Abdelilah Makaoui, Mohammed Amine Moussaoui, Ahmed Mezrhab
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引用次数: 0
Abstract
The multiple relaxation time lattice Boltzmann method (MRT-LBM) was used to study the flow of a pulsating hybrid nanofluid of copper and aluminium (Cu–Al2O3) and water containing two internal obstacles inside a heated microchannel. The effects of the Reynolds number (Re), Strouhal number (St), total nanoparticle volume fraction (φ), copper mixing ratio, and obstacle shape (rectangular vs. trapezoidal) were determined using the mean Nusselt number (Nu), friction factor (f), and performance evaluation criterion (PEC). Increases in φ and copper ratio enhanced effective heat transfer, resulting in an increase in Nū. Under identical operating conditions, this reached a maximum of 28% compared to water for φ = 4% and 75% copper. The inlet pulse produced a non-uniform response, with the optimal result occurring near St ≈ 0.8. Within this region, the periodic disturbance of the boundary layer and the regeneration of the thermal fluid near the wall were more effective. Increasing St led to a further decrease in net gain due to phase lag and incomplete thermal redevelopment within the cycle. Replacing the rectangular obstacle with a trapezoidal obstacles suppresses stagnation recirculation and promotes smoother reattachment. This improves the hydrodynamic thermal equilibrium, resulting in a maximum PEC≈1.35. These results provide design guidelines for the coordinated selection of hybrid configuration, pulse frequency, and barrier shape in microchannel heat sinks.
期刊介绍:
Thermal Science and Engineering Progress (TSEP) publishes original, high-quality research articles that span activities ranging from fundamental scientific research and discussion of the more controversial thermodynamic theories, to developments in thermal engineering that are in many instances examples of the way scientists and engineers are addressing the challenges facing a growing population – smart cities and global warming – maximising thermodynamic efficiencies and minimising all heat losses. It is intended that these will be of current relevance and interest to industry, academia and other practitioners. It is evident that many specialised journals in thermal and, to some extent, in fluid disciplines tend to focus on topics that can be classified as fundamental in nature, or are ‘applied’ and near-market. Thermal Science and Engineering Progress will bridge the gap between these two areas, allowing authors to make an easy choice, should they or a journal editor feel that their papers are ‘out of scope’ when considering other journals. The range of topics covered by Thermal Science and Engineering Progress addresses the rapid rate of development being made in thermal transfer processes as they affect traditional fields, and important growth in the topical research areas of aerospace, thermal biological and medical systems, electronics and nano-technologies, renewable energy systems, food production (including agriculture), and the need to minimise man-made thermal impacts on climate change. Review articles on appropriate topics for TSEP are encouraged, although until TSEP is fully established, these will be limited in number. Before submitting such articles, please contact one of the Editors, or a member of the Editorial Advisory Board with an outline of your proposal and your expertise in the area of your review.