New correlations to predict the thermal and hydraulic performance of different longitudinal pin fins as vortex generator in miniature channel: Utilizing MWCNT-water and Al2O3-water nanofluids

Abstract

In this paper, a parameter as area modification factor is defined for the cross section shape of pin fins. The effect of this parameter on the thermal and hydraulic performance of different coolant fluids inside pin fin miniature channel is numerically investigated. This parameter amount is 90°, 82°, 75°, 68° and 59° that lead to the rectangular, trapezoidal of type (3), (4) and (5) and triangular fin. The MWCNT-water and Al2O3-water nanofluids are working fluids which are simulated by mixture two-phase model. The range of the Reynolds number and nanoparticles volume concentration are 300–2100 and 0–3vol.%, respectively. The results show that the thermal performance is enhanced much folds by using the nanofluid compared to that for the pure water inside the miniature channel with a slight increase in pressure drop penalty. The water flow and 1vol.% Al2O3-water nanofluid has the highest overall performance in the triangular pin fin miniature channel but MWCNT-water nanofluid has the highest and least overall performance in the trapezoidal pin fin of type (3) and triangular pin fin, respectively. New correlations are also suggested to predict the Nu number and friction factor of the different pin fin miniature channels.