CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Community Contributions

[waves2Foam] INLET relaxation boundary interface diffusion during irregular sea state

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 2, 2020, 11:58
Default INLET relaxation boundary interface diffusion during irregular sea state
  #1
New Member
 
Marc Batlle
Join Date: Mar 2017
Posts: 8
Rep Power: 5
Marc Batlle is on a distinguished road
Good afternoon,

These days I have been understanding and testing different features of the application waves2Foam with OF-v1912. My purpose is to reproduce different irregular sea states.

I created my own script as an input for the wavesProperties, similarly as the function "setWaveParameters". The irregular case is calibrated using a JONSWAP spectrum, with; Hs= 1m, Tp= 9s, peak enhancement=3.3 and a random phase.

The thing is, the free surface elevation seems to be well reproduced inside the relaxation zone but some kind of "dissipation" occurs at the boundary between the relaxation zone and the computation region. Lowering the whole wave heights and thus giving a very low energy spectrum within the computational zone.

I tested different lengths for the wave INLET region without any improvements, among other tests.

I attach one of my cases, where hopefully an experienced eye can find if this situation is due to a wrong case setup.

Thanks foamers,

Marc
Attached Files
File Type: gz CASE.tar.gz (18.8 KB, 3 views)
Marc Batlle is offline   Reply With Quote

Old   June 3, 2020, 07:05
Default
  #2
ngj
Senior Member
 
Niels Gjoel Jacobsen
Join Date: Mar 2009
Location: Deltares, Delft, The Netherlands
Posts: 1,864
Rep Power: 33
ngj will become famous soon enoughngj will become famous soon enough
Hi Marc,

Please read this post on giving sufficient information:

Guide: How to ask a question on the forums

For instance, you do not provide information on the grid and resolution, so it is very likely that the dissipation that you observe it due to too large cells. Also, you do not show an example of the claimed dissipation, which would also be useeful.

Kind regards

Niels
__________________
Please note that I do not use the Friend-feature, so do not be offended, if I do not accept a request.
ngj is offline   Reply With Quote

Old   June 3, 2020, 08:01
Default
  #3
ngj
Senior Member
 
Niels Gjoel Jacobsen
Join Date: Mar 2009
Location: Deltares, Delft, The Netherlands
Posts: 1,864
Rep Power: 33
ngj will become famous soon enoughngj will become famous soon enough
I made a quick check and your problem is most likely in your own script. Reverse engineering suggests that you have calculated the wave numbers based on shallow water wave theory and this is not generally applicable for irregular wave spectra.

Repeat your calculation with spectra calculated using the setWaveParameters tool and your results are most likely to improve considerably.

Kind regards

Niels
__________________
Please note that I do not use the Friend-feature, so do not be offended, if I do not accept a request.
ngj is offline   Reply With Quote

Old   June 5, 2020, 11:39
Default
  #4
New Member
 
Marc Batlle
Join Date: Mar 2017
Posts: 8
Rep Power: 5
Marc Batlle is on a distinguished road
Hi Niels,

First thanks for your contribution and dedication to CFD Online as well as OpenFOAM.
Secondly, thanks for your quick and helpful reply.

A simulation is ongoing at the moment with the corresponding correction on the wave number definition. So far, the issue seems that no longer happens.

Thanks again, I really appreciate your time.

Marc

Ps: I will pay more attention to the "ask a question" recommendations next time
Marc Batlle is offline   Reply With Quote

Reply

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
Centrifugal fan-reverse flow in outlet lesds to a mass in flow field xiexing CFX 3 March 29, 2017 10:00
Velocity vector in impeller passage ngoc_tran_bao CFX 24 May 3, 2016 21:16
sliding mesh problem in CFX Saima CFX 45 September 22, 2015 10:53
Wrong flow in ratating domain problem Sanyo CFX 17 August 15, 2015 06:20
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 15:55


All times are GMT -4. The time now is 19:35.