Non-Newtonian power-law fluid flow over obstacles embedded inside a cavity

In this study, the flow of non-Newtonian fluid inside the lid-driven cavity with obstacle(s) is examined. The behavior of the fluid is described by the Ostwald-de Waele or power-law model. The lattice Boltzmann method (LBM) with a multiple-relaxation-time (MRT) collision model is employed to simulate complex fluid flows around the circular and square obstacles embedded inside a cavity. The stability of the present MRT-LBM algorithm in terms of so-called, cell-Reynolds number is investigated. The physics of flow structure and examinations of streamlines and vorticity contours are carried out for power-law as well as Newtonian fluids. For a single obstacle, the effects of various parameters such as Reynolds number (with respect to lid-dimension), obstacle size, power-law index, and shape of the obstacle on the flow characteristics and vortex formation are investigated. Furthermore, the effect of two square obstacles arranged in side-by-side and tandem manners inside the cavity is analyzed. Finally, the complex fluid flow over the multiple square obstacles embedded inside the cavity as a porous block for two blockage ratios is examined. Published under license by AIP Publishing.

Automated summary

This study focuses on the flow of non-Newtonian fluid inside a lid-driven cavity with obstacle(s), using the lattice Boltzmann method with a multiple-relaxation-time collision model to simulate complex fluid flows. Factors such as Reynolds number, obstacle size, power-law index, and obstacle shape are investigated for their effects on flow characteristics and vortex formation. Additionally, the impact of two square obstacles arranged in different configurations inside the cavity is analyzed, along with the examination of flow over multiple square obstacles as a porous block.