Abstract A numerical study is performed to investigate the effects of an external uniform and non-uniform magnetic field on the optimal geometric design and thermal performance of a microchannel heat sink. Fe3O4 nanoparticles suspended in water is used as the cooling fluid. The optimization process has been utilized for three cases: (1) in the absence of the magnetic field, (2) in the presence of a uniform magnetic field, and (3) in the presence of a non-uniform magnetic field generated by a current-carrying wire. The numerical results are validated with existing experimental and numerical works. The results indicated that; for the off-design (non-optimal) geometries, imposing a uniform magnetic field decreased the thermal resistance up to 21% and improved the heat sink performance. However, for the on-design (optimal) geometries, no significant improvement was achieved by applying a uniform magnetic field. In this case, imposing the magnetic field did not change the optimal geometry of the heat sink compared to the reference case (in the absence of a magnetic field). On the other hand, imposing a non-uniform magnetic field improved the heat sink performance up to 10% for the on-design geometries. In this case, the optimal geometry of the heat sink changed in comparison with the reference case.

中文翻译：

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施加均匀和非均匀外磁场对微通道散热器优化设计的影响

摘要 通过数值研究研究了外部均匀和非均匀磁场对微通道散热器优化几何设计和热性能的影响。悬浮在水中的 Fe3O4 纳米颗粒用作冷却液。优化过程已用于三种情况：(1) 在没有磁场的情况下，(2) 在存在均匀磁场的情况下，以及 (3) 在存在由磁场产生的非均匀磁场的情况下载流线。数值结果通过现有的实验和数值工作进行了验证。结果表明；对于非设计（非最佳）几何形状，施加均匀磁场可将热阻降低 21% 并提高散热器性能。然而，对于设计中的（最佳）几何形状，施加均匀磁场没有取得显着改善。在这种情况下，与参考情况（在没有磁场的情况下）相比，施加磁场不会改变散热器的最佳几何形状。另一方面，对于设计几何形状，施加非均匀磁场可将散热器性能提高多达 10%。在这种情况下，散热器的最佳几何形状与参考情况相比发生了变化。