Rob
Ansys Employee

You might want to start here https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v222/en/flu_udf/flu_udf_DPMDEFINE.html%23flu_udf_sec_define_dpm_erosion   The particle is the cause of the source/blockage which is then mapped onto the UDM.