Narendran, G.Gnanasekaran, N.Arumuga Perumal, D.2026-02-042024Journal of Thermal Analysis and Calorimetry, 2024, , , pp. -13886150https://doi.org/10.1007/s10973-024-13947-2https://idr.nitk.ac.in/handle/123456789/21338In microchannel-based cooling devices, the response time exhibits distinctive variations owing to the heterogeneous integration of the heat source and the heat sink. These variations accompanied by flow maldistribution attributes to local temperature gradients are often referred to as flow-induced high-temperature zones and develop an uneven temperature distribution in microchannel heat sinks. To explore this phenomenon, we have designed an experimental setup featuring an in-house rectangular microchannel with an integrated heat spreader. In this study, we use a nanofluid comprised of graphene oxide (GO) and water as the working fluid, aiming to understand the thermo-hydrodynamics of the heat sink for various channel aspect ratios. The experimental results show that the heat wave propagation in the heat spreader is highly directional and influenced by the nanofluids flow rate and thermal conductivity. The study demonstrated that bulk fluid diffusion of GO nanofluid increased the temperature of the heat spreader by 30%. In the case of working fluid temperature, it increased by 35% for water and 52% for GO-0.12%. © Akadémiai Kiadó Zrt 2024.Thermal conductivity of liquidsCooling devicesGraphene oxidesHeat spreadersHeterogeneous integrationIntegrated microchannelMicro channel heat sinksNanofluid flowNanofluidsThermalWorking fluidTemperature distribution