CHARACTERISTICS INVESTIGATION AND PARAMETRIC STUDY OF FLOW BOILING IN MICROGAP HEAT SINK

Abstract

Flow boiling in microgap offers several advantages, such as extremely high heat transfer rate in compact space with a smaller coolant flow rate, greater temperature uniformity across the heat sink and ease of fabrication and implementation. The objectives of this investigation on flow boiling in microgap channels are to (1) obtain better fundamental understanding of the flow boiling processes, (2) evaluate the effect of microgap dimension on the performance of microgap heat sinks, (3) evaluate the effect of surface roughness on the performance of microgap heat sinks, (4) compare performance between microgap and conventional straight microchannel heat sinks, (5) evaluate the microgap heat sink for instabilities and hotspot mitigation. This thesis presents an up to date summary of details of the confined to unconfined flow boiling transition criteria, flow boiling heat transfer and pressure drop characteristics, instability characteristics, two phase flow pattern and flow regime map and the parametric study of microgap dimension.