Flow patterns and bifurcations in a Z-shaped cavity part II: Refinement of corner and effect of Reynolds number

This research builds upon Çelik’s earlier study [1], which explored various flow patterns and constructed a bifurcation diagram for the flow with Stokes approximation in a Z-shaped domain driven by dual lids. In this study, enhanced solutions near the re-entrant corner are initially derived using the asymptotic matching technique. These solutions direct attention towards a comprehensive analysis of flow structures and behaviors at the re-entrant corner point. The formation and bifurcation of the separation bubble that appears near the corner is investigated in detail. Subsequently, the (h1, h2) control space diagram, which was previously developed on the basis of cavity height parameters, is recreated for a Reynolds number of 50. Additionally, the impact of the Reynolds number (Re) on vortex formation is analyzed. The findings indicate that at Re = 50, distinct flow patterns occur, and an increase in the Reynolds number accelerates vortex formation, leading to earlier transitions in flow topology and more complex bifurcation scenarios.