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

Boundary conditions for a 1-d channel

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 3, 2011, 05:54
Default Boundary conditions for a 1-d channel
  #1
New Member
 
Marco Popesso
Join Date: Jun 2011
Posts: 5
Rep Power: 5
popezmark is on a distinguished road
Hi everyone.
I'm a new Foamer and i need some advice, can you help me please?

I'm trying to run a simple 1-D simulation similar, to the shockTube tutorial, with sonicFoam solver.
I have a rectangular conduit 1d with inlet and outlet patches at the edges, and the other faces are classified "empty".
In the first phase of the simulation, I have, inside the conduit, air with low pressure and temperature, and ZERO velocity. I want to have the inlet OPEN and communicating with a high pressure and temperature air ambience. The outlet is CLOSED like a wall. So, I expect the formation of a shockwave, starting from the inlet and moving towards the outlet, and of course there will be introduction of hot air coming from the outside and passing through the open inlet, compressing the cold air that was inside the conduit. Eventually the shockwave reach the closed outlet and is reflected back.

My question is: what is the most appropriate pressure boundary condition for the inlet? I tried this:

For pressure:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [1 -1 -2 0 0 0 0];

internalField uniform 196000; <-- I'm using Pascal

boundaryField
{
inlet
{
type totalPressure;
gamma 1.4;
p0 353000;
}
outlet
{
type zeroGradient;
}
empty
{
type empty;
}
}


// ************************************************** *********************** //
for temperature:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 1 0 0 0];

internalField uniform 435; <--- kelvin

boundaryField
{
inlet
{
type fixedValue;
value uniform 1589;
}
outlet
{
type zeroGradient;
}
empty
{
type empty;
}
}


// ************************************************** *********************** //

and for velocity:

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet
{
type zeroGradient;
}
outlet
{
type fixedValue;
value uniform (0 0 0); <--- this is for the wall
}
empty
{
type empty;
}
}


// ************************************************** *********************** //

Am I doing correctly?

Thank you everyone.
popezmark is offline   Reply With Quote

Reply

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
boundary conditions in FLUENT VOF for open channel flow newcomer Fluent Multiphase 19 August 25, 2013 09:05
Water subcooled boiling Attesz CFX 7 January 5, 2013 03:32
mesh file for flow over a circular cylinder Ardalan Main CFD Forum 6 April 17, 2010 23:40
mass flow in is not equal to mass flow out saii CFX 2 September 18, 2009 08:07
boundary conditions for open rectangular channel pavan FLUENT 1 March 6, 2007 15:46


All times are GMT -4. The time now is 09:10.