Constant mass flow rate in channel flow LES

vishwesh · May 10, 2018, 03:29

Hi!
I am trying to simulate channel flow simulation in OpenFOAM for constant mass flow rate. I found a test case for channel flow which uses a

Code:

momentumSource

in

Code:

fvOptions

file:

Code:

momentumSource
{
    type            pressureGradientExplicitSource;
    active          on;            //on/off switch
    selectionMode   all;       //cellSet // points //cellZone

    pressureGradientExplicitSourceCoeffs
    {
        fieldNames  (U);
        Ubar        ( 0.1335 0 0 );
    }
}

How can we use constant mass flow rate in Channel flow case? The test case can be found here.

Thanks in advance
Vishwesh

RobertHB · May 10, 2018, 04:12

Quote:

Originally Posted by vishwesh

Hi!
I am trying to simulate channel flow simulation in OpenFOAM for constant mass flow rate. I found a test case for channel flow which uses a

Code:

momentumSource

in

Code:

fvOptions

file:

Code:

momentumSource
{
    type            pressureGradientExplicitSource;
    active          on;            //on/off switch
    selectionMode   all;       //cellSet // points //cellZone

    pressureGradientExplicitSourceCoeffs
    {
        fieldNames  (U);
        Ubar        ( 0.1335 0 0 );
    }
}

How can we use constant mass flow rate in Channel flow case? The test case can be found here.

Thanks in advance
Vishwesh

Why not use the fvOptions entry you've found?

vishwesh · May 10, 2018, 04:15

I actually want to make changes in the geometry and see the affect it has on the wallShearStress and I thought it would be easier to use constant mass flow rate for the analysis rather than the constant pressure.

RobertHB · May 10, 2018, 04:30

Quote:

Originally Posted by vishwesh

I actually want to make changes in the geometry and see the affect it has on the wallShearStress and I thought it would be easier to use constant mass flow rate for the analysis rather than the constant pressure.

Ah okay. You can take a look at the other possible fvOptions entries. Maybe you find something you can use. Possible sources are explained on this website: http://www.geocities.jp/penguinitis2...fvOptions.html
Just use google chrome or google translate on the website

Santiago · May 10, 2018, 10:10

Quote:

Originally Posted by vishwesh

I actually want to make changes in the geometry and see the affect it has on the wallShearStress and I thought it would be easier to use constant mass flow rate for the analysis rather than the constant pressure.

Although a bit incidental to the discussion, I'm curious to know how does using a constant mass fliw rate make the analysis easier? I mean, i would expect that by virtue of Newton's second law it'd be easier to analyse and balance shear stress with pressure gradients

May 10, 2018, 03:29	Constant mass flow rate in channel flow LES	#1
vishwesh Member Vishwesh Ravi Shrimali Join Date: Aug 2017 Posts: 43 Rep Power: 9	Hi! I am trying to simulate channel flow simulation in OpenFOAM for constant mass flow rate. I found a test case for channel flow which uses a Code: momentumSource in Code: fvOptions file: Code: momentumSource { type pressureGradientExplicitSource; active on; //on/off switch selectionMode all; //cellSet // points //cellZone pressureGradientExplicitSourceCoeffs { fieldNames (U); Ubar ( 0.1335 0 0 ); } } How can we use constant mass flow rate in Channel flow case? The test case can be found here. Thanks in advance Vishwesh

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May 10, 2018, 04:15		#3
vishwesh Member Vishwesh Ravi Shrimali Join Date: Aug 2017 Posts: 43 Rep Power: 9	I actually want to make changes in the geometry and see the affect it has on the wallShearStress and I thought it would be easier to use constant mass flow rate for the analysis rather than the constant pressure.