Assessment strategies for mixing in very viscous gas-liquid two phase flows. Sharad Chand Ravinuthala I wish to express my heartfelt gratitude to the wonderful teachers I have had during the course of my education, the list of whom would always be lead by my father Sri. Ramakoteswara Rao. My success, if any, lies in direct correlation with their kind, nurturing and feeding my curiosity. I wish to thank Dr.Nithi Sivaneri for welcoming me to Morgantown, WV with a generous TA offer, my advisor Dr.Ismail Celik for his financial and academic support and Dr.Robin Hensel for the financial support during my initial days at WVU. This work would have never attained completion without the staunch support of my girlfriend Sucharitha Koleti and my brother Shailend Chand, the luxury of their unconditional love I always had. I wish to thank my friends Harsha Chand Kolli, Meghana Ramakumar and others for ensuring I always had a family this far from home. Then there are people who played a major role in making my academic life at WVU memorable. I would like to extend my heartfelt gratitude to the following friends starting with Dr.Raju Pakalapati who helped me find my feet at the CFD & AMP centre; Dr. Steve Rowan for his assistance with experiments; Dr. Gusheng Hu for his timely correspondence on matters concerning the DREAM code, Sergio Escobar for his genuine helping nature that I found infectious; Jose Escobar for his wonderful insights on issues that gave me a hard time and whose level of rigour I always found inspiring; Hayri Sezer whose 'Beautiful Mind' I had the good fortune to experience, with him I could discuss everything from evolution to philology and from quantum computing to computational finance; Gennaro Campitelli, in depth discussions with him about aerodynamics and Formula 1, and the daily technical banter helped me remind myself, during trying times, the primary reason why I had signed up to be a researcher in this field and why I was staying up late. Lastly, I would like to thank my committee members Dr.Wade Huebsch and Dr. John Kuhlman, a special thanks to Dr. Kuhlman for his famous "Introduction to Turbulence" course, attending which I consider one of the high points of my graduate life.