Difference Between UDF and Expressions in Thermal Comfort Evaluation?

danisnug · April 29, 2019, 00:37

Good day,

I am conducting evaluation of cabin thermal comfort inside passenger bus using PMV equation from ISO 7730 standard. At first I'm gonna use UDF but a friend of mine told me that I can use expressions inside the Fluent post-processing program. However, I'm not sure what are the differences between those two in evaluating thermal comfort. Is it okay if I use expressions instead of UDF? What are the differences between those two?

AlexanderZ · April 29, 2019, 04:03

Fluent post-processing program means post processing
UDF may influence (or may not) solution. If your goal is a combination of variables, which are calculated by default -> you may use expression instead of UDF

best regards

danisnug · May 11, 2019, 00:05

Dear AlexanderZ, thank you for the explanation

Aven.farhan · March 27, 2020, 16:13

Hi..

Actually, I too need to work on the similar analysis, (thermal comfort). I got one extension(of thermal comfort) from Ansys website, unfortunately that isn't working out. Can you suggest me about the expression thing.

I'm new to Ansys fluent, unable to catch up..

Any help, I will be really thankful.

Thank you

Cheers Mohammed.

shadymody · January 4, 2023, 08:00

Quote:

Originally Posted by Aven.farhan

Hi..

Actually, I too need to work on the similar analysis, (thermal comfort). I got one extension(of thermal comfort) from Ansys website, unfortunately that isn't working out. Can you suggest me about the expression thing.

I'm new to Ansys fluent, unable to catch up..

Any help, I will be really thankful.

Thank you

Cheers Mohammed.

Dear, what is the name of the extension you found? and did you find a way to implement thermal comfort calculation?

Aven.farhan · January 4, 2023, 08:35

Hi.

The extension doesn't work.
I finally created custom functions. I investigated PMV, PPD, Pd, Age of Air. All of these using custom functions.
Thanks
Mohammad
Email - aven.farhan@gmail.com

shadymody · January 4, 2023, 09:30

Quote:

Originally Posted by Aven.farhan

Hi.

The extension doesn't work.
I finally created custom functions. I investigated PMV, PPD, Pd, Age of Air. All of these using custom functions.
Thanks
Mohammad
Email - aven.farhan@gmail.com

can you please help me on these

danghuy_1995 · April 11, 2023, 05:59

Quote:

Originally Posted by Aven.farhan

Hi.

The extension doesn't work.
I finally created custom functions. I investigated PMV, PPD, Pd, Age of Air. All of these using custom functions.
Thanks
Mohammad
Email - aven.farhan@gmail.com

Could you please help me on this thing? I have a research of evaluating PMV of a room on Ansys. I sent you an email asking for help.
ldhuy.simeon@gmail.com
Thank you.

April 29, 2019, 00:37	Difference Between UDF and Expressions in Thermal Comfort Evaluation?	#1
danisnug New Member Join Date: Jan 2019 Location: Jakarta, Indonesia Posts: 7 Rep Power: 7	Good day, I am conducting evaluation of cabin thermal comfort inside passenger bus using PMV equation from ISO 7730 standard. At first I'm gonna use UDF but a friend of mine told me that I can use expressions inside the Fluent post-processing program. However, I'm not sure what are the differences between those two in evaluating thermal comfort. Is it okay if I use expressions instead of UDF? What are the differences between those two?

April 29, 2019, 04:03		#2
AlexanderZ Senior Member Alexander Join Date: Apr 2013 Posts: 2,363 Rep Power: 34	Fluent post-processing program means post processing UDF may influence (or may not) solution. If your goal is a combination of variables, which are calculated by default -> you may use expression instead of UDF best regards

May 11, 2019, 00:05		#3
danisnug New Member Join Date: Jan 2019 Location: Jakarta, Indonesia Posts: 7 Rep Power: 7	Dear AlexanderZ, thank you for the explanation

March 27, 2020, 16:13		#4
Aven.farhan New Member Mohammed Khan Join Date: Jan 2020 Posts: 4 Rep Power: 6	Hi.. Actually, I too need to work on the similar analysis, (thermal comfort). I got one extension(of thermal comfort) from Ansys website, unfortunately that isn't working out. Can you suggest me about the expression thing. I'm new to Ansys fluent, unable to catch up.. Any help, I will be really thankful. Thank you Cheers Mohammed.

January 4, 2023, 08:35		#6
Aven.farhan New Member Mohammed Khan Join Date: Jan 2020 Posts: 4 Rep Power: 6	Hi. The extension doesn't work. I finally created custom functions. I investigated PMV, PPD, Pd, Age of Air. All of these using custom functions. Thanks Mohammad Email - aven.farhan@gmail.com