CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > CFX

How to define the inlet using an Interpolation Functions or Data sheet?

Register Blogs Community New Posts Updated Threads Search

Like Tree3Likes
  • 1 Post By evcelica
  • 1 Post By AtoHM
  • 1 Post By IronLyon

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 15, 2019, 11:01
Default How to define the inlet using an Interpolation Functions or Data sheet?
  #1
Member
 
Join Date: Feb 2019
Posts: 30
Rep Power: 7
IronLyon is on a distinguished road
Hello , I want to use the mass flow rate as the inlet, before I just defined it as constant value or write in the expression and use a function. However, the function what I used is just an approximate fuction calculated from my experiment date, that was not realistic. So now I just want to input the time point and the correspond mass flow rate, like create an Excel data and then use choose the ''Tool'' - ''Initialize Profile Date'' to upload the excel data (is that true, I don't have experience)?
I will try that and want to know, what is the right form to write in the excel? Like:
Time point [s] mass flow rate [kg s-1]
0 0
0.5 1.25
1 2.1
1.5 3.2
2 3.9
...
I tried, but it said ''Invalid format''. How could I input the data in a right way? Thank you!
IronLyon is offline   Reply With Quote

Old   May 15, 2019, 16:23
Default
  #2
Senior Member
 
Erik
Join Date: Feb 2011
Location: Earth (Land portion)
Posts: 1,167
Rep Power: 23
evcelica is on a distinguished road
Just create a user function in cfx-pre.

You can either type in the data points, or import a text file with just 2 columns of data (numbers only). Define the units of the independent variable time [s] and result variable [kg/s]. Then use this function as your inlet mass flow condition: MyFunctionName(t)
3nhu1 likes this.
evcelica is offline   Reply With Quote

Old   May 16, 2019, 02:58
Default
  #3
Senior Member
 
M
Join Date: Dec 2017
Posts: 642
Rep Power: 12
AtoHM is on a distinguished road
https://www.sharcnet.ca/Software/Ans....html#i1310599


I attached an example with variable mass flow. Once imported into pre you can reference the profile by its expression as MassFlowRate.Mass Flow Rate(Time) within the boundary setup.
Attached Images
File Type: png profile.png (7.0 KB, 90 views)
3nhu1 likes this.
AtoHM is offline   Reply With Quote

Old   May 17, 2019, 05:12
Default
  #4
Member
 
Join Date: Feb 2019
Posts: 30
Rep Power: 7
IronLyon is on a distinguished road
Quote:
Originally Posted by evcelica View Post
Just create a user function in cfx-pre.

You can either type in the data points, or import a text file with just 2 columns of data (numbers only). Define the units of the independent variable time [s] and result variable [kg/s]. Then use this function as your inlet mass flow condition: MyFunctionName(t)

Thank you!
IronLyon is offline   Reply With Quote

Old   May 17, 2019, 05:20
Default
  #5
Member
 
Join Date: Feb 2019
Posts: 30
Rep Power: 7
IronLyon is on a distinguished road
Quote:
Originally Posted by AtoHM View Post
https://www.sharcnet.ca/Software/Ans....html#i1310599


I attached an example with variable mass flow. Once imported into pre you can reference the profile by its expression as MassFlowRate.Mass Flow Rate(Time) within the boundary setup.

Thank you!
I succeed in using txt to write the fuction. The pic is shown as flowing:
1111111.PNG
And then in the inlet using the user function, after loading it likes
MFR.Mass Flow Rate(), then the only thing needs to be done is add the Time like MFR.Mass Flow Rate(Time).
3nhu1 likes this.
IronLyon is offline   Reply With Quote

Old   May 17, 2019, 05:27
Default
  #6
Member
 
Join Date: Feb 2019
Posts: 30
Rep Power: 7
IronLyon is on a distinguished road
[solved and further question delete]
IronLyon is offline   Reply With Quote

Old   November 26, 2023, 18:00
Default
  #7
New Member
 
Join Date: Apr 2022
Posts: 25
Rep Power: 4
3nhu1 is on a distinguished road
Quote:
Originally Posted by IronLyon View Post
Thank you!
I succeed in using txt to write the fuction. The pic is shown as flowing:
Attachment 70000
And then in the inlet using the user function, after loading it likes
MFR.Mass Flow Rate(), then the only thing needs to be done is add the Time like MFR.Mass Flow Rate(Time).
Many thanks- this helped me
3nhu1 is offline   Reply With Quote

Reply

Tags
data profile, initialize profile date, inlet, transient


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
CFD by anderson, chp 10.... supersonic flow over flat plate varunjain89 Main CFD Forum 18 May 11, 2018 07:31
How to assign the inlet B.C using a bunch of data set for an unsteady problem? ali8500 CFX 3 March 28, 2012 18:41
how to provide accurate inlet boundary condition from experimental data? swe704 FLUENT 0 September 29, 2009 04:01
REAL GAS UDF brian FLUENT 6 September 11, 2006 08:23
Free surface boudary conditions with SOLA-VOF Fan Main CFD Forum 10 September 9, 2006 12:24


All times are GMT -4. The time now is 09:45.