Vortex Shedding and Confined Vortices Behind an Isothermal Plate Positioned in a Parallel-Plate Duct

Abstract

Abstract. This study investigates turbulent flow and heat transfer in a high-aspect-ratio rectangular duct partially obstructed by a centrally positioned isothermal plate. Using a two-dimensional numerical model, the flow and thermal fields are analyzed over a range of Reynolds numbers (5000–80,000) and blockage ratios (h/H = 1/6 to 2/3). The heat transfer coefficients on the upstream and downstream faces of the plate are computed and compared with experimental data from the literature. Vortex shedding and recirculation patterns are captured and visualized. A key finding is the suppression of vortex shedding at high Reynolds numbers due to the formation of planar jets through the blockage gaps, which leads to a transition where jet flow dominates and suppresses vortex shedding. The results demonstrate consistent trends in Nusselt number variation, providing insight into the thermal behavior of obstructed duct flows.