How to modify the stress tensor of momentum eqns.
 

The FLUENT can only handle newtonian fluid and some non-newtonian. It is the stress tensor that makes the model different. In my case, the expression of the stree tensor is different and need using UDF to add in. Please tell me how to change the stress tensor in the momentum equations using UDF. Many Thanks

Hi, Jason, i wonder if you have got any idea about how to change the stress tensor with the UDF. I am simulating one non-newtonian fluid and need a new model to deal with the stress tensor in the momentum equation. Thanks. Best Regards.Li