I see the correction factor in Beetstra’s article “Numerical study of segregation using a new drag force correlation for polydisperse systems derived from lattice-Boltzmann simulations” as follows:
But there is an extra multiplication of 1/yi^2 in mfix, and I’m not sure why that is?
Perhaps this comment explains it? Directly above the code you quoted:
! see erratum by Beetstra et al. (2007) : the correction factor differs
! for model A versus model B.
! application of the correction factor for model A is found from
! the correction factor for model B and neglects the Y_i**3 term
And in init_namelist.f:
! For PCF details see:
!
!
! - Van der Hoef MA, Beetstra R, Kuipers JAM. (2005)
! Journal of Fluid Mechanics.528:233-254.
! - Beetstra, R., van der Hoef, M. A., Kuipers, J.A.M. (2007).
! AIChE Journal, 53:489-501.
! - Erratum (2007), AIChE Journal, Volume 53:3020
I looked at these articles, including those after Beetstra made the corrections.
It indicates that only yi needs to be multiplied by the drag force. but then in mfix it is in addition to yi^2.
@jmusser @galvinj Any comment on the above? I see your names in the git logs for model/drag_gs.f (10 years ago).
@jmusser @galvinj Hello Dr. Janine and Dr. jmusser. I’ve gone through a lot of literature and never understood why polydisperse systems are fixed like this in MFIX. It is very desirable to confirm the correct form of the correction factor, which is very important for the correction of polydisperse particles. I am very eager to hear back from you.