberg integration algorithm. Comprehensive results for velocity distribution, temperature field, skin friction coefficient, Nusselt number, entropy generation rate and Bejan number are presented and discussed. The findings reveal, among other trends, that increasing injection/suction rates and the Biot number reduce the Nusselt number, entropy generation rate and Bejan number at the stationary lower wall, while simultaneously enhancing these quantities at the upper moving wall. These results highlight the dual role of boundary conditions and thermal parameters in governing irreversibility, heat transfer efficiency and overall system performance. By offering insights into the minimisation of entropy-related losses, this work contributes to the design of more energy-efficient and sustainable nanofluid-based thermal systems.References
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