Time-averaged velocity for transient flow using UDF or Data sampling

7sen · October 13, 2017, 20:34

Hello Everyone,

I'm conducting some research for my Master's project and I'm having some trouble figuring this out. I searched everywhere for a solution but I can't seem to find one.

I've only seen one reply but I can't access the UDF they provided (http://www.eureka.im/1104.html)

I'd really appreciate it if someone can help me. An example is this:

I iterated my case till timestep no. 200, saving files after every 10 timesteps. Now I want to see the average velocity for timesteps 50 to 120.

I tried looking at Data sampling, but I couldn't find a place where I can choose from timesteps 50 to 120; or any range of timesteps that is.

I would really appreciate any help.

Best Wishes,

HZ

2phase · October 18, 2017, 12:11

Hi HZ,

best way is to define your own monitor points and report files.
On the left hand side in "monitors" you can define your own statements/parameters/monitor points for surfaces or volumes like "mass weighted average of velocity @ inlet" similar things.

Then you can plot them like the residuals or check to write them to a file in your solution directory... if you have several variables you can create a report file and get them all into one file with values for every time step / iteration and then process them in Matlab or whatever.

Of course you need to define this before running the simulation, I do not know if there is an option for getting this data after a calculation similar to what you just tried.

Good luck trying.

Martin

October 13, 2017, 20:34	Time-averaged velocity for transient flow using UDF or Data sampling	#1
7sen New Member Join Date: Oct 2017 Posts: 2 Rep Power: 0	Hello Everyone, I'm conducting some research for my Master's project and I'm having some trouble figuring this out. I searched everywhere for a solution but I can't seem to find one. I've only seen one reply but I can't access the UDF they provided (http://www.eureka.im/1104.html) I'd really appreciate it if someone can help me. An example is this: I iterated my case till timestep no. 200, saving files after every 10 timesteps. Now I want to see the average velocity for timesteps 50 to 120. I tried looking at Data sampling, but I couldn't find a place where I can choose from timesteps 50 to 120; or any range of timesteps that is. I would really appreciate any help. Best Wishes, HZ

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October 18, 2017, 12:11		#2
2phase New Member Martin Join Date: Apr 2017 Location: Germany Posts: 26 Rep Power: 10	Hi HZ, best way is to define your own monitor points and report files. On the left hand side in "monitors" you can define your own statements/parameters/monitor points for surfaces or volumes like "mass weighted average of velocity @ inlet" similar things. Then you can plot them like the residuals or check to write them to a file in your solution directory... if you have several variables you can create a report file and get them all into one file with values for every time step / iteration and then process them in Matlab or whatever. Of course you need to define this before running the simulation, I do not know if there is an option for getting this data after a calculation similar to what you just tried. Good luck trying. Martin