of questions and help on using MFIX and OpenFOAM. I acknowledge Dr. Muhle's help on Univation Technologies project. His insightful comments and suggestions on the annual reports and journal publications helped in exploring different aspects of research. A warm thanks to all my colleagues at Fox group: Sean, Maulik, Jason, Janine, Yanxiang, Qingluan, Wei. Also, I would like to thank Dr. Mehrani and Andrew from University of Ottawa, Canada for the many discussions on electrostatics and experimental data in laboratory scale fluidized-bed. I would like to thank my friends (Siva, Prasad, Prem, Vichu, Shibi, Sriram, Rakesh, Sambit, Siva Kin, ...) in Ames for all their help and memorable experiences. I am deeply indebted to my close friends (Hari, Ravi, RamaKrishna, Lakshmi Tata, GowriSankar, Thirumalesha, Bhoom) who motivated, supported and guided me at various stages of my life. Finally, I would like to thank my wonderful family. I thank my father Ramachandra Rao for instilling the importance of hard work and higher education. I am grateful to my loving mother Lakshmi for her patience and encouragement. I am thankful to my sister Sri and brother Hari for their love, support and motivation. I gratefully acknowledge the financial support from