scalar transport model
 

hello

I am trying to do a species model in ansys fluent 14.0. I am using k-eplison model.
I have run the model in first order and got stable residuals
then second order and I get turbulent viscosity ratio 1e5 in 5 cells.
then I put it in transient with the species model and i was expecting a cumulative curve (f-curve) up to 1. however i get a curve like the one in the attached photo. Any ideas for the cause/ solution to this?

Thanks