Goktepeli, I.Atmaca, U.2025-01-102025-01-1020251064-2285https://doi.org/10.1615/HeatTransRes.v56.i2.10Different thermophysical property models for nanofluids and several dimensionless parameters have been compared in the case of heat transfer for laminar flow in a microchannel. Addition of nanoparticles, including Al2 O3, CuO, and TiO2, to water has been considered for volumetric concentrations up to ϕ = 7%. The numerical analyses have been conducted via the finite difference method for a transient regime. The heat transfer results have been obtained in terms of the interfacial heat flux, bulk temperature, and the Nusselt number. The parametrical effects of Péclet number values, wall thickness ratios, thermal diffusivity ratios, thermal conductivity ratios, and Brinkman number values have been evaluated. Based on the results, the influence of axial conduction has been clearly observed for lower Péclet numbers. Furthermore, the increment of the thermal conductivity ratio and the decrement of the wall thickness ratio have enhanced thermal performance. Nevertheless, the thermal characteristics have not been significantly influenced by the thermal diffusivity ratio. The viscous dissipation has altered the heat transfer direction due to the change in the Brinkman number. The required time to reach the steady state for numerical solution increased because of decreasing Brinkman number values. Heat transfer augmentation has been obviously obtained due to ascending nanofluid volumetric concentrations. The CuO nanoparticles have been recommended owing to their higher thermal performance for the fixed volumetric concentration. According to the thermophysical models compared for each type of nanoparticles, the models for Al2 O3 nanoparticles presented the closest results to each other. Nonetheless, it has been observed that one model for CuO nanoparticles and one model for TiO2 nanoparticles are inadequate. © 2025 by Begell House, Inc.eninfo:eu-repo/semantics/closedAccessBrinkman NumberMicrochannelNanofluidNusselt NumberPéclet NumberThermophysical Property ModelArticle10.1615/HeatTransRes.v56.i2.102-s2.0-85214515466