[totopo]

Hello everyone. I am trying to write a UDF for the slip velocity in a multiphase mixture system using the macro DEFINE_VECTOR_ EXCHANGE_PROPERTY.
The formulation that I have depends on the gradient of the strain rate magnitude. As I understand it, I can retrieve the strain rate magnitude using C_STRAIN_RATE_MAG(c,t). My idea was loading said strain rate magnitude into a UDS and then getting the gradient using C_UDSI_G. I have unable to do so and gotten fatal errors in the process. I would appreciate any insight into how to go about accessing the gradient of the strain rate magnitude for use in the DEFINE_VECTOR_ EXCHANGE_PROPERTY macro.
Thanks!