CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > STAR-CCM+

surface tension, contact angle of Gasoline

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 23, 2012, 01:36
Default surface tension, contact angle of Gasoline
  #1
Member
 
Devesh Baghel
Join Date: Mar 2009
Posts: 38
Rep Power: 8
devesh.baghel is on a distinguished road
Hi

I need to perform fuel tank analysis for vapor phase model. Problem statement is: tank is partially filled with fuel and rest of the volume is occupied by vapor (gaseous phase of Gasoline).
I have to model VOF with surface tension effect for gasoline as working fluid; for this I need to include contact angle of Gasoline with plastic surface.
I tried hard but din't find appropriate data for that.

If somebody have any idea about that.......Please help me ASAP.!!!!!!

Last edited by devesh.baghel; October 25, 2012 at 05:28.
devesh.baghel is offline   Reply With Quote

Old   October 25, 2012, 05:45
Unhappy
  #2
Member
 
Devesh Baghel
Join Date: Mar 2009
Posts: 38
Rep Power: 8
devesh.baghel is on a distinguished road
still no response......!!!!!
devesh.baghel is offline   Reply With Quote

Old   October 25, 2012, 16:35
Default
  #3
Member
 
Reza
Join Date: Mar 2009
Location: Appleton, WI
Posts: 99
Rep Power: 8
triple_r is on a distinguished road
I don't know where you can find such information other than doing the experiment yourself, but might I suggest a sensitivity analysis? You can run a few cases with different contact angles and see if the result that you are interested in changes or not, and if it changes how by how much. If you are lucky (based on the tank dimensions and characteristic velocities that occur during the simulation) you might find that the contact angle plays an insignificant role, so there is no need to loose your sleep over it.

On the other hand, if you are not so lucky, then you might be able to measure it yourself. if you put a single drop of gasoline on a horizontal plastic surface (the same plastic that the tank is made of) and then take a picture of the drop (you might need a macro lens with good magnification), then you can measure the contact angle. Make sure that the surface is clean though.
triple_r is offline   Reply With Quote

Old   October 26, 2012, 06:00
Default
  #4
Member
 
Devesh Baghel
Join Date: Mar 2009
Posts: 38
Rep Power: 8
devesh.baghel is on a distinguished road
Hi,

thanks for your suggestions.
I am trying trial-error method only. In some documents (Zisman plot through google) I found contact angle for Gasoline is around 20-30 degree; I run case with 20 degree it shows quit wettability on wall of tank, which is not fruitfull.

On the other way I found another doc on "lecture on contact angle" saying that Hydro-carbons (Octane - low surface energy fluid) behaves as "Hydrophobic" in nature. So I that confused me about the contact angle for gasoline ?

I do not have facility to do experiment.

Request to CFD users please through some light, if have any idea about that.

Thanks alot for your help..
devesh.baghel is offline   Reply With Quote

Old   October 26, 2012, 16:11
Default
  #5
Senior Member
 
Join Date: Oct 2009
Location: Germany
Posts: 637
Rep Power: 12
abdul099 is on a distinguished road
Surface tension plays only a significant role when the radius of the surface is small (e.g. when you have a lot of sloshing, small droplets etc) or you have very small gaps. But in both cases, you need to have mesh resolution appropriate for resolving this small radius elements.

When it's a more or less stationary tank just filled with gasoline and vapor, surface tension will not change much. So I suggest to spend some minutes and think if you really need surface tension. If not, you might save the time for desperately searching for contact angles.
__________________
We do three types of jobs here:
GOOD, FAST AND CHEAP
You may choose any two!
abdul099 is offline   Reply With Quote

Old   October 29, 2012, 01:11
Default
  #6
Member
 
Devesh Baghel
Join Date: Mar 2009
Posts: 38
Rep Power: 8
devesh.baghel is on a distinguished road
Hi Abdul

Thanking you for your post.
Sloshing is influencing parameter & I guess impact will be there into analysis.
If you do not add surface tension into analysis, fluid just hit the walls and smoothly come to the rest position. so I thought of that to take up surface tension effect into analysis along with thermal effect.

Thanks
devesh.baghel is offline   Reply With Quote

Reply

Tags
contact angle, fuel tank simulation, surface tension

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
help with UDF for contact angle based on contact line velocity gandesk Fluent UDF and Scheme Programming 14 October 29, 2012 14:58
surface tension model sjtusyc CFX 15 September 7, 2012 02:02
surface tension gradient using UDF; surface tension gradient as function of temperatu marimuthusundar Fluent UDF and Scheme Programming 0 June 21, 2012 04:48
reference on surface tension and the contact angle Xicheng Jia Main CFD Forum 3 August 25, 2003 14:57
Surface tension - Continuum Surface Force model Robert Main CFD Forum 0 May 2, 2002 07:34


All times are GMT -4. The time now is 13:48.