Microscale heat transfer in single- and two-phase flows: scaling, stability, transition

Proper understanding of microscale transport phenomena is fundamental for the designer of microfluidic devices. For this reason, many studies have been conducted to analyse the behaviour of convective flow through microchannels, both in single-phase and in two-phase flow. A first glance of the literature, especially for single-phase flow, leads to the conclusion that up to now we have had an agglomeration of disparate conclusions. In many cases the experimental data in microchannels disagree with the conventional theory and empirical correlations, but they also appear to be inconsistent with one another. The present paper is an attempt to critically analyse the available results for liquid single-phase and flow boiling heat transfer, trying to provide some sort of base note in the melisma of published data.