E-raamat: Flow Boiling in Expanding Microchannels

This Brief presents an up to date summary of details of the flow boiling heat transfer, pressure drop and instability characteristics; two phase flow patterns of expanding microchannels. Results obtained from the different expanding microscale geometries are presented for comparison and addition to that, comparison with literatures is also performed. Finally, parametric studies are performed and presented in the brief. The findings from this study could help in understanding the complex microscale flow boiling behavior and aid in the design and implementation of reliable compact heat sinks for practical applications.

Chapter 1: Introduction 1.1 Background 1.2 Objectives References Chapter 2: Flow Boiling Heat Transfer and Pressure Drop Characteristics in Expanding Microgap Channel 2.1 Experimental Setup and Procedure < 2.2 Bubble characteristics in flow boiling expanding microgap heat sink 2.3 Comparison of pressure drop between expanding microgap heat sinks 2.4 Comparison of boiling curves between expanding microgap heat sinks 2.5 Comparison of local flow boiling heat transfer coefficient between expanding microgap heat sinks 2.6 Comparison of microgap heat transfer coefficient data with literature 2.7 Comparison of wall temperature uniformity between expanding microgap heat sinks 2.8 Conclusions References Chapter 3: Flow Boiling Instabilities in Expanding Microgap Channel 3.1 Mass flux effects on flow boiling instabilities in expanding microgap channel 3.2 Heat flux effects on flow boiling instabilities in expanding microgap channel 3.3 Microgap size effects on flow boiling instabilit

ies in expanding microgap channel 3.4 Conclusions References Chapter 4: Flow Boiling Heat Transfer, Pressure Drop and Instabilities in Straight and Expanding (Sloping Fin) Microchannels - A Comparative Study 4.1 Experimental Setup and Procedure 4.2 Flow boiling regimes and bubble dynamics in straight and sloping fin microchannels 4.3 Comparison of boiling curves between straight and sloping fin microchannels 4.4 Comparison of heat transfer coefficients between straight and sloping fin microchannels 4.5 Comparison of pressure drops between straight and sloping fin microchannels 4.6 Comparison of instabilities between straight and sloping fin microchannels 4.7 Conclusions References Chapter 5: Flow Boiling Performance in Scaled Up Expanding Channel Geometries: Stepped Fin Minichannels 5.1 Experimental Setup and Procedure 5.2 Comparison of boiling curves between straight and stepped fin minichannels 5.3 Comparison of heat transfer coefficients between straight and stepped fin minic

hannels 5.4 Comparison of pressure drops between straight and stepped fin minichannels 5.5 Comparison of wall temperature uniformity between straight and stepped fin minichannels 5.6 Conclusions References Chapter 6: Closure Appendix A: Uncertainty Analysis Appendix B: Data Reduction