f = block.proppant.grainsize.factor
block.proppant.grainsize.factor = f

Get/set the proppant grain size multiplication factor. If greater than 0, proppant flow will cease through nodes in which the aperture is less than this factor times the proppant grain size. The permeability of the associated flow zone is the proppant blocked permeability factor times the inherent permeability.

Returns:f - multiplication factor
Accepts:f - multiplication factor