The flow characteristics of upward gas-liquid two-phase flow through a vertical sudden contraction pipe is an area that has been less studied experimentally and numerically and that is still little known. The drag and its reduction for an upward bubbly two-phase flow in a sudden contraction pipe are investigated. Vortices are generated just prior to and after contraction and they significantly affect the flow characteristics. A simple and economical method to control and smoothen the flow is proposed by mounting a small obstacle (ring) upstream the contraction. The effects of ring position, Reynolds number and volumetric gas flow rate are examined and positive results were seen in all flow conditions. Moreover, the pressure fluctuation phenomenon and its control downstream the contraction was considered.
JSME international journal. Ser. 1, Solid mechanics, strength of materials
JSME international journal. Ser. A, Mechanics and material engineering
JSME international journal. Ser. 3, Vibration, control engineering, engineering for industry
JSME international journal. Ser. C, Dynamics, control, robotics, design and manufacturing
JSME International Journal Series A Solid Mechanics and Material Engineering
JSME International Journal Series C Mechanical Systems, Machine Elements and Manufacturing