UDRGM problem with implementation

natalia_ · May 15, 2019, 11:18

Hello everyone,

currently, I'm struggling with user defined real gas model of an ideal gas. When I compile the template code (ideal gas) I receive warnings:

When I turn on the real-gas and start the calculation a have nan values of residuals. I don't really have a clue, what is the reason for this error. I'm using a template code provided by Fluent in the user's guide for Fluent v.193 (https://ansyshelp.ansys.com/account/...gas_udrgm.html). So I assume that there is no problem with the structure of the code, but with the compilation or Fluent interpretation.

Does anyone know what might be a problem?

If anybody could help, that would be much appreciated!

AlexanderZ · May 15, 2019, 23:35

Was your code successfully compiled?

best regards

seyf97 · May 15, 2020, 16:25

Hi, I have the same problem. I found out that this is caused because the given code in the user's guide is for an older version of Fluent, but I couldn't find any recent version of the code.

vinerm · May 15, 2020, 17:50

Yes, this is because the arguments for the functions and the functions themselves have changed over last few versions. So, you need to ensure correct arguments. There is an old UDRGM code given in examples. It has been there for last decade or so but has not been updated. If you are using that code, then update the arguments to the functions. The code will work, except that the arguments need to be properly given.

seyf97 · May 15, 2020, 18:02

Thank you so much for your swift reply. I have solved the problem by using the example code given in the program's user guide.

May 15, 2019, 11:18	UDRGM problem with implementation	#1
natalia_ New Member Natalia Join Date: May 2019 Posts: 2 Rep Power: 0	Hello everyone, currently, I'm struggling with user defined real gas model of an ideal gas. When I compile the template code (ideal gas) I receive warnings: When I turn on the real-gas and start the calculation a have nan values of residuals. I don't really have a clue, what is the reason for this error. I'm using a template code provided by Fluent in the user's guide for Fluent v.193 (https://ansyshelp.ansys.com/account/...gas_udrgm.html). So I assume that there is no problem with the structure of the code, but with the compilation or Fluent interpretation. Does anyone know what might be a problem? If anybody could help, that would be much appreciated!

May 15, 2020, 17:50	Udrgm	#4
vinerm Senior Member Vinerm Join Date: Jun 2009 Location: Nederland Posts: 2,946 Blog Entries: 1 Rep Power: 36	Yes, this is because the arguments for the functions and the functions themselves have changed over last few versions. So, you need to ensure correct arguments. There is an old UDRGM code given in examples. It has been there for last decade or so but has not been updated. If you are using that code, then update the arguments to the functions. The code will work, except that the arguments need to be properly given. __________________ Regards, Vinerm PM to be used if and only if you do not want something to be shared publicly. PM is considered to be of the least priority.

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May 15, 2019, 23:35		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	Was your code successfully compiled? best regards

May 15, 2020, 16:25		#3
seyf97 New Member seyf Join Date: May 2020 Posts: 5 Rep Power: 6	Hi, I have the same problem. I found out that this is caused because the given code in the user's guide is for an older version of Fluent, but I couldn't find any recent version of the code.

May 15, 2020, 18:02		#5
seyf97 New Member seyf Join Date: May 2020 Posts: 5 Rep Power: 6	Thank you so much for your swift reply. I have solved the problem by using the example code given in the program's user guide.