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

icoFoam- unphysical results

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 11, 2013, 02:22
Default icoFoam- unphysical results
  #1
Member
 
Amin
Join Date: May 2013
Posts: 76
Rep Power: 4
Mirage12 is on a distinguished road
Hello world

I wanted to simulate a incompressible flow around the cylinder (Re 100), but unlikely after running the simulation (8.236 sec) the solver crashed and results look not correct.


in the attachement please find a screen-shot of the case (time 8.232 sec).

time-step 0.0001 s

BC for U :

Code:
internalField   uniform (1 0 0);

boundaryField
{
    inlet
    {
        type            freestream;
        freestreamValue uniform (1 0 0);
    }

    outlet
    {
        type            freestream;
        freestreamValue uniform (1 0 0);
    }

    fixedWalls
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }

    frontAndBack
    {
        type            empty;
    }
}
why are the results not correct ?
Do you know, how to stabilize icoFoam ?
Attached Images
File Type: jpg error.jpg (32.4 KB, 7 views)
Mirage12 is offline   Reply With Quote

Old   July 11, 2013, 03:33
Default
  #2
Senior Member
 
akidess's Avatar
 
Anton Kidess
Join Date: May 2009
Location: Delft, Netherlands
Posts: 919
Rep Power: 17
akidess will become famous soon enough
How to give enough info to get help
__________________
*On twitter @akidTwit
*Spend as much time formulating your questions as you expect people to spend on their answer.
*Help define the OpenFOAM stackexchange Q&A site: http://area51.stackexchange.com/prop...oam-technology
akidess is offline   Reply With Quote

Old   July 12, 2013, 03:52
Default
  #3
Member
 
Amin
Join Date: May 2013
Posts: 76
Rep Power: 4
Mirage12 is on a distinguished road
Thanks akidess,

Here is my blockMesh :

Code:
// The OpenFOAM Project // File: blockMeshDict
  /*
  -------------------------------------------------------------------------------
   =========         | dictionary
   \\      /         |
    \\    /          | Name:   blockMeshDict
     \\  /           | Family: FoamX configuration file
      \\/            |
      F ield         | OpenFOAM version: 2.3
      O peration     | Product of Nabla Ltd.
      A and          |
      M anipulation  | author: Amine Abdelmoula
  -------------------------------------------------------------------------------
  */
  // FoamX Case Dictionary.
  
  FoamFile
  {
      version         2.0;
      format          ascii;
  
      root            "";
      case            "";
      instance        "";
      local           "";
  
      class           dictionary;
      object          blockMeshDict;
  }
 
  // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
  
 convertToMeters 1;
  
  vertices
  (
      (0.5 0 -0.5)//0----------------------------1. HAELFTE VON DEM BODEN
      (1 0 -0.5)//1
      (30 0 -0.5)//2
      (30 0.707107 -0.5)//3
      (0.707107 0.707107 -0.5)//4
      (0.353553 0.353553 -0.5)//5
      (30 8 -0.5)//6
      (0.707107 8 -0.5)//7
      (0 8 -0.5)//8
      (0 1 -0.5)//9
      (0 0.5 -0.5)//10
      (-0.5 0 -0.5)//11
      (-1 0 -0.5)//12
      (-6 0 -0.5)//13
      (-6 0.707107 -0.5)//14
      (-0.707107 0.707107 -0.5)//15
      (-0.353553 0.353553 -0.5)//16
      (-6 8 -0.5)//17
      (-0.707107 8 -0.5)//18----------------------------------------------------
      (0.5 0 0.5)//19----------------------------1. HAELFTE VON DEM DECKEL
      (1 0 0.5)//20
      (30 0 0.5)//21
      (30 0.707107 0.5)//22
      (0.707107 0.707107 0.5)//23
      (0.353553 0.353553 0.5)//24
      (30 8 0.5)//25
      (0.707107 8 0.5)//26
      (0 8 0.5)//27
      (0 1 0.5)//28
      (0 0.5 0.5)//29
      (-0.5 0 0.5)//30
      (-1 0 0.5)//31
      (-6 0 0.5)//32
      (-6 0.707107 0.5)//33
      (-0.707107 0.707107 0.5)//34
      (-0.353553 0.353553 0.5)//35
      (-6 8 0.5)//36
      (-0.707107 8 0.5)//37----------------------------------------------------
      (30 -0.707107 -0.5)//38----------------------------2.HAELFTE VON DEM BODEN
      (0.707107 -0.707107 -0.5)//39
      (0.353553 -0.353553 -0.5)//40
      (30 -8 -0.5)//41
      (0.707107 -8 -0.5)//42
      (0 -8 -0.5)//43
      (0 -1 -0.5)//44
      (0 -0.5 -0.5)//45
      (-6 -0.707107 -0.5)//46
      (-0.707107 -0.707107 -0.5)//47
      (-0.353553 -0.353553 -0.5)//48    
      (-6 -8 -0.5)//49
      (-0.707107 -8 -0.5)//50----------------------------------------------------
      (30 -0.707107 0.5)//51----------------------------2.HAELFTE VON DEM DECKEL
      (0.707107 -0.707107 0.5)//52
      (0.353553 -0.353553 0.5)//53
      (30 -8 0.5)//54
      (0.707107 -8 0.5)//55
      (0 -8 0.5)//56
      (0 -1 0.5)//57
      (0 -0.5 0.5)//58
      (-6 -0.707107 0.5)//59
      (-0.707107 -0.707107 0.5)//60
      (-0.353553 -0.353553 0.5)//61    
      (-6 -8 0.5)//62
      (-0.707107 -8 0.5)//63--------------
      
  );
  
  blocks
  (
      hex (5 4 9 10 24 23 28 29) (20 20 1) simpleGrading (1 1 1) // 0--------------------BLOECKE IM OBEREN BEREICH
      hex (0 1 4 5 19 20 23 24) (20 20 1) simpleGrading (1 1 1)// 1
      hex (1 2 3 4 20 21 22 23) (70 20 1) simpleGrading (60 1 1)//2
      hex (4 3 6 7 23 22 25 26) (70 100 1) simpleGrading (60 4 1)// 3
      hex (9 4 7 8 28 23 26 27) (20 100 1) simpleGrading (1 4 1)//4
      hex (15 16 10 9 34 35 29 28) (20 20 1) simpleGrading (1 1 1)//5
      hex (12 11 16 15 31 30 35 34) (20 20 1) simpleGrading (1 1 1)//6
      hex (13 12 15 14 32 31 34 33) (70 20 1) simpleGrading (0.1 1 1)//7
      hex (14 15 18 17 33 34 37 36) (70 100 1) simpleGrading (0.1 4 1)//8
      hex (15 9 8 18 34 28 27 37) (20 100 1) simpleGrading (1 4 1)//9--------------------BLOECKE IM UNTEREN BEREICH
      hex (44 39 40 45 57 52 53 58) (20 20 1) simpleGrading (1 1 1)//10
      hex (40 39 1 0 53 52 20 19) (20 20 1) simpleGrading (1 1 1)//11
      hex (39 38 2 1 52 51 21 20) (70 20  1) simpleGrading (60 1 1)//12
      hex (42 41 38 39 55 54 51 52) (70 100 1) simpleGrading (60 0.2 1)//13
      hex (43 42 39 44 56 55 52 57) (20 100 1) simpleGrading (1 0.2 1)//14
      hex (47 44 45 48 60 57 58 61) (20 20 1) simpleGrading (1 1 1)//15
      hex (47 48 11 12 60 61 30 31) (20 20 1) simpleGrading (1 1 1)//16
      hex (46 47 12 13 59 60 31 32) (70 20 1) simpleGrading (0.1 1 1)//17
      hex (49 50 47 46 62 63 60 59) (70 100 1) simpleGrading (0.1 0.2 1)//18
      hex (50 43 44 47 63 56 57 60) (20 100 1) simpleGrading (1 0.2 1)//19

  );
  
  edges
  (
      arc 0 5 (0.469846 0.17101 -0.5)
      arc 5 10 (0.17101 0.469846 -0.5)
      arc 4 1 (0.939693 0.34202 -0.5)
      arc 9 4 (0.34202 0.939693 -0.5)
      arc 19 24 (0.469846 0.17101 0.5)
      arc 24 29 (0.17101 0.469846 0.5)
      arc 20 23 (0.939693 0.34202 0.5)
      arc 23 28 (0.34202 0.939693 0.5)
      arc 16 11 (-0.469846 0.17101 -0.5)
      arc 10 16 (-0.17101 0.469846 -0.5)
      arc 12 15 (-0.939693 0.34202 -0.5)
      arc 15 9 (-0.34202 0.939693 -0.5)
      arc 30 35 (-0.469846 0.17101 0.5)
      arc 35 29 (-0.17101 0.469846 0.5)
      arc 31 34 (-0.939693 0.34202 0.5)
      arc 34 28 (-0.34202 0.939693 0.5)
      arc 40 0 (0.469846 0.17101 -0.5)//--- 
      arc 45 40 (0.17101 0.469846 -0.5)
      arc 1 39 (0.939693 -0.34202 -0.5)
      arc 39 44 (0.34202 -0.939693 -0.5)
      arc 19 53 (0.469846 -0.17101 0.5)
      arc 53 58 (0.17101 -0.469846 0.5)
      arc 20 52 (0.939693 -0.34202 0.5)
      arc 52 57 (0.34202 -0.939693 0.5)
      arc 11 48 (-0.469846 -0.17101 -0.5)
      arc 48 45 (-0.17101 -0.469846 -0.5)
      arc 47 12 (-0.939693 -0.34202 -0.5)
      arc 44 47 (-0.34202 -0.939693 -0.5)
      arc 30 61 (-0.469846 -0.17101 0.5)
      arc 61 58 (-0.17101 -0.469846 0.5)
      arc 31 60 (-0.939693 -0.34202 0.5)
      arc 60 57 (-0.34202 -0.939693 0.5) 

  );
  
boundary
(

 inlet
    {
        type patch;
        faces
        (
          
    (17 14 33 36)
    (14 13 32 33)
    (13 46 59 32)
    (46 49 62 59)      
  );
    }
    outlet
    {
        type patch;
        faces
        ( 
            (3 6 25 22)
            (2 3 22 21)
            (38 2 21 51)
        (41 38 51 54)    
            
       
               
        );
    }
 
    fixedWalls
    {
        type wall;
        faces
        (

          (18 17 36 37)
          (8 18 37 27)
          (7 8 27 26)
          (6 7 26 25)
          (49 50 63 62)
          (50 43 56 63)
       (43 42 55 56)
          (42 41 54 55)
      (11 16 35 30)
          (16 10 29 35)
      (10 5 24 29)
          (5 0 19 24)
      (11 48 61 30)
          (48 45 58 61)
      (45 40 53 58)
          (40 0 19 53)
      
           );
    }      

    frontAndBack
    {
        type empty;
        faces
        (  
           (2 1 4 3)
       (3 4 7 6)
           (4 9 8 7)
           (9 15 18 8)
           (15 14 17 18)
           (12 13 14 15)
           (47 46 13 12)
           (50 49 46 47)
           (43 50 47 44)
           (42 43 44 39)
           (41 42 39 38)
           (38 39 1 2)
           (1 0 5 4)
           (4 5 10 9)
           (9 10 16 15)
           (15 16 11 12)
           (12 11 48 47) 
              (47 48 45 44)
        (45 40 39 44)
        (40 0 1 39) //---------------------------
           (20 21 22 23)
           (23 22 25 26)
           (28 23 26 27)
           (34 28 27 37)
           (33 34 37 36)
           (32 31 34 33)
           (59 60 31 32)
           (62 63 60 59)
           (63 56 57 60)
           (56 55 52 57)
           (55 54 51 52)
           (52 51 21 20)
           (19 20 23 24)
           (29 24 23 28)
           (35 29 28 34)
           (31 30 35 34)
           (60 61 30 31)
           (60 57 58 61)
           (57 52 53 58)
           (52 20 19 53)
          
       
        );
    }
);



mergePatchPairs
(
);

// ************************************************************************* //
Time step : dt=0.0001

i will run the case again and upload the output of OpenFOAM
Attached Images
File Type: jpg mesh2.jpg (94.0 KB, 4 views)
File Type: jpg mesh1.jpg (91.8 KB, 4 views)
Mirage12 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
Oscillating Airfoil Poor Results at High k (reduced frequency) dancfd OpenFOAM Running, Solving & CFD 3 November 4, 2013 09:32
Creating a tool to interpolate results Luis Batista OpenFOAM Running, Solving & CFD 2 April 11, 2013 08:15
Transient Run - Output "Time" in partial results? evcelica CFX 2 May 16, 2012 21:36
OpenFOAM - Validation of Results Ahmed OpenFOAM Running, Solving & CFD 9 June 22, 2011 18:59
CFX cylinder or sphere benchmark results Mel CFX 1 August 8, 2005 18:47


All times are GMT -4. The time now is 09:03.