This study presents a numerical investigation of water-based magnetic nanofluids for the thermal management of compact power electronic devices under magnetohydrodynamic effects. The main objective is to evaluate how cooling-surface geometry, flow rate, heat flux, and magnetic field intensity jointly influence the thermal performance of water-based ferro-nanofluids. Six surface configurations were comparatively examined: flat, cube-finned, cylindrical-finned, triangular-finned, rectangular wall-finned, and sinusoidal wall-finned structures. Simulations were carried out using ANSYS Fluent under heat fluxes of 30, 40, and 50 kW m−2, volumetric flow rates of 1, 2, and 3 L min−1, and magnetic field intensities of 0.02, 0.03, and 0.04 T. Water-based magnetic nanofluids, including Fe3O4/H2O and MnFe2O4/H2O, were analyzed to determine their cooling effectiveness under coupled geometric and MHD conditions. The results demonstrate that surface geometry has a dominant influence on heat removal from the heated power-device surface. Among the investigated models, rectangular wall-finned and sinusoidal wall-finned geometries provided the most effective thermal performance compared with the flat reference geometry due to their larger heat-transfer area and improved flow guidance. The application of an external magnetic field further enhanced the thermal behavior of magnetically responsive nanofluids by improving temperature distribution and reducing local thermal accumulation. However, the MHD-induced improvement did not increase linearly under all operating conditions. At higher heat flux levels, the additional thermal benefit of the magnetic field became less pronounced, indicating a saturation tendency of magnetic field-assisted cooling. The novelty of this work lies in its combined comparison of multiple practical heat-sink geometries, water-based magnetic nanofluids, and externally controlled MHD effects under power-device cooling conditions. Unlike studies limited to a single channel, cavity, or simplified geometry, this work provides a comparative framework for identifying geometry-fluid-field combinations suitable for compact electronic-cooling applications. The findings show that optimized fin geometry and magnetic field-assisted ferro-nanofluids can improve thermal uniformity and cooling performance, while also defining operating conditions where MHD enhancement becomes limited.

Thermal efficiency analysis of water-based nanofluids in magnetohydrodynamic effects of power-device cooling

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2026年7月11日

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Muhammed Enes Mermer,
Ferhat Kilinc

摘要

This study presents a numerical investigation of water-based magnetic nanofluids for the thermal management of compact power electronic devices under magnetohydrodynamic effects. The main objective is to evaluate how cooling-surface geometry, flow rate, heat flux, and magnetic field intensity jointly influence the thermal performance of water-based ferro-nanofluids. Six surface configurations were comparatively examined: flat, cube-finned, cylindrical-finned, triangular-finned, rectangular wall-finned, and sinusoidal wall-finned structures. Simulations were carried out using ANSYS Fluent under heat fluxes of 30, 40, and 50 kW m⁻², volumetric flow rates of 1, 2, and 3 L min⁻¹, and magnetic field intensities of 0.02, 0.03, and 0.04 T. Water-based magnetic nanofluids, including Fe₃O₄/H₂O and MnFe₂O₄/H₂O, were analyzed to determine their cooling effectiveness under coupled geometric and MHD conditions. The results demonstrate that surface geometry has a dominant influence on heat removal from the heated power-device surface. Among the investigated models, rectangular wall-finned and sinusoidal wall-finned geometries provided the most effective thermal performance compared with the flat reference geometry due to their larger heat-transfer area and improved flow guidance. The application of an external magnetic field further enhanced the thermal behavior of magnetically responsive nanofluids by improving temperature distribution and reducing local thermal accumulation. However, the MHD-induced improvement did not increase linearly under all operating conditions. At higher heat flux levels, the additional thermal benefit of the magnetic field became less pronounced, indicating a saturation tendency of magnetic field-assisted cooling. The novelty of this work lies in its combined comparison of multiple practical heat-sink geometries, water-based magnetic nanofluids, and externally controlled MHD effects under power-device cooling conditions. Unlike studies limited to a single channel, cavity, or simplified geometry, this work provides a comparative framework for identifying geometry-fluid-field combinations suitable for compact electronic-cooling applications. The findings show that optimized fin geometry and magnetic field-assisted ferro-nanofluids can improve thermal uniformity and cooling performance, while also defining operating conditions where MHD enhancement becomes limited.