Changing devolatilisation Arrhenius parameters via UDF?

Baum · December 2, 2019, 09:09

Hi all,

I am currently wondering about how I can change the Arrhenius parameters of the devolatilisation of a particle based on the particle diameter. I don't really want to re-write the whole devolatilisation law with mass and energy balances, since that seems like overkill.

The pseudo-code looks like this:
/******* UDF that models custom Arrhenius parameters for each particle **************/

#include "udf.h"
DEFINE_DPM_LAW(variable_Arrhenius, p, ci){
if (0 < P_DIAM(p) < 100)
A = 1;
E = 100;
else if ( 100 < P_DIAM(p) < 500)
A = 2;
E = 200;
else
A = 3;
E = 300;
VaporizationLaw(p);
}

But I can not seem to find a way to edit A and E?

Any help would be appreciated.

Cheers!

AlexanderZ · December 2, 2019, 20:17

share your case, I'll try to find something

Baum · December 3, 2019, 11:29

Hey Alexander, thanks for the quick reply. I am not able to share the real case, but in general it's just a simple tube with a particle injection at one end. I have a representative simplified case at hand, however I seem not to be able to upload it here due to file restrictions. The geometry and injections are irrelevant though, and the problem can be found in any combustion case.

AlexanderZ · December 4, 2019, 23:55

I dont know how to set up this problem correctly. No experience, cant help you without case

December 2, 2019, 09:09	Changing devolatilisation Arrhenius parameters via UDF?	#1
Baum New Member Join Date: Dec 2019 Posts: 29 Rep Power: 7	Hi all, I am currently wondering about how I can change the Arrhenius parameters of the devolatilisation of a particle based on the particle diameter. I don't really want to re-write the whole devolatilisation law with mass and energy balances, since that seems like overkill. The pseudo-code looks like this: /***** UDF that models custom Arrhenius parameters for each particle ************/ #include "udf.h" DEFINE_DPM_LAW(variable_Arrhenius, p, ci){ if (0 < P_DIAM(p) < 100) A = 1; E = 100; else if ( 100 < P_DIAM(p) < 500) A = 2; E = 200; else A = 3; E = 300; VaporizationLaw(p); } But I can not seem to find a way to edit A and E? Any help would be appreciated. Cheers!

December 2, 2019, 20:17		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	share your case, I'll try to find something __________________ best regards ****************************** press LIKE if this message was helpful

December 4, 2019, 23:55		#4
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	I dont know how to set up this problem correctly. No experience, cant help you without case __________________ best regards ****************************** press LIKE if this message was helpful

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December 3, 2019, 11:29		#3
Baum New Member Join Date: Dec 2019 Posts: 29 Rep Power: 7	Hey Alexander, thanks for the quick reply. I am not able to share the real case, but in general it's just a simple tube with a particle injection at one end. I have a representative simplified case at hand, however I seem not to be able to upload it here due to file restrictions. The geometry and injections are irrelevant though, and the problem can be found in any combustion case.