I am currently researching the flow properties of organic materials, (plant residues) through a centrifugal fan, 

however, within the particle studies results section there is no material available that matches the properties of the materials i am studying. 

The particles i am dealing with are around 150-200mm in length and 5mm in diameter, so could be modelled as cylinder.

Is it possible to add custom materials with varying shapes and  physical properties to the particle study? 

Any assistance would be appreciated,

Thankyou