Experimental Measurements of Convective Mass Transfer from a Surface Due to a Bound Vortex Flow

Abstract

A host of manufacturing methods and mechanical processes depend on e cient convective mass and/or heat transfer. The use of ‘bound vortex’ impingement is shown to provide intense, localized, and well controlled heat and mass transfer enhancement. The bound vortex concept has been previously investigated by Vachon and Hitt as a means for enhancing surface shear stress for particulate dust removal applications. This study investigates the influence of bound vortex flow on the mass and heat transfer from an impinged surface over a range of flow conditions. Naphthalene sublimations techniques are employed to capture local mass transfer distributions and the Colburn analogy is used to interpret the results in terms of the local Nusselt number. Experimental flow conditions are recreated computationally and compare favorably with the experimental data. Convective mass and heat transport characteristics show that the bound vortex flow structure is capable of providing intense, localized, and well controlled transport enhancement. When compared to traditional a swirling flow impingement, an increase of 66% in peak Nusselt number and a 355% gain in average Nusselt value was observed for the optimal bound vortex condition.