Influence of Transverse Flat Baffles on Heat Transfer Augmentation in a Confined Rectangular Channel

Abstract

Heat transfer intensification finds its importance in many practices such as air conditioning, heat exchanger and refrigeration structures. On heat transfer augmentation many researchers conducted experimental and numerical investigations to develop various techniques and methods. Heat transfer enhancement techniques are used to nurture the heat transfer rate without disturbing the complete performance of the system. The energy transport is considered enhanced if the flow is agitated and mixed well. This is the fundamental principle in the development of enhancement techniques that generate swirl flows. Nowadays, baffle inserts have widely been applied for improving the convective heat transfer in various applications due to their effectiveness, low cost and easy setting up. In proposed work an array of straight flat baffles was mounted transversely to the direction of air flow in a rectangular cross-sectioned duct and experiment was conducted for different Reynolds numbers ranging from 4938 to 6478. Investigations were performed to evaluate the influence of the presence of transverse straight flat baffles on the flow path. It was observed experimentally that the straight flat baffles greatly influences rate of heat transfer than that of the channel without baffles. The flow visualization for various Reynolds numbers also reports the significance of the presence of straight flat baffles in transverse directional flow. The influence of transverse flat baffles significantly effects the flow and found that increase in heat transfer rate and considerable pressure drop. Increase in Nusselt number, pressure drop and convective heat transfer coefficients were reported for various Reynolds number.