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

Linear Velocity Inlet Boundary Condition in Openfoam

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By Bloerb

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 26, 2016, 19:11
Question Linear Velocity Inlet Boundary Condition in Openfoam
  #1
New Member
 
Shahil
Join Date: Jan 2016
Posts: 5
Rep Power: 10
shahilc is on a distinguished road
I am analyzing turbulent flow over a flat plate and I am trying to specifying inlet velocity as U = Sx*y; where y is the wall-normal co-ordinate and Sx is shear rate, the value I calculated as 11800.
In boundary condition folder for U, I tried specifying linear inlet velocity as follows:

inlet
{
type uniformValue;
uniformValue polynomial
(
( ( 11800 0 0 ) ( 1 0 0 ) )
);
}
The solver is showing following error.

file: /air/U.boundaryField.inlet from line 31 to line 32.

From function fvPatchField<Type>::New(const fvPatch&, const DimensionedField<Type, volMesh>&, const dictionary&)
in file /home/lab/OpenFOAM/OpenFOAM-2.3.x/src/finiteVolume/lnInclude/fvPatchFieldNew.C at line 143.

FOAM exiting


Please give your suggestions.


Please help.
shahilc is offline   Reply With Quote

Old   February 27, 2016, 04:00
Default
  #2
Senior Member
 
Join Date: Sep 2013
Posts: 353
Rep Power: 21
Bloerb will become famous soon enough
polynomial works in the following way:

Code:
uniformValue     polynomial // y = 0.1 + 1.3x^2 + 2.7x^3       
(       
    (0.1     0)       
    (1.3   2.0)       
    (2.7   3.0)       
);
for a vector it is therefore

Code:
uniformValue     polynomial // y = 0.1 + 1.3x^2 + 2.7x^3       
(       
    (0.1     (0 0 0))       
    (1.3   (0 0 2.0))       
    (2.7   (0 0 3.0))       
);
this is a time varying boundary condition that assignes a uniform value that is interpolated using the given polynomial. I suppose you want a boundary condition that gives you such a velocity profile
.../
../
./
/
You could check if sawkForFoam offers this or program your own. For this purpose you could take a look at the parabolic inlet boundary conditions.
Mahmoud Abbaszadeh likes this.
Bloerb is offline   Reply With Quote

Reply

Tags
boundary condition, pre-processing, u folder, velocity inlet


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
Inlet boundary condition with existed velocity profile wanjia SU2 9 May 10, 2017 06:33
how to set complex boundary condition, namely a developed velocity in inlet of pipe? milad653279 OpenFOAM Pre-Processing 3 January 4, 2016 10:46
Problem with assigned inlet velocity profile as a boundary condition Ozgur_ FLUENT 5 August 25, 2015 05:58
velocity profile inlet boundary condition question Lcw FLUENT 3 August 3, 2012 06:53
Velocity inlet boundary condition for porous medium Chander CFX 3 March 11, 2012 22:18


All times are GMT -4. The time now is 15:08.