Experimental study on the thermophysical properties, heat transfer, thermal entropy generation and exergy efficiency of turbulent flow of ZrO2-water nanofluids

Abstract

The thermophysical, heat transfer coefficient, thermal entropy generation, frictional entropy generation, and exergy efficiency of ZrO2/DI-water nanofluids circulate through a tube under the turbulent flow was explored experimentally. The ZrO2 nanoparticles were developed through sol-gel technique. The thermophysical properties and heat transfer was measured in the temperature range 20–60 °C, volume loadings range 0.2–1.0% and Reynolds number range 2000–22000. Results shown at 1.0% vol. loading of nanofluid, thermal conductivity is increased by 24.96% at 60 °C; whereas the viscosity is raised by 45.57% at 20 °C, over base fluid. Moreover, the rise in heat transfer coefficient and Nusselt number of 1.0% vol. of nanofluid is about 46.30% and 31.65% with a friction factor penalty of 19.21% and pumping power penalty of 13.91% at a Reynolds number of 14575, against the water. Same way the thermal entropy generation is lowered by 31.65% and frictional entropy generation is raised by 19.2% at 1.0% vol. of nanofluid and at a Reynolds number of 14575. The exergy efficiency is also enhanced by 24.42% at 1.0% vol. and at a Reynolds number of 14575. Overall thermal performance factor is 1.242 -times larger than water, which indicates the ZrO2 nanofluids are beneficial heat transfer fluids.