[JuanRodriguez]

Hi.

I have read already Anton Persson's report describing dieselFoam. I have noticed this solver and sprayFoam have many differences.

Is there a description/report of sprayFoam>

I ask this becuase I dont know what does Constant Properties in sprayCloudProperties refer to. Also, I wan to know how to set the spray injection temperature and pressure. I know in 0/T or 0/p one can set boundary conditions for these scalars but for the general duct where the spray takes place (the mass of air, for example)

Thank you

[mturcios777]

You can set the spray temperature (stagnation temperature) in T0. If you want a pressure driven flow in the spray you need to select a coneNozzleInjector as the type, and flowType as pressureDrivenVelocity. You will need a keyword called Pinj which is the injection pressure.

[JuanRodriguez]

Hi Marcos,

Do you know what parameter describes liquid evaporation? I used Y(component)l in paraview but its scale was from 1 to 2, which seems odd, does not it? If it is not odd at all, then what does it mean?

By the way, I am having trouble setting the BC to get an inner flow of air. Could you please give me some guide with respect to this?

Thank you.

[mturcios777]

What do you mean by the liquid evaporation? The species fractions, parcel mass, etc? Ycomponent is the index of the species in the parcel, my guess is you have 3 species?

[JuanRodriguez]

Hi Marco,
Oh, I see. Yes indeed, I am working with three species (N2, O2 and Water).
My question regarding liquid evaporation was if there exists a variable in OF that represents a vapor fraction of the sprayed species, or that contains information about phase change.

Thank you, Marco.

[mturcios777]

For lagrangian spray models, diameter would give you some indication of evaporation. The vapour fraction of sprayed species would be the species fraction in the continuous phase I would think. When you plot H2O it should show it increasing where the droplets are evaporating.

[JuanRodriguez]

Thank you, Marco.
I will follow your recommendation.

[JuanRodriguez]

I am investigating how sprayFoam works. And I have seen that inside the solver folder there are only pEqn.H, rhoEqn.h and UEqn.H, but sprayFoam.C uses also YEqn.H and EEqn.H. My question is where does sprayFoam.C load them from?

Thanks.

[wolfindark]

Originally Posted by JuanRodriguez

I am investigating how sprayFoam works. And I have seen that inside the solver folder there are only pEqn.H, rhoEqn.h and UEqn.H, but sprayFoam.C uses also YEqn.H and EEqn.H. My question is where does sprayFoam.C load them from?

Thanks.

I think It uses the ones reactingParcelFoam. Please check it...

[JuanRodriguez]

I also have that intuition, Neilson. But I don't know how to confirm it.
Anyway, sprayFoam seems to calculate at each iteration these three measures, D32, D10, and Dmax. Other solvers, like reactingParcelFoam don't. How can I register these values with that solver? Is it possible?

Thanks/

[Likun]

Neilson is correct. If you check ''sprayFoam.dep", you will find

sprayFoam.dep: ../reactingParcelFoam/YEqn.H
sprayFoam.dep: ../reactingParcelFoam/EEqn.H

which show that sprayFoam uses YEqn.H and EEqn.H from reactingParcelFoam.

Best,
Likun

[heruitian]

Hi,
I am trying to simulate the n-dodecane evaporation based on sprayFoam in OF. With the C12H26 file in each time documents, I define the vapor penetration just like the definition in other commercial software. But the vapor penetration is shorter than the liquid penetration in the initial time. It's unacceptable in the experiments. I wonder if there is mistakes in vapor penetration definition or the setting values, such as KHRT parameters in OF,which can let the droplet evaporate faster in the initial time?
Thank you!

[Rid@foam]

Hello everyone.
I am simulating a case in sprayFoam and I want to keep an atmospheric pressure boundary condition to the outlet of the domain.
What value should I give for this?
Should I give 0 Pa(i.e. the gauge pressure) or should I give 1e5 Pa(i.e. the absolute pressure)?
Anyone please help me as I am new to sprayFoam solver and do not understand it well.

[mm66]

Dear Foamers,

I am trying to simulate a pure pressure driven flow through a nozzle using speayFoam in OpenFoam1812. I would like to obtain the mass flow rate through the nozzle. Here is the relevant info from sprayCloudProperties file:

    injectionModels
    {
        model1
        {
            type            coneNozzleInjection;
            SOI             0;
            massTotal       1e-5;
            parcelBasisType mass;
            injectionMethod disc;
            flowType        pressureDrivenVelocity;
            Pinj	    constant 1e6;
            outerDiameter   2e-4;
            innerDiameter   0;
            duration        50e-3;
            position        (0 0.5 0);
            direction       (0 -1 0);
            parcelsPerSecond 20000000;
            flowRateProfile constant 1;

The problem is that (to my knowledge) both "massTotal" and "duration" should be defined. Consequently, wouldn't the mass flow rate be imposed to the domain as mass flow = "massTotal" / "duration"?

I really appreciate your thoughts on this.

Regards,
MJ

[mm66]

Originally Posted by Rid@foam

Hello everyone.
I am simulating a case in sprayFoam and I want to keep an atmospheric pressure boundary condition to the outlet of the domain.
What value should I give for this?
Should I give 0 Pa(i.e. the gauge pressure) or should I give 1e5 Pa(i.e. the absolute pressure)?
Anyone please help me as I am new to sprayFoam solver and do not understand it well.

Dear Riddhideep,

I believe you should use the absolute pressure (something like the following):

dimensions          [1 -1 -2 0 0 0 0];

internalField       uniform 1e06;

boundaryField
{
    walls
    {
        type            zeroGradient;
    }
    outlet
    {
        type            fixedValue;
        value           uniform 1e06;
    }
}

Hope this helps

Cheers,
MJ

[FluentStarter]

Originally Posted by mm66

Dear Foamers,

I am trying to simulate a pure pressure driven flow through a nozzle using speayFoam in OpenFoam1812. I would like to obtain the mass flow rate through the nozzle. Here is the relevant info from sprayCloudProperties file:

    injectionModels
    {
        model1
        {
            type            coneNozzleInjection;
            SOI             0;
            massTotal       1e-5;
            parcelBasisType mass;
            injectionMethod disc;
            flowType        pressureDrivenVelocity;
            Pinj	    constant 1e6;
            outerDiameter   2e-4;
            innerDiameter   0;
            duration        50e-3;
            position        (0 0.5 0);
            direction       (0 -1 0);
            parcelsPerSecond 20000000;
            flowRateProfile constant 1;

The problem is that (to my knowledge) both "massTotal" and "duration" should be defined. Consequently, wouldn't the mass flow rate be imposed to the domain as mass flow = "massTotal" / "duration"?

I really appreciate your thoughts on this.

Regards,
MJ

Did you manage to answer this question?

[Mingyang]

Dear Foamers,

In the calculation example of sprayFoam delivered with OpenFoam, the working medium is hydrocarbon C7H16. I want to use this calculation example to adapt the working medium to liquid NH3 for numerical simulation, observation and study of its spray effect. At present, the first step is to know how to convert the spray working medium in the tutorials.I uploaded my case files to the git hub,https://github.com/Fancy2121/sprayfo...m/aachenBomb,I would appreciate some advice.