دراسة تجريبية وعددية لجريان ثنائي الطور في قناة توسعية/تقلصيه مستطيله مضلعة

EXPERIMENTAL AND NUMERICAL STUDY OF TWO-PHASE FLOW IN THE RIBBED DIVERGENT CONVERGENT RECTANGULAR DUCT

    Two-phase flow in the ribbed divergentconvergent rectangular duct for two cases: upward vertical and inclined was studied in this thesis. There are two working fluids used in this instigation, water and air. Experimental and numerical studies were performed to test the influence of increased air and water discharges on the pressure distribution and differential pressure through the divergentconvergent section. Also, the effect of increasing the divergent/ convergent angle on the pressure difference across the divergent/convergent section was studied. All sets of the experimental data in this study are obtained by using a pressure transducer and visualized by a video camera. Water inlet discharges used were between (5-20 L/min), and air discharges were between (5.833-16.666 L/min). Two testing channels with divergentconvergent angles (10 and 15 degrees) were used. The results indicated that the pressure along the testing channel raised as water and air discharge increased. For the divergent section, it was observed that; as the divergence opening angle increased, the pressure recovery decreased. While in the case of the convergence section, the pressure drop increased when the convergence angle increased. Computational fluid dynamics for a three-dimensional model was simulated with ANSYS FLUENT 18 depending on the operating condition obtained experimentally and governed by equations of volume of fluid (VOF) for Eulerian multiphase flow model and turbulence RNG model. A numerical study was conducted to study the effect of ribs on the flow behavior and pressure recovery. In the case of ribs absence, it was noted that; the value of the recovery of the pressure across the divergence section was higher than the case of ribs presence by (8.333%). An agreement was observed between the experimental and numerical values of pressure with a maximum deviation rate of (9 %). also, a similarity was observed in the flow behavior between experimental and numerical work.