Assessment of turbulent flow and heat transfer of AL۲O۳-Water nanofluid in unconfined slot impinging jet configurations

A numerical approach is performed to simulate the turbulent flow and heat transfer of AL۲O۳-Water nanofluid in unconfined slot impinging jets for different particle volume fractions of the considered nanofluid, Φ, equal to ۰, ۱, ۴ and ۶. Moreover the jets exit Reynolds numbers range from ۵۰۰۰ to ۲۰۰۰۰ and the dimensionless geometric ratios of the jet configurations, H/W, (jet to impingement plate distance divided by jet orifice width) are considered to be ۶, ۱۰ and ۱۵. The flow is turbulent, two-dimensional, steady state and incompressible. Turbulent fluctuations in the velocity field are modeled using the Reynolds Averaged NavierStokes methodology and the numerical computations are validated against experimental data available in the literature. Results show that both Nu number and wall shear stress on the impingement plate increase with the increments of the nanoparticle volume fractions and the jet Re numbers. However increment of the jet to plate distance has an adverse effect on the heat transfer and friction factors of the impingement plate. The velocity profiles as a function of the dimensionless vertical and horizontal distance from the impingement zone uphold the trend of the Nu and wall shear stress distribution along the impingement plate.

Keywords:

Nanofluid , Impinging Jet , Particle Volume Fraction , Jet Reynolds Number , Nusselt Number , wall shear stress