STUDY OF BUBBLE DYNAMICS IN CIRCULAR AND DIAMOND SHAPED PIN FIN MICROCHANNELS
Numerical study has been carried out to investigate the merits of microchannels having circular and diamond shaped pin fins. A bare channel has also been considered that compares the performance of proposed finned microchannels. Performance analysis in terms of bubble flow behaviour, augmentation of heat transfer and pressure drop has been done. Continuous stream of confined air bubbles have been modeled using customized patching technique. Bubbles are generated by patching air volume fraction at the channel upstream (in developed flow region of the channel) with a constant generation frequency. Simplified modeling of single row of each channel has been carried out for Reynolds number Re = 100-200 and heat flux q = 50-100 kW/m2. Results show that finned microchannels modify the bubble dynamics as it continuously deforms along the flow direction. Such flow behavior in microchannel heat sink may be considered as favourable to suppress instability and enhance heat transfer rate. However, it also offers higher pressure drop compared to bare channel.