Hi everybody, I have to write a c code for the phase distribution in a bio reactor. So far I have the Navier-Stokes for pressure and velocity field. But what can calculate my phase distribution? I would be delighted for any suggestions. Thanks in advance, Stefan

Would you describe more detail about your phase distribution? My research area is multi-phase fluid flow, so I may have interest in your field.

What are governing equations for the phase distribution in a bio reactor?

Junseok Kim

Hello Mr. J. Kim,

thanks for your answer.

The bio reactor is filled with water. From holes the bottom come air bubbles and also some small solid particles with a diameter of some millimeters exist in the reactor. The reactor is a cylinder of 40cm in diameter and 5m in height. I transformed the Navier-Stokes equations to cylinder coordinates and redused it to a two dimensional form. I planned to let the continuity equation approximate a unit pressure field. This field I want to use in the momentum balance equations of each phase to calculate the velocities in an inner loop. Each equation needs a factor (between 0 and 1), which determines the volume fraction of the phase in the computational cell.

I guess, in my plan an outer loop is missing, which calculates these volume fractions and I have no idea of the equation, which can handle this problem.

Further I want to discretize the equations using finite volume differences, but I am still fighting with the integral law of Gauss to transform the volume integral into a surface intagral, because I never did a disretization in cylinder coordinates.

Thanks for thinking in my problem.

Regards,

Stefan