Characteristics of the Vortical Structure in a Square Cavity with a Central Obstacle at Different Reynolds Numbers

Many researchers investigated different ways of improving the mixing inside a square lid-driven cavity by proper modification of the cavity geometric configuration. The present paper investigates the characteristics of the vertical structure inside a lid-driven square cavity with a central obstacle at different Reynolds numbers. The Multiple-Relaxation-Time Lattice Boltzmann Method (MRTLBM) is used to model the flow at Reynolds numbers between 100 and 1000. The results show that the position and shape of the main cavity is highly sensitive to the flow Reynolds number while the two lower side vortices are not affected by the change of the Reynolds number or the presence of the obstacle compared to the standard lid-driven cavity case. The reported results were verified against the standard lid-driven cavity case and showed good agreement. The results also show that adding a central obstacle to the standard cavity configuration can dramatically enhance its mixing capability. The reported results have significant importance for the enhancement of the mixing mechanisms inside the cavity for heat and mass transfer applications.