Natural convection in a differentialy heated enclosure filled with low Prandtl number fluids with modified Lattice Boltzman method / S. Bawazeer, A.A. Mohamad, P. Oclon // International Journal of Heat ... więcej

Natural convection in a differentialy heated enclosure filled with low Prandtl number fluids with modified Lattice Boltzman method / S. Bawazeer, A.A. Mohamad, P. Oclon // International Journal of Heat and Mass Transfer [Dokument elektroniczny]. – 2019, Vol. 143, 15 s. : rys., tab., wykr. – Tryb dostępu: https://www.sciencedirect.com/science/article/pii/S0017931019305368?via%3Dihub. – Oznaczenie ref./art.: 118562. – Bibliogr. 25 poz., Abstr. – doi: 10.1016/j.ijheatmasstransfer.2019.118562. – ISSN 0017-9310

The convective motion in a three- and two- dimensional square cavity driven by a temperature gradient is analyzed. The cavity is filled with a low-Prandtl-number (Pr) fluid, typical for liquid metals. ... więcej

The convective motion in a three- and two- dimensional square cavity driven by a temperature gradient is analyzed. The cavity is filled with a low-Prandtl-number (Pr) fluid, typical for liquid metals. The vertical walls have constant but different temperatures, while the horizontal boundaries are adiabatic. Low Prandtl number exhibits strong non-linearity, where the advection term dominates the diffusion term in the momentum equations. Therefore, a Multi-Relaxation-Time, modified Lattice Boltzmann (MRT-LBM) approach is used to overcome the stability of the numerical solutions. Also, by using the mentioned method a wide range of Prandtl numbers, Pr, (0.01–0.5) and a wide range of Rayleigh numbers, Ra, (104 to 108) are investigated. It was found that the flow field exhibits periodic oscillations at the critical Rayleigh numbers, which are dependent on the Prandtl number. The periodic flow becomes aperiodic as the Prandtl number decreases and/or the Rayleigh number decreases. Also, the average Nusselt number are presented and correlated for the investigated range of the controlling parameters.