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

Multiple inlets with different temperatures in compressible flow, boundary condition

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 20, 2016, 00:15
Default Multiple inlets with different temperatures in compressible flow, boundary condition
  #1
Member
 
Join Date: Oct 2013
Posts: 92
Rep Power: 12
fedvasu is on a distinguished road
Hi,

I have a very basic question, what should be the outlet boundary condition if I have multiple inlets with different fluid velocity and temperature?

I am currently using something like this

Code:
Inlet0
    {
        type             fixedValue;
        value            uniform 1000;
    }

    Inlet1
    {
        type              fixedValue;
        value             uniform 300;
    }

    Inlet2
    {
     	type             fixedValue;
	value            uniform 300;
    }

    outlet
    {
     	type          inletOutlet;
	value         300;
	inletValue    300;
    }
my solver is rhopimplefoam. is that OK?

Any corrections welcome.
fedvasu is offline   Reply With Quote

Old   July 24, 2016, 14:44
Default
  #2
Senior Member
 
Join Date: Sep 2010
Posts: 226
Rep Power: 16
T.D. is on a distinguished road
Hi,

It depends on what you need to do exactly..

regards,
T.D.
T.D. is offline   Reply With Quote

Old   August 4, 2016, 10:13
Default
  #3
Member
 
Join Date: Oct 2013
Posts: 92
Rep Power: 12
fedvasu is on a distinguished road
Quote:
Originally Posted by T.D. View Post
Hi,

It depends on what you need to do exactly..

regards,
T.D.
I just want a simple mixing of two streams which have different velocity and temperature.
(interested in mixing pattern)

I don't much care for the outlet as long as it is consistent.
fedvasu is offline   Reply With Quote

Old   August 4, 2016, 10:23
Default
  #4
Senior Member
 
Join Date: Sep 2010
Posts: 226
Rep Power: 16
T.D. is on a distinguished road
Hi,

you can use "type zeroGradient" for velocity at outlet,
and for pressure:
outlet { type fixedValue; value uniform 0; }

Good Luck

regards,
T.D.
T.D. is offline   Reply With Quote

Old   August 4, 2016, 10:37
Default
  #5
Member
 
Join Date: Oct 2013
Posts: 92
Rep Power: 12
fedvasu is on a distinguished road
Quote:
Originally Posted by T.D. View Post
Hi,

you can use "type zeroGradient" for velocity at outlet,
and for pressure:
outlet { type fixedValue; value uniform 0; }

Good Luck

regards,
T.D.
Thanks TD,

But does uniform 0 pressure makes sense?

because the pressure is physical pressure isn't it? I have kept outlet as 1 atm, same as internalfield and velocity is as you have mentioned.

But I am not so sure about temperature.
fedvasu is offline   Reply With Quote

Old   June 12, 2018, 17:39
Default
  #6
Member
 
Join Date: Oct 2013
Posts: 92
Rep Power: 12
fedvasu is on a distinguished road
Quote:
Originally Posted by fedvasu View Post
Thanks TD,

But does uniform 0 pressure makes sense?

because the pressure is physical pressure isn't it? I have kept outlet as 1 atm, same as internalfield and velocity is as you have mentioned.

But I am not so sure about temperature.
Old thread of mine, now I know more.

Whenever in doubt use zeroGradient for velocity and other scalars(temeprature, species mass fractions etc) for outlet.

and fixedValue for pressure for the outlet.(typically ambient pressure).
fedvasu is offline   Reply With Quote

Reply

Tags
rhopimplefoam, temperature bc

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
Appropriate pressure boundary condition in incompressible flow lonelywing OpenFOAM Running, Solving & CFD 21 June 6, 2022 09:44
Suitable inlet boundary condition for a compressible flow simulation siw FLUENT 13 October 9, 2018 23:54
Outlet boundary condition for compressible nozzle flows blais.bruno OpenFOAM Running, Solving & CFD 0 July 12, 2016 08:40
Boundary condition problem for open channel flow Andy CFX 9 June 11, 2016 07:20
Compressible Flow - Boundary Conditions Marc FLUENT 1 July 20, 2007 11:04


All times are GMT -4. The time now is 20:55.