CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

An unphysical results in the droplet impact tutorial

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 18, 2021, 03:50
Default An unphysical results in the droplet impact tutorial
  #1
Senior Member
 
A. Min
Join Date: Mar 2015
Posts: 305
Rep Power: 10
alimea is on a distinguished road
Hi everybody

I ran the droplet impact tutorial. However, when I saw the results in ParaView, I faced some teeth on the droplet perimeter (the interface with the air), as can be seen in the following pic.

https://pasteboard.co/K2qPPzE.jpg

While in the reference paper one doesn't see these teeth.

https://pasteboard.co/K2qPiIi.jpg

I have made many changes in the setup case, e.g. increasing and decreasing Betta, increasing Re, decreasing Wi, decreasing and increasing the dt, generating a very smaller grid, etc. But the teeth remained!

Even, I set zero values for etaP and lambda, showing a Newtonian fluid, but they remained. However, when I chose Newtonian constitutive eq. the teeth would be removed. This showed me that this is just because of the numerical process of discretization or solution of Oldroyd-B constitutive eq.

Note: Can you explain to me physically why the authors set zero value for surface tension?
As we know, the droplet impact behavior is totally under the effect of surface tension forces. Nevertheless, when I set a non-zero value for the surface tension coef, e.g. 0.07 N/m, teeth got smaller. But the reference paper solved this problem using sigma = 0 and I must solve it in this situation and get the correct answer.

Do you know what they are, and how to solve them?

Thanks

Last edited by alimea; May 18, 2021 at 22:35.
alimea is offline   Reply With Quote

Reply

Tags
droplet, impact, openfoam, rheotool, tutorial

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
Droplet impact using interIsoFoam DanielRodrigues OpenFOAM Running, Solving & CFD 2 June 14, 2021 06:32
droplet impact onto a wall FelixJJ FLUENT 0 September 25, 2018 13:28
Simulation of charge redistribution of a droplet due to impact on solid multiphaser Main CFD Forum 0 October 5, 2016 04:04
VOF and droplet impact simone marras CFX 4 July 13, 2006 05:54
Impact of Humidity on CFD Results Jerry Main CFD Forum 2 January 26, 2004 14:39


All times are GMT -4. The time now is 03:34.