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-   -   Parabolic inlet velocity profile (https://www.cfd-online.com/Forums/openfoam-solving/57793-parabolic-inlet-velocity-profile.html)

ata August 8, 2010 06:29

Parabolic inlet velocity profile
 
Hi
I think you can use groovy boundary condition and transform cylindrical cordinate to cartesian.
Good luck

Ata

heavy_user August 9, 2010 06:08

Quote:

Originally Posted by pradeeppandeygbpec (Post 270629)
hello...all..
i need to prescribe parabolic velocity profile at inlet to a 3-D circular pipe . The pipe is along the x-Axis...ie. x-axis as its centerline.
I know the parabolic velocity profile for cylindrical coordinates system but how to implement the same in Cartesian coordinates....i need "u" as a function of x,y,z at inlet.
plz help me out...

Hi There,

i postet a while ago(further up somewhere) a "tool" that should be able to do that.
Just download and insert your equation...hope it works..

regards

gascortado January 21, 2011 14:08

setParabolicInlet.C
 
Hi. Does anyone have setParabolicInlet.C file previously posted? It is not available any more. If anyone can email it to gascortado@gmail.com I will greately appreciate it. Thanks

ngj January 22, 2011 14:01

Hi

You would be better off considering the tool swak4foam: http://openfoamwiki.net/index.php/Contrib/swak4Foam

Have a nice weekend,

Niels

kbambas May 2, 2011 04:44

information in parabolic inlet
 
Good morning evryone!
I 'm new in OpenFoam ,i want set parabolic inlet.I use the version 1.7.0. my geometry is a canal with attach in a tab.I have read in forom but i don't understand.
Please some help me to explain the procedure.
I try to english but my language is french.

desert_1250 August 25, 2011 15:38

Hi
 
Hi all, can every one tell me how to define U0=1-exp(-y^2) profile at the inlet BCs?


_____
Rasoul

gschaider August 25, 2011 17:31

Quote:

Originally Posted by desert_1250 (Post 321635)
Hi all, can every one tell me how to define U0=1-exp(-y^2) profile at the inlet BCs?

If you like C++-programming you can do it with codedFixedValue (only in 2.0). There was a discussion on that in the forum today

Or you can do it with groovyBC (now part of the swak4Foam-package). You find info about that either inthe Forum or on the Wiki

desert_1250 August 26, 2011 02:09

Quote:

Originally Posted by gschaider (Post 321658)
If you like C++-programming you can do it with codedFixedValue (only in 2.0). There was a discussion on that in the forum today

Or you can do it with groovyBC (now part of the swak4Foam-package). You find info about that either inthe Forum or on the Wiki


tanx for your reply, i have not any information about swak4Foam and not have enough time to study it, would you tell me the simplest way to set this BCs at the inlet? (i used OF.1.5-dev)

________
Rasoul

gschaider August 26, 2011 04:24

Quote:

Originally Posted by desert_1250 (Post 321685)
tanx for your reply, i have not any information about swak4Foam and not have enough time to study it, would you tell me the simplest way to set this BCs at the inlet? (i used OF.1.5-dev)

________
Rasoul

Unless you know the OpenFOAM-API by heart and program two boundary conditions every day (before breakfast) in my opinion groovyBC is the fastest way to get what you want (BTW: for your OF version you'll have to use "old school" groovyBC. Advantage: compilation is faster)

As you're very short on time: http://tinyurl.com/3fklrwd

desert_1250 August 26, 2011 12:20

Quote:

Originally Posted by gschaider (Post 321706)
Unless you know the OpenFOAM-API by heart and program two boundary conditions every day (before breakfast) in my opinion groovyBC is the fastest way to get what you want (BTW: for your OF version you'll have to use "old school" groovyBC. Advantage: compilation is faster)

As you're very short on time: http://tinyurl.com/3fklrwd


i successed to set the Bcs that i mentioned in the last posts by using nonuniform BCs. now i wanna to add osscillation to the inlet after reaching to the steady state. i know how to use oscillating bc, but dont know how to set it be continued from previous issue!!!??? on the other hand i wanna set unsteady BCs so that after a special time that the problem reached to the steady state, apply oscillation at the inlet. whoud you tell me how do it?? tanx

__________
Rasoul

desert_1250 August 27, 2011 03:25

can every one tell me how to exert (1-exp(-y^2)+0.5Cos2t) profile at the inlet BCs by groovy BCs?? i did not find any manual for groovyBC so that help me do it, i am very glad if intruduce me any documention a bout it.

_____
Rasoul

gschaider August 27, 2011 11:14

Quote:

Originally Posted by desert_1250 (Post 321873)
can every one tell me how to exert (1-exp(-y^2)+0.5Cos2t) profile at the inlet BCs by groovy BCs?? i did not find any manual for groovyBC so that help me do it, i am very glad if intruduce me any documention a bout it.

_____
Rasoul

You asked the same question in three threads in under an hour. Rule of thumb: usually this makes it LESS likely that anyone cares to answer. See also http://openfoamwiki.net/index.php/Ho..._Message_Board
(especially points 5&7)

desert_1250 August 27, 2011 13:10

tnx for your attention, you are right!!!
I've done my work with a combination of two other boundary conditions, without use groovyBC :))

alberto August 27, 2011 22:13

Ehhh...there are many examples on the download page of GroovyBC, so it's really a question of *reading* before asking.

desert_1250 August 28, 2011 02:11

Quote:

Originally Posted by alberto (Post 321939)
Ehhh...there are many examples on the download page of GroovyBC, so it's really a question of *reading* before asking.

you are right too :eek: someone else no idea ... :cool:

_______
Rasoul

sihaqqi March 22, 2013 10:00

Hello Håkan

I am going through your tutorial. I am using OpenFoam 2.1. I am a beginner and freshly started learning openFoam. I cannot find parabolicvelocity folder and relevant files in the path.
parabolicVelocity/parabolicVelocityFvPatchVectorField.C
parabolicVelocity/parabolicVelocityFvPatchVectorField.H

Can you please send them at sihaqqi@gmail.com. I shall be very grateful. I have tried to find them on internet but every link is useless.

Thanks and Regards

wyldckat January 2, 2014 18:17

Quote:

Originally Posted by sihaqqi (Post 415738)
I am going through your tutorial. I am using OpenFoam 2.1. I am a beginner and freshly started learning openFoam. I cannot find parabolicvelocity folder and relevant files in the path.
parabolicVelocity/parabolicVelocityFvPatchVectorField.C
parabolicVelocity/parabolicVelocityFvPatchVectorField.H

FYI: The way to get those files and build them (for any OpenFOAM version) is fully explained here: http://www.cfd-online.com/Forums/ope...tml#post446451 post #10

shivab February 6, 2020 05:13

Regarding parabolic velocity profile at inlet
 
Hello!

I am trying to give a parabolic velocity profile at the inlet.
I got the default code from Ansys fluent manual, how can I adjust it such as I get a particular velocity at inlet. Initially, I have taken up the code and interpreted and during initialization, I gave the velocity required.

Here is the code I used and any suggestions regarding the improvement of the code to get a required velocity?:

#include "udf.h"
DEFINE_PROFILE(x_velocity,thread,index)
{
real x[ND_ND];
real y;
face_t f;
begin_f_loop(f,thread)
{
F_CENTROID(x,f,thread);
y = x[1];
F_PROFILE(f,thread,index) = 20. - y*y/(.0745*.0745)*20.;
}
end_f_loop(f,thread)
}

Regards,
Shiva


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