Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8067772 | Annals of Nuclear Energy | 2016 | 11 Pages |
Abstract
In the present research, a two-phase flow system is designed, manufactured, assembled and adjusted to study two-phase flow behavior isothermally. Test sections are tubes standing in vertical position and are made of transparent acrylic with inner diameters of 40Â mm and 70Â mm. Two axial locations of 1.73Â m and 3.22Â m are chosen for data acquisition. Flow pattern maps are presented for both tubes. Effects of tube diameter and axial location on pattern transition boundaries are investigated. Air and water are chosen as working fluids. The range of air and water superficial velocities are 0.054-9.654Â m/s and 0.015-0.877Â m/s for the 40Â mm diameter tube, but these values are 0.038-20.44Â m/s and 0.036-1.530Â m/s for 70Â mm diameter tube. The results show that for both tubes, increasing axial location does not affect flow transition boundaries significantly. However, slug pattern region shrinks considerably by changing tube diameter from 40Â mm to 70Â mm. Using image processing techniques, recorded high speed movies were investigated accurately. As a result, bubbly flow in the 40Â mm tube can be divided into three sub-patterns as dispersed, agitated and agglomerated bubbly. Also, two types of slug pattern are also recognized in the same tube diameter which are called small and large slugs. Semi-annular flow is observed as an independent pattern in the 70Â mm tube that does not behave as known churn or annular patterns.
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Authors
M.R. Ansari, R. Azadi,