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

Pressure gradient slow and continuously growup

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 23, 2023, 17:12
Default Pressure gradient slow and continuously growup
  #1
New Member
 
Abel Bonfil Garcia
Join Date: Mar 2023
Posts: 2
Rep Power: 0
Abonfil04 is on a distinguished road
Hi, foamers , i'm relatively new in OpenFoam

i'm trying to simulate a centrifugal pump but i'm facing some problems with the pressure grandient, due to it continously grow whitout stopping.

I already try
- fvSchemes modifications
- fvSolutions modifications
- bc's modifications like:
-totalPressure at inlet and flowrate at outlet
-flowrate at inlet and static pressure at outlet

This case is steady-state, i'm using frozen rotor and komegasst

Pump parameters:
- 3600 rpm
- capacity of 608 l/min
- total head of 77.8 m


here some files of my simulation:

U:
Code:
boundaryField
{

    Inlet
    {
        type                     flowRateInletVelocity;
        volumetricFlowRate       uniform 0.010133333;
        value                    uniform (0.0 0.01013 0.0);
    }
    
    Outlet
    {
        type                        inletOutlet;
        inletValue                  uniform (0 0 0);
        value                       uniform (0 0.01013 0);
    }


    "(Wall_1|Wall_2|Wall_3|Wall_4)"
    {
        type            noSlip;
    }



    "(AMI1_2|AMI2_2|AMI3_2|AMI3_1|AMI2_1|AMI1_1)"
    {
        type            cyclicAMI;
    }
}
p:
Code:
boundaryField
{

    Inlet
	{
        type            zeroGradient;
        // outletValue     uniform 0;
        value           uniform 0;
	}

    
    Outlet
	{
        type            fixedValue;
        value           uniform 101.325;
	}

    "(Wall_1|Wall_2|Wall_3|Wall_4)"
    {
        type            zeroGradient;
    }

    "(AMI1_2|AMI2_2|AMI3_2|AMI3_1|AMI2_1|AMI1_1)"
    {
		type			cyclicAMI;
	}
}

fvSchemes:
Code:
ddtSchemes      // unmodifiable
{
    default         steadyState;
}

gradSchemes
{
    default cellMDLimited Gauss linear 0.5;
    grad(U) cellMDLimited Gauss linear 1.0;

}

divSchemes
{
    default                         none;
    div(phi,U)                      Gauss linearUpwind grad(U);
    div(phi,k)                      Gauss upwind;
    div(phi,omega)                  Gauss upwind;
    div((nuEff*dev2(T(grad(U)))))   Gauss linear;
    div(R)                          Gauss linear;
    div(phi,R)                      bounded Gauss limitedLinear 1;
}

laplacianSchemes
{
    default         Gauss linear limited 0.5;
}

snGradSchemes
{
    default         limited 0.5;
}

interpolationSchemes
{
    default         linear;
}

wallDist
{
    method meshWave;
}

fvSolution:
Code:
solvers
{
    p
    {
        solver                      GAMG;
        tolerance                   1e-8;
        relTol                      0.01;
        smoother                    GaussSeidel;
        nCellsInCoarsestLevel       1;
        minIter                     4;
        maxIter                     100;

    }

    U
    {
        solver          PBiCGStab;
        preconditioner  DILU;
        // nSweeps         2;
        tolerance       1e-8;
        relTol          0.0;
        minIter         4;
        maxIter         100;
    }

    k
    {
        solver          PBiCGStab;
        preconditioner  DILU;
        // nSweeps         2;
        tolerance       1e-8;
        relTol          0.0;
        minIter         4;
        maxIter         100;
    }

    omega
    {
        solver          PBiCGStab;
        preconditioner  DILU;
        // nSweeps         2;
        tolerance       1e-8;
        relTol          0.0;
        minIter         4;
        maxIter         100;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 2;
    pRefCell                 0;
    pRefValue                0;

    residualControl
    {
            p                   1e-4;
            U                   1e-4;
            "(k|omega|epsilon)" 1e-4;
    }
}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        default         0.9;
        U               0.5;
        k               0.9;
        omega           0.9;
        epsilon         0.9;
    }
}
i will apreciate any comment and help
thanks
Attached Images
File Type: png pressuregrdient.png (7.0 KB, 13 views)
File Type: png flowRate.png (7.5 KB, 13 views)
File Type: png residuals.png (9.8 KB, 16 views)

Last edited by Abonfil04; August 24, 2023 at 13:48.
Abonfil04 is offline   Reply With Quote

Old   October 20, 2023, 09:56
Default
  #2
Member
 
Pedro Gouveia
Join Date: Oct 2022
Location: Portugal
Posts: 63
Rep Power: 3
unilord is on a distinguished road
Hey,

Have you already found an answer to your problem? I am currently working in a centrifugal pump and the residuals I am getting are really close to yours.
unilord is offline   Reply With Quote

Reply

Tags
centrifugal pump, incompressible flow, openfaom

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



All times are GMT -4. The time now is 04:33.