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-   -   Field function cannot be evaluated on region (http://www.cfd-online.com/Forums/star-ccm/87691-field-function-cannot-evaluated-region.html)

pauloabeck April 26, 2011 16:48

Field function cannot be evaluated on region
 
Hello All,

I'm trying to implement a user field function which is supposed to return the viscosity of a non-Newtonian fluid given the strain rate magnitude and other threshold parameters. I'm aware of the solver parameter "Temporary Storage Retained" which is set to true.

When trying to run the simulation, I'm receiving the message "Field function "SMD Viscosity" cannot be evaluated on region cell-2", where "SMD Viscosity" and "cell-2" are particular to my simulation.

Has someone faced this issue?

Thank you all,

abdul099 April 28, 2011 17:33

There's an error in the definition of the field function "SMD Viscosity".
Check whether all field functions referenced in "SMD Viscosity" are existing, no mistypings occured and you have put in the right names.

pauloabeck April 28, 2011 18:40

Thank you Abdul099. I've found the problem to be a variable name ill defined. The correct function definition, as a sample to others in need of help, looks like the following one:

($Iteration<1) ? $eta0 : (1-exp((-$eta0*$StrainRate)/$tau0))*(($tau0/$StrainRate)+$KConsistency*pow($StrainRate,$nBehav ior-1))+$etaInf*(1-exp(-$etaInf/($KConsistency*pow($StrainRate,$nBehavior-1))))

The $StrainRate variable is available only if the "Temporary Storage Retained" solver property is set to true. $StrainRate is the modulus of the mean strain rate tensor (Eq. 450 from the User's Manual).


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