Pdf_XY and Pdf_Yi

  • Last Post 24 April 2020
  • Topic Is Solved
Jeroen posted this 23 April 2020



I am trying to get the species mass and molar fractions for my continuous gas phase into a UDF for DEFINE_DPM_HEAT_MASS(). According to the manual, this can be done by using the following.

Pdf_Yi(c, t, n) or Pdf_XY(c,t,x,y)

In order to use these expressions "pdf_props.h" must be included. Hooking the UDF causes no issues, however upon running my model the simulation crashes when reaching the DPM Iteration. More specifically: it crashes because of these functions.

I am using Fluent version 19.3. Is there any other way to get these fractions for a species transport model? Or how do i resolve this issue?


Kind regards,


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abenhadj posted this 23 April 2020

Are you working with pdf based combustion model or just using species model?

Best regards, Amine

Jeroen posted this 23 April 2020

Im am just using a species model, no combustion involved here

rwoolhou posted this 23 April 2020

Then have a look for the species macros, the pdf ones you're using relate to a combustion model. 

Jeroen posted this 24 April 2020

I got it to work by using c->yi[ns]

previously this did not work because there was an error in my cphase_state_t variable, it should have been:

cphase_state_t *c = &(tp->cphase[0]);


Thanks for your help

abenhadj posted this 24 April 2020

The example in the manual does cover it.

Best regards, Amine