Simulate debris movement ?
 

Hello ,
There are 2 chambers which are connected through a pipe . 2 chambers are seperated by a sliding part in between . fluid flows from one chamber to other through pipe when the slider is moved , due to the sliding motion the wall wears .I want to simulate the movement of debris when the slider is moved .Please suggest a way of doing the simulation , also the softwares which are capable of doing it .
Thanks ,
Devaraj