Numerical Study on Conjugated Laminar Mixed Convection of Alumina/Water Nanofluid Flow, Heat Transfer, and Entropy Generation Within a Tube-on-Sheet Flat Plate Solar Collector

Abstract

In this research, an inclined three-dimensional nanofluid-based tube-on-sheet flat plate solar collector (FPSC) working under laminar conjugated mixed convection heat transfer is numerically modeled. The working fluid is selected to be alumina/water (Al2O3/water) and results from heat transfer, entropy generation, and pressure drop points of view are being presented for various prominent parameters, namely volume fraction, nanoparticles diameter, Richardson and Reynolds numbers. According to the simulations, Nusselt number decreases as the Richardson number or volume fraction of the nanofluid rises, whereas heat transfer coefficient experiences an augmentation when volume concentration and the Richardson number surge. Also, data reveal that total entropy generation rate of the system declines when the alumina/water nanofluid is utilized inside the system as the volume fraction or the Richardson number increases. Additionally, it is found that increasing the nanoparticle volume concentration or the Richardson number diminishes the pressure drop considerably, whereas friction factor substantially proliferates as the Richardson number or volume fraction rises. Eventually, employment of larger alumina nanoparticles mean diameter eventuates in providing lower Nusselt number and apparent friction factor while it increases the pressure drop and heat transfer coefficient. Finally, comparing the efficiency of the presented FPSC design with those available in the literature shows a superior performance by the present design with its maximum occurring at 2 vol %.