Enhancing heat transfer and minimizing entropy generation with mono and hybrid nanofluids: An experimental study

The article extensively studies heat transfer enhancement and entropy generation minimization using mono and hybrid nanofluids. Three nanofluid types were investigated:SiO2/Water, MgO/Water mono nanofluids, and SiO2-MgO/Water hybrid nanofluids, all at 0.03% mass concentration. Testing involved different fluid flows at varying mass flux from 66.35 to 597.13 kg/m2s through an uniformly heated tube subjected to a constant heat flux of 9,673W/m2. Variation in SiO2:MgO mass ratio (2:3, 1:1, 3:2) was considered. Results showed heat transfer improvement in MgO/Water mono and SiO2-MgO/Water hybrid nanofluids, while SiO2/Water mono exhibited no enhancement. The pressure drop increased from 0.007 to 0.310 bar with the increase in mass flux of the flow. However, it remained consistent for all fluids. Total entropy generation analysis revealed reduced values for hybrid and MgO/Water mono nanofluids in the range of 83.43-86.71% with the rise in mass flux flow rate. Whereas, SiO2/Water mono nanofluid exhibited 90.76% reduction in total entropy generation with the rise in mass flux. However, the SiO2/Water displayed higher values of total entropy generation from any other working fluid in the experiment. When compared to water, hybrid and MgO/Water mono nanofluids showed reduced total entropy generation. The SiO2-MgO/Water hybrid nanofluid at 2:3 mass ratio stood out with a 94.25% heat transfer coefficient enhancement and 48.08% entropy generation minimization at 287.50 kg/m2s mass flux. Finally, the exergetic merit analysis recommends SiO2-MgO/Water hybrid nanofluid at 2:3 mass ratio for superior heat transfer and entropy minimization in industrial applications, holding potential for enhanced heat transfer systems.