Erosion modelling in slurry flow through pipelines
 

I have already explored the option to solve erosion model and also solved the erosion rate on a nozzle of 3.6mm inlet dia and 0.8 mm of outlet dia. Now i am working on a model that is a big container of inlet dia 250 mm and 31 mm but i am not getting the result though i am solving it with same procedure. I want to ask is there any changes required in erosion modelling procedure or the values that i am taking if the inlet and outlet size increases suddenly like in this case.
thanks