Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

1 Publication

A new database on the evolution of two-phase flows in a large vertical pipe

Lucas, D.; Beyer, M.; Szalinski, L.; Schütz, P.

A comprehensive database with high quality was obtained for stationary upward air-water flows in a vertical pipe with an inner diameter of 195.3 mm using the wire-mesh sensor technology. During the experiments the sensor was always mounted on the top of the test section while the distance between gas injection and measuring plane was varied to up to 18 different L/D by using gas injection chambers at different vertical positions. The gas was injected via holes in the pipe wall. The pressure was kept at 0.25 MPa (absolute) at the location of the active gas injection while the temperature was constant at 30°C 1K. This procedure exactly represents the evolution of the flow along the pipe, as it would be observed for an injection at a constant height position and a shifting of the measurement plane. The experiments were done for 48 combinations of air and water superficial velocities varying from 0.04 m/s to 1.6 m/s for water and 0.0025 m/s to 3.2 m/s for air. From the raw data time averaged data as: radial gas volume fraction profiles, bubble size distributions, radial volume fraction profiles decomposed according to the bubble size and the radial profiles of the gas velocity were calculated. Due to the combination of the new experimental procedure with the high spatial and temporal resolution of the wire-mesh sensor technology the data are have new quality especially regarding their consistency in the evolution with increasing L/D. This closes a gap for data suitable for the development and validation of closure models for two-phase flows and especially for models on bubble coalescence and break up.

Keywords: multiphase flow; bubbly flow; churn turbulent flow; annular flow; bubble size; pipe flow

  • International Journal of Thermal Sciences 49(2010), 664-674