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

Katabatic flow using buoyantboussinesqpisofoam

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 18, 2013, 11:30
Default Katabatic flow using buoyantboussinesqpisofoam
  #1
New Member
 
Join Date: May 2011
Posts: 6
Rep Power: 15
tsauter is on a distinguished road
Hi all,

I am using a bouyantBoussinesq solver (LES) to model a katabatic wind flow along a slope. The surface temperature (wall) is slightly cooler than the overlying stably stratified atmosphere (see figure 1).

I like to use cyclic boundary conditions for the left and right patch, in order to get a fully developed turbulent wind field. Since the inlet and outlet are not at the same height, this causes a jump of the pressure field (see picture 2).

It is probably not possible to use a cyclic boundary condition here, or is there a way to solve this problem?

The other solution might be to rotate the frame of reference by aligning the x-axis with the slope, but I am not quite sure how to do this.

Thank you in advance
Tobias
Attached Images
File Type: png p.png (4.6 KB, 15 views)
Attached Files
File Type: pdf katabaticFlow.pdf (12.5 KB, 18 views)
tsauter is offline   Reply With Quote

Old   April 19, 2013, 04:43
Default
  #2
Senior Member
 
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,267
Blog Entries: 1
Rep Power: 25
nimasam is on a distinguished road
you can use cyclic BC with pressure Jump, pressure Jump can be accessed by fan type BC at inlet-outlet, search in forum about fan BC
__________________
My Personal Website (http://nimasamkhaniani.ir/)
Telegram channel (https://t.me/cfd_foam)
nimasam is offline   Reply With Quote

Old   April 19, 2013, 05:05
Default
  #3
New Member
 
Join Date: May 2011
Posts: 6
Rep Power: 15
tsauter is on a distinguished road
Hi Nima Sam,

Thank you very much for your response. I'll check it out.

Cheers,
Tobias
tsauter is offline   Reply With Quote

Old   April 19, 2013, 10:09
Default
  #4
New Member
 
Join Date: May 2011
Posts: 6
Rep Power: 15
tsauter is on a distinguished road
Hi Niam,

I have applied the following boundary conditions to the left and right patch, respectively. But the result is still the same. Do I make something wrong?

Code:
    
left
    {
        type             fan;
        patchType     cyclic;
        jump           uniform 0;
        f                 2(100 -1.0);
        value           uniform 0;
    }
    right
    {
        type             fan;
        patchType     cyclic;
        jump            uniform 0;
        f                 2(100 -1.0);
        value           uniform 0;
    }
Thank you very much.
Tobias
tsauter is offline   Reply With Quote

Reply

Tags
buoyantboussinesqpisofoam, cyclic boundaries, les model, pressure boundary

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
mass flow in is not equal to mass flow out saii CFX 12 March 19, 2018 06:21
Different flow patterns in CFX and Fluent avi@lpsc FLUENT 4 April 8, 2012 07:12
Flow meter Design CD adapco Group Marketing Siemens 3 June 21, 2011 09:33
potential flow vs. Euler flow curious ... Main CFD Forum 23 July 21, 2006 08:40
Plug Flow Franck Main CFD Forum 3 September 4, 2003 06:57


All times are GMT -4. The time now is 01:29.