"parcel" button in fluent discrete phase model
 

hi everyone!
I am learning fluent DPM(discrete phase model) operations and modeling particle deposition in ventilating duct, but i ran into a problem recently:
“parcel” button is grey in Set Injection Properties. I want to know how to activate “parcel” button. The turbulent model i use is RSM(reynolds stress model). The setting figure is as follows.

https://github.com/Enjoyer007/markdo...1.png?raw=true

https://github.com/Enjoyer007/markdo...2.png?raw=true