Investigations are conducted to understand the heat transport and fluid flow mechanisms in microchannel heat sinks. Single-phase experiments are performed with copper microchannels to explore the validity of classical correlations based on conventional-sized channels for predicting the heat transfer behavior in single-phase flow through rectangular microchannels. Numerical predictions obtained from computational fluid dynamics (CFD) analyses of the three-dimensional conjugate heat transfer process in a microchannel heat sink under classical, continuum assumptions were found to be in good agreement with the experimental data, suggesting that a conventional analysis approach can be employed in predicting heat transfer behavior in microchannel...