Investigation of thermal and hydrodynamic behaviour of Al2O3-water nanofluid through a rough parallel plate

Abstract

The implementation of nanofluid within a preferred volume fraction in base fluid is one of the innovative and inexpensive methods of enhancing the thermal and hydrodynamic behaviour in terms of increased heat transfer rate and reduced pumping power. In the present paper, forced convection heat transfer and pumping power were studied for a rough parallel plate subjected to constant heat flux under turbulent flow condition. The investigation was performed for a wide range of Reynolds number 10,000 to 30,000 with Al2O3 nanoparticles volume fraction 1% to 5% dispersed in base fluid water and three different rough surfaces (relative roughness: 0.001, 0.002, and 0.003) were considered. Heat transfer performance was substantially improved more by employing roughness at the wall of the boundary than the smooth parallel plate and also for the increased more volume fraction of nanofluid than base fluid water. Augmentation was found significant at higher surface roughness and volume fraction by the virtue of superior thermo-physical properties of nanofluid up to 36.9% and 26.1% for the rough surface. Roughness did not increase the pumping power as its effect was mitigated by the nanofluid. 2% volume fraction of Al2O3-water nanofluid on 0.003 relative roughness that showed the superior behaviour for heat transfer enhancement with minimum pumping power requirement.