mp-radiative-transport: Parameter description

Contents

• base

• time stepping

• adaptive meshing

• rte

• laser

• output

• profiling

---

🔷 base

Parameter	Type	Default	Description
case name	string	not_initialized	Sets the base name for the application that will be fed to the problem type.
dimension	integer	2	Defines the dimension of the problem
number	string	double	Floating point number format. Currently, only ‘double’ is explicitely instantiated. Allowed values: - double
global refinements	integer	1	Defines the number of initial global refinements
do print parameters	boolean	True	Set this parameter to true to list parameters in output
verbosity level	integer	1	Sets the verbosity level of the console output: 0: silent: for non-robust tests and benchmark runs; 1: minimal: for robust tests; 2: detailed; 3: full
fe	object		See table

base: fe

Parameter	Type	Default	Description
type	string	FE_Q	Finite Element.FE_Q: hexahedral continuous finite element with polynomial degree p; FE_SimplexP: tetrahedral continuous finite element with polynomial degree p; FE_Q_iso_Q1: hexahedral continuous finite element with p subdivisions containing linear elements; FE_DGQ: hexahedral discontinuous finite element with polynomial degree p Allowed values: - not_initialized - FE_Q - FE_SimplexP - FE_Q_iso_Q1 - FE_DGQ
degree	integer	1	Defines the degree p of the finite element type. If “type” is “FE_Q_iso_Q1” this parameter defines the number of subdivisions.

---

🔷 time stepping

Parameter	Type	Default	Description
start time	number	0.0	Defines the start time for the solution of the levelset problem
end time	number	1.0	Sets the end time for the solution of the levelset problem
time step size	number	0.01	Sets the step size for time stepping. For non-uniform time stepping, this parameter determines the size of the first time step.
max n steps	integer	10000000	Sets the maximum number of melt_pool steps
time step size function	string	0.0*t	Set an analytical function to determine the time step size. For the prediction of the new time increment, the old time is used.

---

🔷 adaptive meshing

Parameter	Type	Default	Description
do amr	boolean	False	Set this parameter to true to activate adaptive meshing
do not modify boundary cells	boolean	False	Set this parameter to true to not refine/coarsen along boundaries.
upper perc to refine	number	0.0	Defines the (upper) percentage of elements that should be refined
lower perc to coarsen	number	0.0	Defines the (lower) percentage of elements that should be coarsened
max grid refinement level	integer	12	Defines the number of maximum refinement steps one grid cell will be undergone.
min grid refinement level	integer	-1	Defines the number of minimum refinement steps one grid cell will be undergone.
n initial refinement cycles	integer	0	Defines the number of initial refinements.
every n step	integer	1	Defines at every nth step the amr should be performed.
min cells marked to refine	integer	1	Minimum number of cells that must be marked for refinement/coarsening before the mesh is updated.
min indicator threshold to refine cell	number	0.0	Minimum indicator value required for a cell to be considered for refinement.
solution transfer average values	boolean	False	Set this parameter to true to average the contribututions to the same DoF coming from different cells during solution transfer.

---

🔷 rte

Parameter	Type	Default	Description
fe	object		See table
rte verbosity level	integer	-1	Sets the maximum verbosity level of the console output. The maximum level with respect to the base value is decisive.
predictor type	string	none	Choose a predictor type. Allowed values: - none - pseudo_time_stepping
absorptivity type	string	gradient_based	Chooses the formulation of the absorptivity coefficient Allowed values: - constant - gradient_based
avoid singular matrix absorptivity	number	1e-16	Minimum value for absorptivity to ensure a non-singular matrix for RTE.
linear solver	object		See table
pseudo time stepping	object		See table
absorptivity	object		See table

rte: fe

Parameter	Type	Default	Description
type	string	not_initialized	Finite Element.FE_Q: hexahedral continuous finite element with polynomial degree p; FE_SimplexP: tetrahedral continuous finite element with polynomial degree p; FE_Q_iso_Q1: hexahedral continuous finite element with p subdivisions containing linear elements; FE_DGQ: hexahedral discontinuous finite element with polynomial degree p Allowed values: - not_initialized - FE_Q - FE_SimplexP - FE_Q_iso_Q1 - FE_DGQ
degree	integer	-1	Defines the degree p of the finite element type. If “type” is “FE_Q_iso_Q1” this parameter defines the number of subdivisions.

rte: linear solver

Parameter	Type	Default	Description
solver type	string	GMRES	Set this parameter for choosing an iterative linear solver type. Allowed values: - CG - GMRES
preconditioner type	string	ILU	Set this parameter for choosing a preconditioner type. Allowed values: - Identity - AMG - ILU - Diagonal
max iterations	integer	10000	Set the maximum number of iterations for solving the linear system of equations.
rel tolerance	number	1e-12	Set the relative tolerance for a successful solution of the linear system of equations.
abs tolerance	number	1e-20	Set the absolute tolerance for a successful solution of the linear system of equations.
do matrix free	boolean	True	Set this parameter if a matrix free solution procedure should be performed.
monitor type	string	none	Set the monitor type of the linear solver. Allowed values: - none - reduced - all

rte: pseudo time stepping

Parameter	Type	Default	Description
diffusion term scaling	number	1.0	Scaling parameter of diffusion term.
advection term scaling	number	1.0	Scaling parameter of advection term.
pseudo time scaling	number	0.01	Determine the pseudo-time step as the product of this scaling and minimum cell size.
rel tolerance	number	0.001	Pseudo-time stepping relative tolerance.
time stepping	object		See table
linear solver	object		See table

rte: pseudo time stepping: time stepping

Parameter	Type	Default	Description
start time	number	0.0	Defines the start time for the solution of the levelset problem
end time	number	1.79769e+308	Sets the end time for the solution of the levelset problem
time step size	number	0.0	Sets the step size for time stepping. For non-uniform time stepping, this parameter determines the size of the first time step.
max n steps	integer	1	Sets the maximum number of melt_pool steps
time step size function	string	0.0*t	Set an analytical function to determine the time step size. For the prediction of the new time increment, the old time is used.

rte: pseudo time stepping: linear solver

Parameter	Type	Default	Description
solver type	string	CG	Set this parameter for choosing an iterative linear solver type. Allowed values: - CG - GMRES
preconditioner type	string	ILU	Set this parameter for choosing a preconditioner type. Allowed values: - Identity - AMG - ILU - Diagonal
max iterations	integer	10000	Set the maximum number of iterations for solving the linear system of equations.
rel tolerance	number	1e-12	Set the relative tolerance for a successful solution of the linear system of equations.
abs tolerance	number	1e-20	Set the absolute tolerance for a successful solution of the linear system of equations.
do matrix free	boolean	True	Set this parameter if a matrix free solution procedure should be performed.
monitor type	string	none	Set the monitor type of the linear solver. Allowed values: - none - reduced - all

rte: absorptivity

Parameter	Type	Default	Description
absorptivity gas	number	0.1	Sets the absorptivity of the gas phase.
absorptivity liquid	number	0.9	Sets the absorptivity of the liquid phase.
avoid div zero constant	number	1e-16	Sets the absorptivity of the gas phase.

---

🔷 laser

Parameter	Type	Default	Description
model	string	not_initialized	Laser model. analytical_temperature: see Mirkoohi et al. (2019); volumetric: volumetric heat source, the intensity is defined by “”intensity profile””; interface_projection: projection-based regularized continuum surface flux in “direction”, the intensity is defined by “”intensity profile””; interface_projection_sharp: projection-based sharp surface flux in “direction”, the intensity is defined by “”intensity profile””; interface_projection_sharp_conforming: projection-based sharp surface flux in “direction” on a conforming mesh, the intensity is defined by “”intensity profile””; RTE: continuum surface flux projected using the radiative transport equation in “direction”, supporting shadowing of undercuts, the intensity is defined by “”intensity profile””; Allowed values: - not_initialized - analytical_temperature - volumetric - interface_projection_regularized - interface_projection_sharp - interface_projection_sharp_conforming - RTE
intensity profile	string	Gauss	Laser intensity profile. uniform: note that the “power” input is treated as the uniform power density in the whole domain; Gauss: Gaussian laser intensity shape with “radius” that retains the “power”; Gusarov: see Gusarov et al. (2009); Allowed values: - uniform - Gauss - Gusarov
power	number	0.0	Laser power
power over time	string	constant	Temporal distribution of the laser power Allowed values: - constant - ramp
power start time	number	0.0	In case of time-dependent laser power: activation time of
power end time	number	1.79769e+308	In case of time-dependent laser power: end time of
absorptivity gas	number	1.0	Laser energy absorptivity of the gaseous part of the domain.
absorptivity liquid	number	1.0	Laser energy absorptivity of the liquid part of the domain.
starting position	string	``	Center coordinates of the laser beam starting position on the interface melt/gas.
scan speed	number	0.0	Scan speed of the laser
scan direction	string	``	Direction of laser motion as a vector
beam direction	string	``	Laser beam direction.
beam rotation axis	string	``	Axis around which the initial laser beam direction will be rotated. Relevant only in 3D.
beam rotation angle	number	0.0	Rotation angle applied to the laser beam direction (in 3D about ‘beam rotation axis’ following the right-hand rule; in 2D: as defined by the 2D rotation matrix
radius	number	0.0	Laser beam radius.
gusarov	object		See table
analytical	object		See table
dirac delta function approximation	object		See table

laser: gusarov

Parameter	Type	Default	Description
reflectivity	number	0.0	Reflectivity of the material.
extinction coefficient	number	0.0	Extinction coefficient in [1/m].
layer thickness	number	0.0	Layer thickness

laser: analytical

Parameter	Type	Default	Description
ambient temperature	number	0.0	Ambient temperature in the inert gas.
max temperature	number	0.0	Maximum temperature arising in the melt pool. If this temperature is lower than the boiling temperature, this value is corrected to correspond to the boiling temperature + 500 K.
temperature x to y ratio	number	1.0	This factor scales the analytical temperature field to be anisotropic.

laser: dirac delta function approximation

Parameter	Type	Default	Description
type	string	norm_of_indicator_gradient	Choose how to smear a parameter over the interface. Allowed values: - norm_of_indicator_gradient - heaviside_phase_weighted - heaviside_times_heaviside_phase_weighted - reciprocal_phase_weighted - reciprocal_times_heaviside_phase_weighted - heavy_phase_only
auto weights	boolean	False	Choose if weights should be computed automatically.
gas phase weight	number	1.0	If >>> dirac delta function approximation type <<< is set to any phase weighted optionthis parameter controls the (first) weight of the gas phase (level set = -1).
heavy phase weight	number	1.0	If >>> dirac delta function approximation type <<< is set to any phase weighted optionthis parameter controls the (first) weight of the heavy phase (level set = 1).
gas phase weight 2	number	1.0	If >>> dirac delta function approximation type <<< is set to >>> heaviside_times_heaviside_phase_weighted <<< this parameter controls the second weight of the gas phase (level set = -1).
heavy phase weight 2	number	1.0	If >>> dirac delta function approximation type <<< is set to >>> heaviside_times_heaviside_phase_weighted <<< this parameter controls the second weight of the heavy liquid/solid phase (level set = 1).

---

🔷 output

Parameter	Type	Default	Description
directory	string	./	Sets the base directory for all output.
write frequency	integer	1	Every n timestep that should be written
write time step size	number	1.79769e+308	Write output output every given time step. If this parameter is set, the output write frequency is deactivated.
output variables	string	all	Specify variables that you request to output.
do user defined postprocessing	boolean	False	Set this parameter to true to enable user defined postprocessing.
paraview	object		See table
particles	object		See table

output: paraview

Parameter	Type	Default	Description
enable	boolean	False	Set this parameter to true to activate paraview output.
filename	string	solution	Sets the base name for paraview output files.
n digits timestep	integer	4	Number of digits for the frame number of the vtu-file.
print boundary id	boolean	False	Set this parameter to true to output a vtu-file with the boundary id.
output subdomains	boolean	False	Set this parameter to true to output the subdomain ranks.
output material id	boolean	False	Set to true to output the material id.
write higher order cells	boolean	True	Set this parameter to false to write bi- or trilinear data only. Set this parameter to true to write higher order cell data. Note: higher order cell data can only be written for hexahedron meshes and 2 or 3 dimensions.
n groups	integer	1	Number of parallel written vtu-files.
n patches	integer	0	Control number of patches to enable high-order.

output: particles

Parameter	Type	Default	Description
enable	boolean	False	Set this parameter to true to activate particle paraview output.
filename	string	particle	Sets the base name for particle output files.

---

🔷 profiling

Parameter	Type	Default	Description
verbosity	string	none	Sets the verbosity of the profiling information to be collected. If set to ‘none’, no profiling information is collected. If set to ‘basic’, only data which is cheap to collect is recorded. If set to ‘detailed’, also data which is expensive to collect is recorded. It is recommended to enable detailed profiling only when necessary for in-depth analysis or debugging purposes. Allowed values: - none - basic - detailed
write time step size	number	10.0	Write profiling output every given time step size. If this parameter is set, the specified parameter for write frequency is overwritten.
time type	string	real	Choose the type of time measure to write profiling information. Allowed values: - real - simulation

---