Heat transfer in gas-liquid and liquid-liquid two phase plug flow systems

Liquid-gas and liquid-liquid two phase flows are examined. It has been recently documented that gas-liquid segmented flows offer a thermal enhancement advantage over single phase flows, since the plug flow (Taylor flow) regime produces internal circulations which enhance radial transport. Additional strategies in liquid-gas and liquid-liquid cooling are being pursued with liquid cooled heat sinks. Proper heat transfer and pressure drop modelling are required in order to maximize the benefit of segmented fluid streams. This paper will present an overview of recent strategies and models, along with new results obtained by the authors for mini-channel heat sinks. These new results highlight some operational issues which need further attention.