When I tried to compile a udf in which solid species mass fraction X_s used, I got a mistake as follows:

Then I checked `fldvar_mod.f`

out and found that X_s was defined here a three-dimensional allocatable array, I think I’ve missed a parameter here because I just offered `NP`

and species’s name, a two-dimensional array, so what is the parameter I’ve missed?

`X_s`

is the solid species mass fraction for TFM. First index is the computational cell, second index is the solids phase, third index is the species.

If you want to use DEM, then the array is `DES_X_s`

. The first index is the particle and the second index is the species.

I appreciate your detailing explanation!