Mixed Convection in a Lid-Driven Cavity Filled with Nanofluids Using Single- and Two-Phase Eulerian Modeling Methods

The numerical simulation of the classical lid-driven cavity problem has been carried out to investigate the suitability of two-phase flow modeling techniques for nanofluids in computational fluid dynamics. The nanofluid investigated comprises water as base fluid and Al2O3 nanoparticles. Three types of the Eulerian-multiphase models, including the Eulerian, mixture, and volume of fluid (VOF) were compared with the single-phase model. The model equations were solved using ANSYS Fluent software for the nanoparticle volume fraction, the Richardson and Reynolds numbers in the range 0 ≤ ø ≤ 0.10, 10−4 ≤ Ri ≤ 102, and 1 ≤ Re ≤ 1000, respectively at a fixed Grashof number, Gr = 100. The results were compared with that of single-phase nanofluid modeling. There were similarities in the flow structure and temperature distribution for the single-phase and multi-phase methods when the convection is natural and mixed. However, the Nusselt number computed by the mixture and Eulerian models is higher than that of the single-phase and VOF models under the forced convection regime, with the percentage deviation from that of the single-phase as high as 10%. So, the three multiphase models are suitable for nanofluid convection problems and give results comparable to the single-phase model, especially under the natural and mixed convection regimes.