UDF reading species data of pdf simulations

Jamiro

Hi CFD friends!

I'm implementing a UDF for NOx calculations on a pdf solution: I'm using the built-in DEFINE_SOURCE function to add a customized reaction rate to NO transport equation. To do this my UDF must read the values of some mass fraction species (variables C_YI(c,t,i)), already calculated in the main simulation. But running it, I don't succeed in performing one iteration at all because an error "SEGMENTATION VIOLATION..." appears. I guess it is because in pdf calculations only 'fmean' and 'fvar' are variable solutions, while species mass fractions are calculated in post-processing by means of look-up tables. In fact, running the same UDF on a finite-chemistry solution no problem was encountered.

Anyone may clarify that and purpose a solution for pdf species data to be read (or pointed) by this kind of UDF for NOx?

I'm thanking you a lot for any suggestion.

Jamiro