HEAT TRANSFER ENHANCEMENT DURING POOL BOILING OF WATER OVER HORIZONTAL AND VERTICAL TUBES WITH MICRO STRUCTURED SURFACES

Pool boiling is a stable and an efficient method for transferring large quantities of heat. This mode of heat transfer is used in a wide range of applications, including steam generation in boilers, petrochemical, pharmaceutical, cryogenic and many other industrial processes. It also holds promise for cooling of microelectronic devices, such as lasers, microprocessors and others. The objective of this work is to investigate the heat transfer augmentation due to an array of micro structured surfaces over a circular tube. The effects of horizontal and vertical orientation of the tubular test section on heat transfer enhancement are also studied. The bubble nucleation, growth and interactions over the micro structured surfaces are analyzed using high speed cameras to understand the bubble dynamics.