This book presents a comprehensive computational study on thermal destratification and free surface flow dynamics in aerated liquid storage tanks, focusing on the complex interactions between gas bubbles, liquid motion, and temperature distribution. Thermal stratification is a common phenomenon in large liquid storage systems where temperature gradients develop between the upper and lower layers of the liquid. Such stratification can lead to operational inefficiencies, safety concerns, and structural stresses in industrial storage tanks. Understanding and controlling this phenomenon is therefore of significant importance in many engineering applications. The book explores the mechanisms through which bubble dynamics and aeration processes influence the deformation of the free liquid surface and promote thermal mixing within the tank. Using advanced computational fluid dynamics (CFD) techniques, particularly the Volume of Fluid (VOF) method, the study analyzes bubble formation, rise, bursting behavior, and their role in destratifying thermally layered fluids. The numerical modeling framework incorporates governing equations of multiphase flow, surface tension effects through the continuum surface force model, and detailed computational domain configurations. A thorough literature review is presented covering experimental and numerical studies on bubbly flows, thermal stratification, and pressurization effects in fluid systems. The book also discusses solver formulation, model validation, and detailed simulation results that illustrate the influence of bubble-induced mixing on free surface deformation and temperature redistribution. Designed for researchers, graduate students, and engineers working in thermal engineering, fluid mechanics, and multiphase flow systems, this book provides valuable insights into the physics of aerated liquid systems and demonstrates how computational modeling can be effectively used to study and optimize destratification processes in industrial storage tanks.