Fluid flows are ubiquitous in our daily life, abounding in both nature and various engineering applications. About two-thirds of our Earth is covered by water, and we all live within an approximately 17 km thick invisible blanket of air called the atmosphere. Both air and water are essential for the survival of all life on Earth. The flow of air and blood in our body carries oxygen and nutrients to all our vital body parts, keeping them alive and functioning. We remain passive spectators to the immeasurable devastation of many precious lives and property caused by tornadoes and hurricanes in nature. We can never wipe out the horrible televised images of the unimaginable destruction caused by the 2011 tsunami in Japan. Most of us can relate to the scare during a flight when our plane encounters pockets of atmospheric turbulence. In 2012, our weather forecast models predicted well in advance the unusual westward turn of Hurricane Sandy, saving many lives in the New York and New Jersey area. In spite of the two-faced “beauty and the beast” display of fluid mechanics, it remains one of the most fascinating subjects in engineering and science. The continued research in various flow phenomena allows for a deeper understanding and more accurate predictions using state-of-the-art computational fluid dynamics (CFD) technology. By using this technology, we have acquired the ability to develop advanced designs of many fluid flow-related applications including commercial and military planes; submarines and cruise ships; automobiles, jet and rocket propulsion; oil and gas pipelines; gas turbines, steam turbines, pumps, compressors, and air-conditioning and refrigeration units; heat exchangers, artificial hearts and valves; dams and irrigation systems, and others.