Capacitance wire mesh imaging of bubbly flows for offshore treatment applications


Capacitance wire mesh imaging of bubbly flows for offshore treatment applications

Assima, G. P.; Larachi, F.; Schleicher, E.; Schubert, M.

The impact of ship motion bubbly flow was emulated using as well simulator to expose flow structure changes emerging in bubble columns relevant to offshore floating applications. Roll, roll+pitch, yaw, heave and sway were implemented at various frequencies and changes in bubbly flow resulting from the imposed motions were monitored for the first time by means of a dual capacitance wire mesh sensor to measure local gas holdup and velocity. Visualizations of the two-phase flow revealed that roll, roll+pitch, and high-frequency sway were the most impactful in terms of bubble zigzag and swirl, and bubble-clustering and segregation due to vessel dynamic inclinations. As a consequence of the se motions, lateral migration of bubbles and their clustering enhanced liquid recirculation and local streamwise gas velocity. Compared to static vertical bubble column, bubbly flow pattern was barely altered by yaw and low-frequency sway except the heave displacements which tended to slow down the bubble rise.

Keywords: bubble column; wire mesh capacitance sensor; gas holdup; gas interstitial velocity; swell simulator; marine applications

Permalink: https://www.hzdr.de/publications/Publ-21635
Publ.-Id: 21635