Abstract
In this paper, we suggest a novel technique of heat taransfer augmentation in a complex duct, using a viscoelasticity of fluid. The heat transfer measurements and flow visualization experiments have been performed for a periodically contracted/expanded duct flow of surfactant/water viscoelastic fluid system. From the results, the recirculating regions behind backward-facing steps are observed to be markedly depressed when viscoelasticity is added to the fluid by surfactant addives. This causes successful heat transfer augmentation in a cavity of the expanded region, especially just behind a backward facing step, compared with the results of water flow. From this, the present method for heat transfer augmentation is found to be at least effective on heat transfer augmentation from bottom walls of a cavity in a periodically contracted/expanded duct flow.
