Review on Drag Reduction and Its Heat Transfer by Additives

Abstract

Since its discovery more than 60 years ago, the drag reduction phenomenon has achieved many notable energy saving effects. These achievements have encouraged researchers to study drag reduction further and further so that it can be utilized better. But due to the complex characteristics of turbulent flow, recent theories cannot explain all the phenomena of drag reduction. To give an overview of drag reduction and corresponding heat transfer for further understanding, this paper summarizes the main advancements of drag reduction during these 60 years, including background, application, development, theory, and research methods of different drag reducers. Future directions of development are also discussed.