nLight AFX Heat Source

The SS316L case uses the ORNL-characterized nLight AFX Index 6 profile with a projected heat source and exponential axial projection.

SS316L top-surface temperature for the nLight AFX profile. The black and white contours denote the 1471 K solidus and 1709 K liquidus, respectively.

Physical setup

• SS316L properties from $ADDITIVEFOAM_ETC/materials/SS316L.cfg.
• One projected heat source with an nLightAFX planar profile.
• Seven characterized beam modes, Index0 through Index6; the tutorial selects Index6.
• An exponential axial projection with configured depth 20 µm.
• A liquidus reference depth; the configured depth is the minimum applied depth.
• Eight MPI ranks.

Run

cp -r "$ADDITIVEFOAM_TUTORIALS/nLightAFX" "$FOAM_RUN/nLightAFX"
cd "$FOAM_RUN/nLightAFX"
./Allrun

Important inputs

File	Purpose
$ADDITIVEFOAM_ETC/heatSources/nLightAFX-1000.cfg	Shared definitions for characterized modes Index0 through Index6
constant/heatSourceDict	Profile, projection, absorption, integration, and AMR settings
constant/scanPath	Beam position, time, and power
constant/transportProperties	Includes the SS316L material properties
system/decomposeParDict	Eight-rank domain decomposition
system/controlDict	Run controls and optional Function Objects

Workflow

The heat-source dictionary includes the shared mode definitions and selects one inside the nested profile dictionary:

#include "$ADDITIVEFOAM_ETC/heatSources/nLightAFX-1000.cfg"

sources
{
    beam
    {
        path            scanPath;
        widthReference  D4Sigma;
        depthReference  isotherm;

        absorption
        {
            model   constant;
            eta     0.33;
        }

        heatSource
        {
            model       projected;
            depth       20.0e-6;
            nPoints     (10 10 10);

            profile
            {
                model   nLightAFX;
                $Index6;
            }

            projection
            {
                model       exponential;
                nSlope      0.0;
                nIntercept  1.0;
            }
        }
    }
}

Change only $Index6 to $Index0, $Index1, …, or $Index5 to select another characterized mode.

Each index supplies:

alpha
r0
sigma0
r1
sigma1

r0, sigma0, r1, and sigma1 are metres. alpha is the integrated power fraction assigned to the outer ring. The tutorial uses nSlope 0, nIntercept 1, and the area-equivalent D4Sigma width. See Heat Source Models for the profile and projection equations.

Outputs

Open the reconstructed case in ParaView and visualize T, alpha.solid, and qDot to compare the selected ring profile with its temperature and phase response.

Absorbed power, melt-pool dimensions, solidification data, and ExaCA histories are covered by the baseline output workflows.