CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Pre-Processing

Bounday conditions for a natural convection boundary layer

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 26, 2015, 10:30
Default Bounday conditions for a natural convection boundary layer
  #1
Senior Member
 
Agustín Villa
Join Date: Apr 2013
Location: Brussels
Posts: 159
Rep Power: 6
agustinvo is on a distinguished road
Hello!

I am setting up a natural convection boundary layer, where I impose a heat source (heat flux or fixed temperature) at a wall, but I don't know if the set up I am planning is good enough.

In the figure you can see my initial set up, and I will use buoyantBoussinesqPimpleFoam. The BC's I am imposing are:
  • Velocity
    • Wall = [0 0 0]
    • Inlet & outlet = zeroGradient
    • Free Stream = zeroGradient
  • Temperature
    • Wall = fixedTemperature_1 or turbulentHeatFluxTemperature
    • Inlet = fixedTemperature_2 (fixedTemperature_1>fixedTemperature_2)
    • Free Stream = zeroGradient
  • k,epsilon, nut: low Re correction at the wall, zeroGradient in the rest of boundaries
  • p_rgh: equal to 0 at inlet, zeroGradient in the rest of boundaries
I am wondering if I should move to fixedValues in the Free Stream boundary (T_inf and U=[0 0 0]), but I don't like this idea since it will affect my boundary layer profiles, and setting very far from the wall this boundary can be done at this moment, but not in the future (LES simulations are planned).


If you think that I could improve my simulation by modifying some parameters, I would be grateful! Thank you!
Attached Images
File Type: png flowRoot4326-8-5.png (18.0 KB, 21 views)
agustinvo is offline   Reply With Quote

Old   October 30, 2015, 09:06
Default
  #2
New Member
 
Dominik
Join Date: Oct 2015
Location: Stuttgart
Posts: 8
Rep Power: 3
dodobenq is on a distinguished road
Hey Agustín,

I want to simulate the same case. Do you have some News? Do you have improved/modified your parameters?

Kind Regards!
dodobenq is offline   Reply With Quote

Old   October 30, 2015, 12:08
Default
  #3
Senior Member
 
Agustín Villa
Join Date: Apr 2013
Location: Brussels
Posts: 159
Rep Power: 6
agustinvo is on a distinguished road
Hello Dominik,

I am still dealing with the boundary conditions. I am imposing inletOutlet for temperature in the free stream region and inlet, and a zeroGradient at the outlet.

For velocity I set zeroGradient, and the pressure is now my problem. Recently I have know about fixedFluxPressure and buoyantPressure (the last one not available in 2.3.x), and I want to use them and see their effect.

In the other hand, the solver is always a pain. I have developed an incompressible solver which is not working ok at all, and there is other option: to use buoyantPimpleFoam with an incompressible configuration.

And you? How is it going on?
agustinvo is offline   Reply With Quote

Reply

Tags
boundary layer, boussinesq approximation, natural convection, turbulence

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
sliding mesh problem in CFX Saima CFX 45 September 22, 2015 10:53
RPM in Wind Turbine Pankaj CFX 9 November 23, 2009 05:05
Convective Heat Transfer - Heat Exchanger Mark CFX 6 November 15, 2004 16:55
New topic on same subject - Flow around race car Tudor Miron CFX 15 April 2, 2004 06:18
errors Fahad Main CFD Forum 0 March 23, 2004 14:20


All times are GMT -4. The time now is 20:35.