Liquid-gas flows are one of the most important form of multi-phase flow. These flow situations manifest widely in a whole range of industrial applications. These include pipeline systems for the transport of oil-gas mixtures, evaporators, boilers, condensers, different forms of submerged combustion systems, sewerage treatment plants, air-conditioning and refrigeration processes in industries, cryogenic plants etc. Liquid-gas systems are also very important in the meteorology and in other natural phenomena. Solution of the liquid-gas flow problems using the Computational Fluid Dynamics (CFD) has caught attention of many researchers and design engineers all over the world. This book is an attempt to approach the use of CFD in resolving the issues with the liquid-gas two phase flow design problems. The book will be helpful for scholars, engineers and researchers engaged in this field.