How to measure gas holdup in bubble column
 

Hello sir
I am working on a project where I need to measure the gas holdup in a three-phase bubble column with varying superficial gas velocity and also with different solid concentration by volume.
I am using population balance coupled with the Eulerian multiphase model. The population balance approach is used to solve for bubble flow and
size distribution in a 3D bubble column for a population of ten different bubble sizes.

please help me with the following:
1. How to define slurry phase with different solid concentration?
2. How to measure gas holdup?

Please suggest me, solver settings
thank you in advance:)
contact: sunilsah2011@gmail.com