Document Type : Research Paper


1 Petroleum Engineering Dept., Kerbala University, Karbala 56001, Iraq.

2 Mechanical Engineering Dept., University of Technology-Iraq, Alsina’a Street, 10066 Baghdad, Iraq.


A significant heat flux affects the efficacy and durability of most equipment. Cooling these devices is the primary concern, prompting specialists to propose and investigate various solutions. For these applications, microchannels are regarded as a possibility. Experiments were conducted in this study to determine the effect of an electroplating coating on the characteristics of a single-phase flow. As the working fluid for the experiments, deionized water was used. During the investigations, a microchannel of 0.3mm width and 0.7mm depth with an average roughness of 18.64 nm was machined; the inlet temperature was maintained at 30°C, and the Reynolds number ranged from 109.2 to 2599. According to the results, the correlation between the fanning friction factor and laminar and turbulent flows can predict experimental findings with high precision. In addition, an increase in the Nusselt number correlates with an increase in the Reynolds number.When compared to a conventional microchannel, the models with an Al2O3 cladding have a fanning friction factor that is much greater. According to the results, a reliable correlation can be used to precisely estimate the friction factor of typical Al2O3-coated microchannels. The results demonstrated that the average value of the maximum thermal performance value was approximately 1.19 at low Reynolds numbers between 240-480 and then decreased as Reynolds numbers increased.

Graphical Abstract


  • An experimental study was conducted for single-phase flow in the microchannels.
  • The heat transfer performance of materials coated with Al2O3 is enhanced for all Reynolds numbers.
  • The fanning friction factor for Al2O3-coated microchannels is 3.65% greater than that of ordinary microchannels.
  • Nusselt number of microchannel models coated with Al2O3 was 11.07 percentage points higher than that of the normal microchannel.


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