UDF - Write data into file at the end of every time-step

rookiecfd · April 13, 2017, 09:45

Hello everyone,

I need to write a UDF to be executed with a transient simulation. I have specified the number of iterations to be carried out per time-step. I need to make a UDF that will write some data into a file at the end of each time-step. I don't want to see this at every iteration per time-step. Say, I specify 20 iterations per time-step. Then I want to have the data written at the end of 20th iteration or at the point where convergence is achieved for a time-step. Could someone tell me how can this be achieved? Thanks in advance!

Boh · April 13, 2017, 10:28

The EXECUTE_AT_END macro is executed at the end of each time step of a transient model...so if you write into your file inside this macro it will contain only the values at the end of each time step.

rookiecfd · April 13, 2017, 10:54

Quote:

Originally Posted by Boh

The EXECUTE_AT_END macro is executed at the end of each time step of a transient model...so if you write into your file inside this macro it will contain only the values at the end of each time step.

Thank you Boh. Let me try that out.

rookiecfd · April 13, 2017, 14:14

Hi,

unfortunately, that did not work out. It is still printing values at every iteration per time-step. Could someone help me out on this?

qorka · April 14, 2017, 03:53

Quote:

Originally Posted by rookiecfd

Hi,

unfortunately, that did not work out. It is still printing values at every iteration per time-step. Could someone help me out on this?

If you solve in transient, EXECUTE_AT_END is called at the end of time step (it works good by me)
In static analys it is called at the end of iteration

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rookiecfd · April 14, 2017, 08:05

Hi Boh and qorka,

Thanks for the reply. So that means it has to do something with my code.
I wrote a UDF to calculate the point of slowest blending in a mixing tank based on mass fraction of species. I tried running it on a Linux system with one node (16 cores) but I did not make it compatible for parallel processing. Am getting weird results. Have to go back and check where I made the mistake.

qianquan · April 14, 2017, 20:13

let me try

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rookiecfd · April 17, 2017, 11:21

..........................................

April 13, 2017, 09:45	UDF - Write data into file at the end of every time-step	#1
rookiecfd New Member Join Date: Apr 2017 Posts: 7 Rep Power: 9	Hello everyone, I need to write a UDF to be executed with a transient simulation. I have specified the number of iterations to be carried out per time-step. I need to make a UDF that will write some data into a file at the end of each time-step. I don't want to see this at every iteration per time-step. Say, I specify 20 iterations per time-step. Then I want to have the data written at the end of 20th iteration or at the point where convergence is achieved for a time-step. Could someone tell me how can this be achieved? Thanks in advance!

April 17, 2017, 11:21		#8
rookiecfd New Member Join Date: Apr 2017 Posts: 7 Rep Power: 9	.......................................... Last edited by rookiecfd; May 3, 2017 at 14:55.

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April 13, 2017, 10:28		#2
Boh Member Join Date: Sep 2016 Posts: 33 Rep Power: 10	The EXECUTE_AT_END macro is executed at the end of each time step of a transient model...so if you write into your file inside this macro it will contain only the values at the end of each time step.

April 13, 2017, 14:14		#4
rookiecfd New Member Join Date: Apr 2017 Posts: 7 Rep Power: 9	Hi, unfortunately, that did not work out. It is still printing values at every iteration per time-step. Could someone help me out on this?

April 14, 2017, 08:05		#6
rookiecfd New Member Join Date: Apr 2017 Posts: 7 Rep Power: 9	Hi Boh and qorka, Thanks for the reply. So that means it has to do something with my code. I wrote a UDF to calculate the point of slowest blending in a mixing tank based on mass fraction of species. I tried running it on a Linux system with one node (16 cores) but I did not make it compatible for parallel processing. Am getting weird results. Have to go back and check where I made the mistake.

April 14, 2017, 20:13		#7
qianquan New Member 钱权 Join Date: Mar 2017 Posts: 5 Rep Power: 9	let me try Sent from my iPhone using CFD Online Forum mobile app