Drag Reduction and Heat Transfer Augmentation of Surfactant Additives in a Two Dimensional Channel Flow

摘要

An experimental test is conducted to attempt heat transfer augmentation in the channel flow, which shows drag reduction. As is known, addition of small amount of surfactant to water can reduce turbulent frictional drag considerably. Many investigations have been carried out to apply this profit to district heating systems, but confirmed that the heat transfer is reduced simultaneously. For the application of this phenomenon to a heat exchanger, with considering the disproportion between the momentum and the heat transfer, special technology for heat transfer augmentation is needed. Then, in this study turbulence promoters were introduced, and the possibility of heat transfer augmentation with the promoter in the drag reducing flow was investigated.