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-   -   how to derive relative velocity in MRFSimpleFoam? (http://www.cfd-online.com/Forums/openfoam-solving/71277-how-derive-relative-velocity-mrfsimplefoam.html)

renyun0511 December 22, 2009 23:26

how to derive relative velocity in MRFSimpleFoam?
 
hi all,
as we known,the velocity derived from MRFSimpleFoam is absolute velocity,and my problem is that how can i derive relative velocity from it?

thanks
jennifer

waynezw0618 December 22, 2009 23:42

Quote:

Originally Posted by renyun0511 (Post 240787)
hi all,
as we known,the velocity derived from MRFSimpleFoam is absolute velocity,and my problem is that how can i derive relative velocity from it?

thanks
jennifer

I will send you my utilities. which i remember i have ever send it to you before

Santana June 30, 2010 13:22

Hello Wayne,

I am simulating an impeller/diffuser stage case and I want to visualize the impeller relative velocity.

Could you kindly send me the utility too?

Many thanks,

San

aldo.iannetti February 8, 2011 05:57

How to write relative velocity in MRFSimpleFoam
 
Quote:

Originally Posted by waynezw0618 (Post 240789)
I will send you my utilities. which i remember i have ever send it to you before

Hi
can you please send me your utilities to write relative velocity in MRFSimpleFoam?
Thanks
Aldo

renyun0511 February 13, 2011 02:42

Quote:

Originally Posted by aldo.iannetti (Post 294144)
Hi
can you please send me your utilities to write relative velocity in MRFSimpleFoam?
Thanks
Aldo

Attachment 6480

Good Luck

jennifer

renyun0511 February 13, 2011 02:44

Quote:

Originally Posted by Santana (Post 265183)
Hello Wayne,

I am simulating an impeller/diffuser stage case and I want to visualize the impeller relative velocity.

Could you kindly send me the utility too?

Many thanks,

San

Attachment 6481
Good Luck

jennifer

linnemann March 22, 2012 09:31

1 Attachment(s)
Hi

I took the liberty of updating it to a more recent version of OF.

1.6-2.1.x to be exact.

I can see that from 1.6 and onwards the relativeVelocity have been part of the std MRF files so this makes the code much simpler as it is possible to call the relativeVelocity directly

Best

linnemann May 16, 2013 04:27

3 Attachment(s)
Here is one that works for OF-2.2.x

EDIT:
MRF has changed a lot in 2.2 and some solvers are using the MRFProperties file in the constant folder and some are using the system/fvOptions.

EDIT2:
Just place the MRFProperties file in the constant folder with the same info as the one from system/fvOptions then this new version works.

sharonyue May 16, 2013 05:17

Quote:

Originally Posted by linnemann (Post 427929)
Here is one that works for OF-2.2.x

Thanks very much linnemann! Its beautiful!

Regards

renyun0511 May 17, 2013 09:23

Quote:

Originally Posted by linnemann (Post 427929)
Here is one that works for OF-2.2.x

Hi, Linnemann,

Do you have the Urel Utilities for OF-2.1.0?

Thanks,

Yun Ren

renyun0511 May 17, 2013 09:28

Sorry, Ithink I find it. I ignored your upper message!

Quote:

Hi

I took the liberty of updating it to a more recent version of OF.

1.6-2.1.x to be exact.

I can see that from 1.6 and onwards the relativeVelocity have been part of the std MRF files so this makes the code much simpler as it is possible to call the relativeVelocity directly


sharonyue May 27, 2013 21:16

1 Attachment(s)
Quote:

Originally Posted by linnemann (Post 427929)
Here is one that works for OF-2.2.x

Hi Linnemann,

Sorry,very late!I just made a plot over line to check this Urel.But its absolutely the same with U,see the image below,Urel(1) and U(1) coincide exactly.and its the same with U(2) Urel(2).Any ideas?Thanks for your reply!

linnemann May 29, 2013 03:10

Hi see post

http://www.cfd-online.com/Forums/ope...tml#post427929

Lisandro Maders July 8, 2014 05:07

What does Urel do in true?
 
Hi,

What does this Urel do in true? Regarding to the calculations done, I could find nothing. Is it just an updating of the mesh inside the MRF zone and then subtracting the velocities values from the "original" one?


Regards, Lisandro

Nolwenn September 7, 2014 09:25

Hello,

I compile successfully Urel (OpenFOAM 2.3.x) but when I run Urel after the calculation I see "No MRF models present" and Urel in exactly the same as U.

I have no problem with MRF during calculation, in log.simpleFoam I can see :

Code:

Creating finite volume options from "system/fvOptions"

Selecting finite volume options model type MRFSource
    Source: MRF1
    - applying source for all time
    - selecting cells using cellZone rotationCellZone
    - selected 1344433 cell(s) with volume 457.986


I add the MRFProperties.txt to the constant folder, is there something else to do to calculate Urel ?

Nolwenn

linnemann September 7, 2014 13:00

Hi

it should not be "MRFProperties.txt" but "MRFProperties"

Nolwenn September 7, 2014 13:25

Hi Niels,

Silly me ! Thank you, it works perfectly.

Nolwenn

Maff January 13, 2015 17:08

1 Attachment(s)
I modified the Urel utility so that it reads fvOptions (version 2.3.0).
No need for MRFProperties anymore.
I called it "relU" to avoid confusion.

Seroga February 5, 2015 05:58

Can anybody tell to newbie how to install this utility?

macRC June 2, 2015 09:54

Can anybody tell to newbie how to install this utility?


No one?


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