Multi-Beam

This case extends AMB2018-02-B to two simultaneous beams. Both have the calibrated single-track power, speed, absorption, and source dimensions, and their paths are translated by ±50 µm in the hatch direction.

IN625 top-surface temperature during simultaneous scanning by two heat sources. The black and white contours denote the 1410 K solidus and 1620 K liquidus, respectively.

Physical setup

  • IN625 properties from $ADDITIVEFOAM_ETC/materials/IN625.cfg.
  • Two simultaneous superGaussian heat sources.
  • Independent paths separated by 100 µm in the hatch direction.
  • Fluid flow disabled by nOuterCorrectors 0 in the supplied case.

The heat-source list is:

sources (beam1 beam2);

Run 

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

Important inputs

File Purpose
constant/heatSourceDict Defines beam1, beam2, their models, and source-specific AMR buffers
constant/scanPath_1 Position, time, and power for beam1
constant/scanPath_2 Position, time, and power for beam2
constant/dynamicMeshDict OpenFOAM topology changer
system/controlDict Run controls and optional Function Objects
system/fvSolution Flow, temperature, and phase-coupling controls

Workflow

Allrun generates the mesh, decomposes the case, runs additiveFoam in parallel, and reconstructs the fields. Each source reads its own scan path and coefficient dictionary. Source-list order does not define firing order; the time and power columns in each scan path determine when a beam is active.

When both beams are active, the volumetric source field is

\[q_{\mathrm{dot}}(\mathbf{x},t) =q_1(\mathbf{x},t)+q_2(\mathbf{x},t),\]

where $q_1$ and $q_2$ are the absorbed volumetric power densities of beam1 and beam2, respectively. The absorbed-power value reported in the solver log is the volume integral of this combined field.

Outputs

Open the reconstructed case in ParaView and visualize T, alpha.solid, and qDot to inspect the interaction between the two moving sources and their melt pools.

The baseline case documents the common quantitative and microstructure output workflows: