Entropy Generation in Microchannels With Two-Phase Flow

The second law of thermodynamics is used to optimize microchannels sizes in two-phase flows. The overall performance of microchannels has been considered. The numerical solution of the conservation equations provides pressure drop and heat transfer rate. There is an aspect ratio which generates the lowest entropy generation rate. It indicates that decreasing the aspect ratio contributes to the reduction of entropy generation by heat transfer, because smaller channel width allows for less heat transfer rate. In contrast, decreasing the aspect ratio contributes the pressure drop increases and more entropy generation is produced. The results also show that, the lowest entropy generation moves towards the higher aspect ratio when the wall heat flux or vapor quality increases.