A Computational and Experimental Investigation of Hybrid Microchannel Heat Sinks Employing Graphene-Water Nanofluids for Advanced Microelectronics Thermal Management

Abstract

Modern microelectronic devices face critical operational limits due to unprecedented localized heat fluxes exceeding 300?" W/cm" ?^2. Conventional single-phase cooling loops struggle to handle these extreme thermal densities without experiencing excessive pressure drops and thermal gradients. This paper presents a detailed computational and experimental analysis of a hybrid microchannel heat sink (HMHS) utilizing functionalized graphene-water nanofluids (0.1" vol" %" to " 0.5" vol" %). The hybrid geometry incorporates offset strip fins within primary micro-gap channels to promote boundary layer re-development and enhance chaotic advection. Computational Fluid Dynamics (CFD) simulations validated by physical experiments reveal that the integration of 0.3" vol" % graphene-water nanofluid at a Reynolds number of Re=1200 achieves a 38.4% reduction in total thermal resistance compared to pure water in smooth rectangular microchannels. Nusselt number increases by up to 52.1%, accompanied by a manageable pumping power penalty of 14.2%. The local temperature uniformity across the active substrate is improved by 4.2" K" , significantly mitigating localized hot-spot formation. Detailed parametric sweeps, hydrodynamic boundary layer assessments, thermal performance evaluation indices, limitations, and actionable future research scopes are comprehensively detailed.

KEYWORDS: Microchannel Heat Sink, Graphene-Water Nanofluid, Advanced Thermal Management, Computational Fluid Dynamics, Conjugate Heat Transfer, Microelectronics Cooling