Publication

Abstract : A Steady state-laminar forced convective heat transfer has been simulated by Computational Fluid Dynamics (CFD) with a Single Phase Model (SPM), Multi Phase model & Diameter effects and also determined the effects of nanoparticles concentration and nanofluid flow rate through 3D rectangular duct under certain boundary condition (constant heat flux). The nanofluid contains Alumina nanoparticles of size 60nm diameter used for MPM which is mixed with base fluid (water) with volume fraction of 0% ≤ ȼ ≤ 5% and Reynolds number (Re) ranges from 250 ≤ Re ≤ 1000. ANSYS 18.0 has been used for simulation. Three cases of analysis have been carried out in which the thermal conductivity (k) and dynamic viscosity (µ) of nanofluids are determined using two sets of theoretical models and one set of experimental k & µ data from literature respectively. The nanoparticles which stay more dispersed in the base fluid due to increase in Reynolds number which improves HTC and also decreases the friction factor accordingly. Particular attention has been paid to the variation of heat transfer characteristics when the modeling approach is switched from SPM to MPM. It is revealed that higher heat transfer rates are observed in MPM. The results shows that the friction factor decreases and Nusselt number (Nu) increases when there is an increase in the flow rate and also increase in the volume concentration of the nanofluid, while the pressure drop increases only slightly. The increase in HTC is one of the most important aims for industry and researchers.