volume force on dispersed phase only?

hi everyone

i am relatively new to comsol and ran into a perhaps simple problem:

i'm simulating a two-phase mixture model in the chemical engineering module. i want the dispersed solid phase to be influenced by a volume force from another physics model.

if i specify that force in the physics tab of my mixture subdomain, obviously the entire fluid is influenced by this force (same if i apply gravity). is it possible to specify that force so that only the dispersed phase is influenced and not the continuous phase?

any help would be greatly appreciated.

greetings
dave