Effect of Non Uniform Flow Distribution on Single Phase Heat Transfer in Parallel Microchannels

The continuum assumption has been widely accepted for single phase liquid flows in microchannels. There are however a number of publications which indicate considerable deviation in thermal and hydrodynamic performance during laminar flow in microchannels. In the present work, experiments have been performed on six parallel microchannels with varying cross-sectional dimensions. A careful assessment of friction factor and heat transfer in is carried out by properly accounting for flow area variations and the accompanying non-uniform flow distribution in individual channels. These factors seem to be responsible for the discrepancy in predicting friction factor and heat transfer using conventional theory.