عنوان مقاله English
نویسندگان English
In this research, counter-current two phase flow is investigated adiabatically in vertical Plexiglas tubes with internal diameters of 60 mm, 80 mm and 110 mm. All of tubes have the same height of 2 m. So far, there have been few studies on counter-current flows in large diameter tubes. Water and air flow downward and upward through the tubes, respectively. Superficial velocities of air and water ranges are 1.77-7.17 m/s and 0.05-0.11 m/s for 60 mm tube, 0.99-4.03 m/s and 0.03-0.09 m/s for 80 mm tube and 0.55-2.26 m/s and 0.01-0.05 m/s for 110 mm tube. In addition to reverse flow, other main regimes can be observed as slug, churn and annular in the tubes. Our efforts in drawing the flow patterns map were aimed at minimizing uncertainties at the boundaries. Based on the obtained experimental results, slug and annular regimes gradually comprise smaller regions of the flow map as the tube diameter increases. However, churn regime contains larger area of the flow pattern maps. Moreover, Kelvin – Helmholtz instability is observed in tubes and experimental and analytical results represent appropriate consequent in comparison. Eventually, validation of experimental flow patterns map accomplished by theoretical results.
کلیدواژهها English
