[ajithnair]

Hi Foamers


How can we provide an ignition source in combustion which lasts for only few seconds till the charge ignites.

I have tried setting high temperature for internal field but the flame just ignites on entry itself. Is there a way to give high temperature patch?

[PaleliSooraj]

You can use a volumetric heat source for creating high temperature patch using fvOptions or setFieldsDict. Time of ignition can be mentioned there.

[überschwupper]

As an example:


fvModels (since OFv9 )

ignition
{
    type             heatSource;//semiImplicitSource;
    selectionMode    cellSet;
    cellSet            ignition;
    volumeMode        absolute; //absolute

    q 
    {
        type scale;
        scale squarePulse;
        start 0.0005;
        duration 0.001;
        value 1e+8;
    }
    /*sources
    {
        Qign
        {
            // type             semiImplicitSource;
            // name             heatInjection;
            // selectionMode     cellSet;
            // cellSet         ignition;
            // volumeMode        specific;
            // timeStart        0.001;
            // duration        0.01;
            explicit 10e+7;
            implicit 0; //{}
        }
    }*/
}

and topoSetDict

actions
(
    {
        name ignition;//ignitionCells;
        type cellSet;
        action new;

        source cylinderToCell; // or whatever
        sourceInfo
        {
            p1          (x y z);
            p2            (x y z);
            radius          1e-2; //outer radius
            innerRadius        0;    //default 0
        }
    }
);

[ajithnair]

Thankyou. the volumetric heat source idea worked. It was given using fvModels.(i am using openfoam dev, ofv9 should also have this. earlier versions it was under a file called fvOptions)