Accessing net reaction rates of each species in DEFINE_ADJUST?

Baum · August 8, 2022, 07:54

Hi all, the title pretty much says it all: How do I access the value of the current reaction rate for a species in each cell within an ADJUST UDF? I don't want to change the value, just read it. Is there a way, for example, to access the pointer *rr like you can in other UDFs (DEFINE_NET_REACTION_RATE etc.)?

Thanks!

Baum

AlexanderZ · August 10, 2022, 00:58

Look for Ansys Fluent Customization manual -> DEFINE_DPM_INJECTION_INIT -> example
that could be useful

to get cell and thread you probably need a loop over particles, could be done like this:

Code:

Injection *I;
Particle *p;

I = Get_dpm_injections();
loop(p, I->p)
{
code
}

I think it could be done inside ADJUST UDF

Baum · August 11, 2022, 03:23

Hi Alexander, thanks for the reply. I looked at the UDF manual and could not really find anything about accessing the reaction rate there. It seems like they calculate their own reaction rate based on temperature and concentration, but they don't access the current value stored in the cell.

Also, I don't really want to use a DPM injection just to find this value, so I think an ADJUST UDF is definitely preferred.

Maybe another way to formulate this question could be: Can I just write "Reaction Rate *rr" or something similar somewhere in the ADJUST UDF and access that structure?

August 8, 2022, 07:54	Accessing net reaction rates of each species in DEFINE_ADJUST?	#1
Baum New Member Join Date: Dec 2019 Posts: 29 Rep Power: 6	Hi all, the title pretty much says it all: How do I access the value of the current reaction rate for a species in each cell within an ADJUST UDF? I don't want to change the value, just read it. Is there a way, for example, to access the pointer *rr like you can in other UDFs (DEFINE_NET_REACTION_RATE etc.)? Thanks! Baum

August 10, 2022, 00:58		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	Look for Ansys Fluent Customization manual -> DEFINE_DPM_INJECTION_INIT -> example that could be useful to get cell and thread you probably need a loop over particles, could be done like this: Code: Injection I; Particle p; I = Get_dpm_injections(); loop(p, I->p) { code } I think it could be done inside ADJUST UDF __________________ best regards ****************************** press LIKE if this message was helpful

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Which macro gives the net reaction rate of species in a multistep chemical reaction	Van9527	Fluent UDF and Scheme Programming	0	March 12, 2021 03:36
Reaction Species transport and Population Balance	abgoel363	Fluent Multiphase	0	January 20, 2020 07:08
Modelling species transport and implementing reaction rates	res	FLUENT	0	May 11, 2017 10:29
Segmentation fault in running alternateSteadyReactingFoam,why?	NewKid	OpenFOAM	18	January 20, 2011 16:55
chemical reaction - decompostition	La S. Hyuck	CFX	1	May 23, 2001 00:07

August 11, 2022, 03:23		#3
Baum New Member Join Date: Dec 2019 Posts: 29 Rep Power: 6	Hi Alexander, thanks for the reply. I looked at the UDF manual and could not really find anything about accessing the reaction rate there. It seems like they calculate their own reaction rate based on temperature and concentration, but they don't access the current value stored in the cell. Also, I don't really want to use a DPM injection just to find this value, so I think an ADJUST UDF is definitely preferred. Maybe another way to formulate this question could be: Can I just write "Reaction Rate *rr" or something similar somewhere in the ADJUST UDF and access that structure?