forceSubModel: scaleDragByFieldFunction

Syntax

Defined in couplingProperties sub-dictionary of the force model in use.

forceModels
(
    XYZDrag
);
XYZDragProps
{
    fieldName "word1";
    forceSubModels
    (
        scaleDragByFieldFunction
    );

    functionOfField table
    (
        (0      1)
        (1      2)
    );
};

  • word1 = name of the field used for scaling the drag coefficient (optional, default: “voidfraction”)

Examples

forceModels
(
    KochHillDrag
);
KochHillDragProps
{
    forceSubModels
    (
        scaleDragByFieldFunction
    );

    functionOfField table
    (
        (0      1)
        (0.5    1)
        (1      2)
    );
}

Description

This forceSubModel performs a drag correction in the form of C_{d,c} = C_{d} \beta, where C_{d} is the original drag coefficient as defined by the drag model, C_{d,c} is the corrected one, and \beta = \beta(f_p) is a function of the generic field f_p = f(\vec{x}_p,t) evaluated at the particle location \vec{x}_p. If a field is not specified via the keyword fieldName, then f is set equal to the voidfraction by default.

The function \beta(f_p) is defined in form of look-up table (see keyword functionOfField). The first value of each pair is f evaluated at the center of the cell containing the particle and the second is \beta(f_p). A linear interpolation is used to calculate \beta for other values of f_p.

Restrictions

None.