3D Numerical Simulation of Nanofluid Laminar Forced Convection in A Channel with Localized Heating

A three-dimensional analysis is carried out to evaluate flow and heat transfer characteristics of Al2O3/water nanofluid in a duct with discrete heat sources. The heat sources are placed on the bottom wall of duct and generate much thermal energy that must be removed from the system. The remaining surfaces of channel are kept adiabatic to exchange energy between nanofluid and heat sources. In the present study the effects of Reynolds number ( Re=50, 100, 150, 200 and 250) and particle volume fraction ( =0 (distilled water), 0.5 and 2%) on the nanofluid thermo-physical properties, average heat transfer coefficient ( h ), pressure drop (P ) and wall temperature (Tw ) are investigated. The use of nanofluid can produce an asymmetric velocity along the height of the channel. The results show a maximum value 26% increase in average heat transfer coefficient and 275% increase in pressure drop for all the considered cases when compared to basefluid (i.e. water).It is also observed that the nanofluids thermal conductivity increases remarkably, especially near the heat sources, where higher hear transfer rate is required, and this may cause to apply them as smart materials in hot spots cooling.

discrete heat source, nanofluid, variable properties, heat transfer, pressure drop