Experimental investigation of flow and heat transfer characteristics in tandem cylinders at high wall temperatures

The flow field around tandem heated cylinders is a subject of ongoing research due to its relevance in various engineering applications. This study investigates the influence of wall temperature and incoming flow velocity on the flow regime and heat transfer characteristics of tandem cylinders. Using a combined technique of Schlieren imaging and particle image velocimetry (PIV), the flow field was characterized over a range of incoming flow velocities (0.4 to 0.9 m/s) and cylindrical wall temperatures (423 to 673 K). The results indicate that higher wall temperatures promote a transition from the co-shedding regime to the shear layer reattachment regime. Conversely, increasing the incoming flow velocity leads to a transition from the shear layer reattachment regime back to the co-shedding regime. Beyond the flow regimes, the convective heat transfer was also quantified in the study, and a strong positive correlation was found between both wall temperature and incoming flow velocity and the convective heat transfer coefficient. These results demonstrate the significant influence of thermal and velocity conditions on the flow behavior and heat transfer in tandem cylinder arrangements.