EXPERIMENTAL INVESTIGATION OF HEAT-TRANSFER AND FLOW OVER BAFFLES OF DIFFERENT HEIGHTS

The phenomenon of flow separation in ducts with segmented baffles has many engineering applications, for example, shell-and-tube heat exchangers with segmented baffles, labyrinth shaft seals, laser curtain seals, air-cooled solar collectors, and internally cooled turbine blades. In the present work, an experimental investigation has been done to study the characteristics of the turbulent flow and heat transfer inside the periodic cell formed between segmented baffles staggered in a rectangular duct. In particular, flow field, pressure loss, and local and average heat transfer coefficients were obtained. The experimental runs were carried out for different values of Reynolds numbers and baffle heights (window cuts) at uniform wall heat flux condition along the top and bottom walls. The results indicate that the pressure loss increases as the baffle height does, for a given flow rate. Also, the local and average heat transfer parameters increase with increasing Reynolds number and baffle height. However, the associated increase in the pressure loss was found to be much higher than the increase in the heat transfer coefficient.