Implementation of Breakup and Coalescence Models into CFD of Bubble Column Flows Peng Chen and M.P. Duduković CHEMICAL REACTION ENGINEERING LABORATORY Chemical Reaction Engineering Laboratory (CREL) Department of Chemical Engineering Washington University St. Louis, MO 63130, USA CREL Annual Meeting November 15, 2001 G G L

G G L CHEMICAL REACTION ENGINEERING LABORATORY I need to use CFD models to predict the performance of a bubble column Only Eulerian model seems feasible for churn turbulent flow regime Different size bubbles have different magnitude of interaction with liquid “Mean” bubble size is the simplest and easiest assumption

G G L CHEMICAL REACTION ENGINEERING LABORATORY 2 mm?Hours or Days of simulation …… Results not good. I need to input a “mean” bubble size (diameter) …… 12 mm?Hours or Days of simulation …… What is the MAGIC number?!!! Results is good! 20 mm?Hours or Days of simulation …… Results not good. 5 mm?Hours or Days of simulation …… Results not good. ………………..

G G L CHEMICAL REACTION ENGINEERING LABORATORY How about a different column operate under different operation condition? We need to predict bubble size locally! How? To incorporate bubble population balance equation with breakup and coalescence model into CFD. How?

Next presentation