Wall and Sheath

Collaboration diagram for Wall and Sheath:

Functions
static TokamakMagneticField	dg::geo::createModifiedField (dg::file::WrappedJsonValue gs, dg::file::WrappedJsonValue jsmod, CylindricalFunctor &wall, CylindricalFunctor &transition)
	Modify Magnetic Field and create wall above or below certain Psi values according to given parameters. More...
static CylindricalFunctor	dg::geo::createWallRegion (dg::file::WrappedJsonValue gs, dg::file::WrappedJsonValue jsmod)
	A convenience function call for dg::geo::createModifiedField that ignores the transition parameter and returns the wall. More...
static void	dg::geo::createSheathRegion (dg::file::WrappedJsonValue jsmod, TokamakMagneticField mag, CylindricalFunctor wall, dg::Grid2d &sheath_walls, CylindricalFunctor &sheath)
	Create the sheath region where fieldlines intersect the boundary. More...

Detailed Description

Function Documentation

createModifiedField()

static TokamakMagneticField dg::geo::createModifiedField ( dg::file::WrappedJsonValue  gs, dg::file::WrappedJsonValue  jsmod, CylindricalFunctor &  wall, CylindricalFunctor &  transition  )

inlinestatic

Modify Magnetic Field and create wall above or below certain Psi values according to given parameters.

We modify psi above or below certain Psip values to a constant using the dg::IPolynomialHeaviside function (an approximation to the integrated Heaviside function with width alpha), i.e. we replace psi with IPolynomialHeaviside(psi). This subsequently modifies all derivatives of psi and the poloidal current in this region.

Furthermore, the same parameters define the wall region.

{
    "type": "none"
}
{
    "type": "heaviside",
    "boundary": 1.1,
    "alpha": 0.20
}
{
    "type": "sol_pfr",
    "boundary": [1.1,0.998],
    // First value indicates SOL, second the PFR
    "alpha": [0.10,0.10]
}

See also

dg::geo::modification for possible values of "type" parameter

Parameters

gs	forwarded to dg::geo::createMagneticField
jsmod	contains the fields described above to steer the creation of the modification and wall region
wall	(out) On output contains the region where the wall is applied, the functor returns 1 where the wall is, 0 where there it is not and 0<f<1 in the transition region
transition	(out) On output contains the region where the transition of Psip to a constant value occurs, the functor returns 0<f<=1 for when there is a transition and 0 else

Returns

A magnetic field object

Attention

This function is only defined if json/json.h is included before dg/geometries/geometries.h

createSheathRegion()

static void dg::geo::createSheathRegion ( dg::file::WrappedJsonValue  jsmod, TokamakMagneticField  mag, CylindricalFunctor  wall, dg::Grid2d &  sheath_walls, CylindricalFunctor &  sheath  )

inlinestatic

Create the sheath region where fieldlines intersect the boundary.

The sheath functor that comes out of this does (i) on each of the four lines defined by the two vertical (R0, R1) and two horizontal (Z0, Z1) boundaries check if the "wall" functor is zero anywhere on the line: if not then move this boundary far away (ii) Measure the angular distance along the fieldline (both in positive and negative direction) to the remaining walls using dg::geo::WallFieldlineDistance (in "phi" mode) (iii) Modify the angular distances with a dg::PolynomialHeaviside functor with parameters given in jsmod:

{
    "boundary" : 0.0625, // value where sheath region begins in units of 2Pi
    "alpha" : 0.015625 // diameter of the transition region in units of 2Pi
}

(iv) The sheath region is the SetUnion of positive and negative functor, together with the SetIntersection with the SetNot(wall) region.

Parameters

jsmod	must contain fields as described above
mag	(in) the (unmodified) magnetic field, used to integrate the field towards or away from the sheath
wall	(in) the penalization region that represents the actual (perpendicular) wall without the divertor (if 0 on the boundary the boundary will be considered to be a sheath, else the boundary will be ignored)
sheath_walls	(inout) on input contains the box boundaries, on output the non-sheath boundaries are moved far away
sheath	(out) contains the region recognized as sheath (returning +1 within the sheath and 0 outside of it and something in-between in the transition region)

createWallRegion()

static CylindricalFunctor dg::geo::createWallRegion ( dg::file::WrappedJsonValue  gs, dg::file::WrappedJsonValue  jsmod  )

inlinestatic

A convenience function call for dg::geo::createModifiedField that ignores the transition parameter and returns the wall.