Computational Modeling of Thermodynamic Effects in Cryogenic Cavitation

Abstract

I am grateful to several individuals for their support in my dissertation work. The greater part of this work was made possible by the instruction of my teachers, and the love and support of my family and friends. It is with my heartfelt gratitude that I acknowledge each of them. Firstly, I would like to express sincere thanks and appreciation to my advisor, Dr. Wei Shyy, for his excellent guidance, support, trust, and patience throughout my doctoral studies. I am very grateful for his remarkable wisdom, thought-provoking ideas, and critical questions during the course of my research work. I thank him for encouraging, motivating, and always prodding me to perform beyond my own limits. Secondly, I would like to express sincere gratitude towards my co-advisor, Dr. Nagaraj Arakere, for his firm support and caring attitude during some difficult times in my graduate studies. I also would like to express my appreciation to the members of my dissertation committee Dr. Louis Cattafesta, Dr. James Klausner, and Dr. Don Slinn, for their valuable comments and expertise to better my work. I deeply thank Dr. Siddharth Thakur (ST) for providing me substantial assistance with the STREAM code and for his cordial suggestions on research work and career planning. My thanks go to all the members of our lab, with whom I have had the privilege to work. Due to the presence of all these wonderful people, work is more enjoyable. In particular, it was a delightful experience to collaborate with Jiongyang Wu, Tushar Goel, and Baoning Zhang on various research topics. v I would like to express my deepest gratitude towards my family members. My parents have always provided me unconditional love. They have always given top priority to my education, which made it possible for me to pursue graduate studies in the United States. I would like to thank my grandparents for their selfless affection and loving attitude during my early years. My wife's parents and her sister's family have been extremely supportive throughout my graduate education. I greatly appreciate their trust in my abilities. Last but never least, I am thankful beyond words to my wife, Neeti Pathare. Together, we have walked through this memorable, cherishable, and joyful journey of graduate education. Her honest and unfaltering love has been my most precious possession all these times. I thank her for standing besides me every time and every where. To Neeti and my parents, I dedicate this thesis! vi

Large eddy simulation of a sheet/cloud cavitation on a NACA0015 hydrofoil

“…More work is needed to verify it further, and future work on this model should be focused on (i) improving the pressure-density curve so as to describe real cases better; (ii) carrying out quantitative comparisons with experimental results published [31,33,[47][48][49]; and (iii) incorporating an energy equation to handle cavitating flow of cryogenic fluids [33], where the strong dependence of the vapor pressure on the local temperature has to be taken into account to correctly predict the extent of the cavitating region.…”

“…Here the hat denotes the predicted value; s þ k and s À k denote the backward and forward surface of a control volume, respectively; H + and H À correspond to the flux vector evaluated at the center of the backward and forward control volume, respectively and the subscript k is an index of cell surfaces [33].…”

“…In this theory, assuming that the local velocities are the same for liquid and vapor, the mixture density concept is then introduced and single phase equations for two-phase mixture of mass and momentum can be derived and solved. By comparison, the pressure-based method has the advantage that it can take into account other non-condensed phases [34] and gets accurate force results in case of stable cavitation simulation [31,33,35], but rare simulation results can be found so far for hydrofoils with large angles of attack, with large bubble clusters shedding, maybe due to the numerical difficulties. In contrast, the density-based method can simulate all types of (traveling-, sheet-, sheet/cloud-and super-) cavitation as well as the easiness of coupling with turbulence model [37][38][39][40][41], but it predicts less accurate force results than the pressure-based method [40,41].…”

“…Among the recently-developed physical models for unsteady cavitating flows can mainly be categorized along two algorithms: pressure-based [31][32][33][34][35] and density-based [36][37][38][39][40][41] methods. A pressure-based method considers two mass balance equations, one for liquid and one for vapor.…”

Thermal Effects on Cryogenic Cavitating Flows around an Axisymmetric Ogive

“…Despite the improvements in the approach, it is important to underscore the limitation that the above studies does not solve the energy equation in the domain. Ahuja [8] and Utturkar [9] recently solve the energy equation in the entire domain with dynamic update of material properties and reported numerical studies on cavitation using liquid hydrogen and liquid nitrogen. For the former, their pressure and temperature predictions over a hydrofoil geometry is not obtained well with the experiment in the leading edge.…”