How to access species index for a particular specie in the UDF based on specie name


To write a generic udf that does not depend on the order in which species are specified in the mixture definition, it is needed to access the species index, i by passing the specie name as argument. How to do that in the UDF?
There are two ways of doing this in Fluent UDF.
1. To use mixture_specie_index macro. A snippet of code pasted below will get species index for specie co2
Material *m = THREAD_MATERIAL(t);
char *name = "co2";
int i;
i = mixture_specie_index(m,name);

2. Alternately, following macro can also be used
i = SV_SpeciesIndex("co2");

With option 2, if co2 is not present in the defined meixture, Fluent will give seg violation and will cause error. With option 2, it will return -1 if co2 is not defined as part of mixture species and hence appropriate care can be taken in the udf coding to give relevent error messages etc.





Show Form
No comments yet. Be the first to add a comment!