CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

Changing boundary condition Ux after fluid reaches a specific distance

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   November 19, 2019, 05:23
Default Changing boundary condition Ux after fluid reaches a specific distance
Join Date: Jan 2019
Posts: 63
Rep Power: 6
mcfdma is on a distinguished road
Hello. I am working on filling the capillary with fluid.

The flow rate (Ux) is slow and the capillary is long which results in taking significant amount of time to fill the entire capillary.

Is there a way to speed up this process by initially setting the Ux to be high (higher than the value needed for the case) and once it reaches a particular distance in x coordinate, the Ux value is reduced automatically without me stopping the case and manually reducing the Ux and re-running it.

I have been looking at codedFixedValue but not sure.
Any help?
mcfdma is offline   Reply With Quote

Old   November 19, 2019, 10:03
Join Date: Nov 2011
Location: Germany
Posts: 91
Rep Power: 13
einstein_zee is on a distinguished road
Hi there,

you may find this one useful How to correctly show the result of #codeStream# internalField?
einstein_zee is offline   Reply With Quote

Old   November 21, 2019, 03:52
Join Date: Dec 2018
Location: Darmstadt, Germany
Posts: 87
Rep Power: 6
raumpolizei is on a distinguished road
I don't know your specific case but this sounds like this could be estimated by hand. With codedFixedValue, you are on the right track. Based on what you wrote there are a few other options you may want to try out:
  1. GroovyBC - check if swak4foam is available for your OF version. You could prescribe a ramp for the inflow velocity.
  2. Also, depending on your domain, you may want to have a look at funkysetfields (also a swak4foam utility).
  3. This wont solve you problem but you could use a coarse mesh and run the case until you are reaching the state of interest. Or a bit before if the case is turbulent in order to allow turbulence to evolve. Map it to the fine mesh and continue your simulations (mapFields).
  4. Write a bash script for the whole case, including the velocity change (use foamDictionary and similar commands).
Good luck!
raumpolizei is offline   Reply With Quote


capillary flow, interfoam

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
My radial inflow turbine Abo Anas CFX 27 May 11, 2018 01:44
Question about adaptive timestepping Guille1811 CFX 25 November 12, 2017 17:38
Low torque values on Screw Turbine Shaun Waters CFX 34 July 23, 2015 08:16
Question about heat transfer coefficient setting for CFX Anna Tian CFX 1 June 16, 2013 06:28
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 15:55

All times are GMT -4. The time now is 00:22.