Augmentation of Heat Transportation by an Oscillatory Flow in Grooved Ducts

摘要

This paper deals with heat transportation by oscillatory flow in grooved ducts. The heat transportation rate, work rate, heat transportation efficiency, and dispersions of fluid particles and heat were analyzed with the computer code FLUENT. The frequency and tidal amplitude of the oscillatory flow were 0.05 Hz and 45 mm, respectively. The internal diameters of the contraction and expansion sections of the grooved ducts were 6.and 12 mm, respectively. The groove lengths varied from 0 to 40 mm and the pitch of the grooves was fixed at 10 mm. We found that: (1) The grooved duct with S=15 mm had the highest heat transportation rate, which was about 4.5 times that of the smooth round pipe. (2) The grooved duct with S = 20 mm had the greatest heat transportation efficiency, which was about 6.4 times that of the smooth round pipe. (3) Enthalpy transportation by the dispersion motion of fluid particles played a substantial role in the heat transportation of the grooved ducts with 5 mm ≤ S ≤ 40 mm. (4) The grooved duct with S = 10 to 15 mm had the greatest dispersion of fluid particles, which explained their having the greatest heat transportation rate.