Heat transfer to a falling viscoelastic fluid film

摘要

Steady heat transfer to water and viscoelatic fluid films falling down a vertical tube, for the case of uniform wall teat flux thermal boundary condition, was measured experimentally. The viscoelstic fluids studied were aqueous solutions of Praestol at 100, 200, and 500 ppm (by weight) concentration. The heat transfer to viscopelstic film was lower than the Newtonian prediction, at any given Prandtl number. A new correlation is proposed for Dimensionless laminar and turbulent heat transfer coefficient in terms of the Weissenberg Number, over a range of 300 ≤ Re_a≤6,500, and 6≤Pr_a≤30.