TURBULENT FORCED CONVECTION NANOFLUID FLOW OVER AN INCLINED FORWARD-FACING STEP

摘要

In this investigation, turbulent forced convection nanofluid flow with water as base fluid, Al and Cu as nanoparticles over an inclined forward-facing step is numerically studied in detail. CFD simulations were performed for a heated forward-facing step channel with different step lengths, and different inclination angles of the step and flow Reynolds number with ranges of 20 degrees <= theta <= 80 degrees and 30,000 <= Re <= 100,000, respectively. The concentrations of Al2O3 and CuO nanoparticles were varied from 1% to 4% with a particle diameter of 50 nm. For the CFD simulation of the turbulent two-phase nanofluid, the continuity, momentum, and energy equations were solved by a mixture method using the standard k-epsilon turbulence model. The effects of nanoparticle volume fraction, step length, and inclination angle at different Reynolds numbers on heat transfer were compared with that of the base fluid (water). The heat transfer rate improves with the increment of nanoparticle volume fraction, step length, inclination angle, and Reynolds number. Numerical outcomes revealed that Al2O3/water nanofluid has a higher influence of heat transfer compared with CuO/water nanofluid. The highest heat transfer enhancement was almost 26% and 19% for Al2O3/water and CuO/water nanofluids in comparison with the base fluid, respectively. A correlational equation has been suggested to forecast the mean Nusselt number as functions of various parameters of the inclined forward-facing step.