© Shahzada Pamir Aly 2015 iii Dedicated to my mother, my father, my siblings and my teachers iv ACKNOWLEDGMENTS First of all I thank Allah, the Almighty and salutations be upon our beloved Prophet (P.B.U.H). It would have never been possible for me to write this acknowledgement today, if it weren‘t for ALLAH who gave me a chance to work at such a renowned institute. I feel blessed and am very grateful to my parents, who had always been a source of comfort with their continuous appraisal and unwavering encouragement throughout my life. King Fahd University of Petroleum and Minerals (K.F.U.P.M) is highly acknowledged for giving me an opportunity to carry out my graduate studies and providing me with an outstanding research environment. I am much obliged to my advisor and my mentor Dr. Khaled Saleh Al-Athel for his unrelenting support. I highly regard him for his patience with me and for coping up with my shortcomings. My sincere thanks are to Prof. Abul Fazal M. Arif who kept me going persistently. I also highly appreciate Dr. Sulaiman Pashah for giving me useful tidbits regarding my thesis. In the end I would also deeply like acknowledge Dr. Abbas Hakeem from CENT for allowing unhindered access to his lab, a seasoned lecturer Mr. Inam who shared his technical skills for the experimentation and the undergraduate student Khaled Hamed Al- Hamed for his unrelenting help with CT scanning. v TABLE OF CONTENTS ACKNOWLEDGMENTS ............................................................................................................. V LIST OF TABLES ........................................................................................................................ IX LIST OF FIGURES ....................................................................................................................... X LIST OF ABBREVIATIONS ................................................................................................... XIII ABSTRACT (ENGLISH) ......................................................................................................... XIV ABSTRACT (ARABIC) ........................................................................................................... XVI CHAPTER 1 INTRODUCTION ............................................................................................ 1 1.1 Metal Foams ............................................................................................................................... 1 1.2 Manufacturing and Applications ............................................................................................... 4 1.3 Motivation of Proposed Study .................................................................................................... 5 1.4 Objectives of the Proposed Study .............................................................................................. 8 CHAPTER 2 METAL FOAMS .............................................................................................. 9 2.1 Experimental .............................................................................................................................. 9 2.2 Computational Modeling ......................................................................................................... 15 CHAPTER 3 METHODOLOGY .......................................................................................... 21 3.1 Experimental Approach for Heat Sinks Performance ............................................................. 21 3.2 3D Modeling for Metal Foam Heat Sink Model ...................................................................... 25 CHAPTER 4 EXPERIMENTAL STUDY ........................................................................... 28 4.1 Metal Foam Heat Sink Samples Fabrication ........................................................................... 29 4.1.1 Solid heat sink .......................................................................................................................... 29 vi 4.1.2 Metal foam heat sink with thermal epoxy ................................................................................ 30 4.1.3 Metal foam heat sinks with thermal spray............................................................................... 30 4.2 Experimental Setup .................................................................................................................. 34 4.3 Experiments ............................................................................................................................. 36 CHAPTER 5 EXPERIMENTAL FINDINGS ..................................................................... 38 5.1 Results and Discussion ............................................................................................................. 38 5.1.1 Study A: Effect of Fin Type and Interface ............................................................................... 38 5.1.2 Study B: Single Fin Metal Foam Heat Sink ............................................................................. 40 5.1.3 Study C: Multiple Fin Heat sinks............................................................................................. 42 5.2 Summary .................................................................................................................................. 49 CHAPTER 6 METAL FOAM 3D MODELING ................................................................. 51 6.1 CT Scanning ............................................................................................................................. 52 6.1.1 Working Principle .................................................................................................................... 52 6.1.2 CT Imaging .............................................................................................................................. 55 6.1.3 Image Reconstruction .............................................................................................................. 59 6.2 Metal Foam Image Processing ................................................................................................. 63 6.3 Surface to volume/solid model ................................................................................................. 71 6.4 Summary .................................................................................................................................. 72 CHAPTER 7 NUMERICAL STUDY ................................................................................... 74 7.1 Computational Modeling of Heat Sinks ................................................................................... 74 7.2 3D Metal Foam Heat Sinks FE Simulations ............................................................................ 80 7.2.1 Convective heat transfer coefficient (h) calibration ................................................................. 80 7.2.2 Validation of FE Model ............................................................................................................ 86 7.2.3 General procedure of FE simulations ...................................................................................... 87 vii CHAPTER 8 NUMERICAL FINDINGS ............................................................................. 92 8.1 Metal Foam Heat Sinks Simulation Results ............................................................................. 92 8.2 Summary ................................................................................................................................ 104 CHAPTER 9 CONCLUSIONS AND FUTURE WORK ................................................. 106 REFERENCES.......................................................................................................................... 109 VITAE ....................................................................................................................................... 115 viii LIST OF TABLES Table 1 Thermo-mechanical properties of metal foam [3] ................................................ 4 Table 2 Material thermal properties [71] ........................................................................ 32 Table 3 Dimensions of Heat Sinks (mm) ........................................................................ 32 Table 4 Summary of the experimental findings .............................................................. 50 Table 5 Imaging parameters ............................................................................................. 59 Table 6 Reconstruction parameters .................................................................................. 60 Table 7 Heat Sink material properties ............................................................................. 80 ix LIST OF FIGURES Figure 1 Open Cell Metal Foam ...................................................................................... 2 Figure 2 Closed Cell Metal Foam ................................................................................... 2 Figure 3 Kelvin Unit Cell [45] ...................................................................................... 16 Figure 4 Weaire-Phelan Unit Cell [49] ......................................................................... 16 Figure 5 Unit Cells used in Literature for Metal Foam Modeling [51–54] ................... 18 Figure 6 Beam Model [11] ............................................................................................ 19 Figure 7 Voronoi tessellation method [57]...................................................................