Reply To: In the fluentDPM model, udf is used to calculate the gas density of the particle

[Rob]

That macro is defined here, https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v242/en/flu_udf/flu_udf_DataAccessMacros.html%23flu_udf_sec_dpm_macros and isn't density. Particle density is set in the materials panel, but TP_RHO(tp) is available.