Manual for LAGC V0.4

Purpose

LAGC is a multidimensional continuum mechanics code for time-dependent problems, solving the Lagrangian version of the dynamical equations. The code is written in C++.

Input

All input is ASCII and read from the standard input stream. 

verbosity (0:low)
number_of_dimensions (1/2/3)
spatial_metric (Realfunctionnd, e.g. 1dproduct 2 constant 1.0 constant 1.0 for 2D planar)

number_of_materials
For each:
   name
   material_data (mat_type)

number_of_graphics_specifications
For each:
   x_pixels y_pixels
   auto_flag (0: inline / 1: graphics_data_files)
   wx1 wx2 wy1 wy2 (fractional range of window to use)
   sx1 sx2 sy1 sy2 (corresponding range of "real" parameter)
   fred fgreen fblue (foreground colour)
   bred bgreen bblue (background colour)
   output_file_stem first_dump_index
   number_of_plot_objects (drawn in the order they are specified)
   For each:
      type parameters (see below)
   pause_after_flag (0/1: yes/no)
   clear_before_flag (0/1: yes/no)

Repeated until command is "end":
command parameters (see below)

Notes:

  1. Realfunctionnd is the maths class library type.
  2. mat_type is the ARIADNE class library type.

Plot specifications

Mesh lines: type mesh

red green blue (colour)
xoffset yoffset (offset of this plot in subject units of window)

Grain boundaries: type boundary

red green blue (colour)
xoffset yoffset (offset of this plot in subject units of window)

Scalar field, colormap: type scalar_field_colored

Parameters: 
parameter_name (pressure / mass_density / temperature / divu / csqv / velocity_x / velocity_y / velocity_z / artificial_viscosity / material / region / grain)
colormap_type (thermal / greyscale / spectral)
vmin vmax (map range)
number_of_colors
xoffset yoffset (offset of this plot in subject units of window)

Vector field, arrows: type vector_field

Parameters: 
parameter_name (velocity)
scale_vector
red green blue (colour)
head_length head_angle
xoffset yoffset (offset of this plot in subject units of window)

Commands

Generate new mesh: generate

Subsequent input: 
dump_file

For each dimension:
   Dxi dxi (spatial extent, zone size)

origin_vector

node_position_perturbation_amplitude

If >1D: mesh_type (rectilinear / triangulated / tetrahedral)

number_of_foreground_regions
For each:
   name type parameters (see below)

number_of_detonics_regions
For each:

boundary_accuracy
number_of_velocity_constraints
For each:
   type parameters:
      applied
         enclosing_surface (Surface)
         amplitude (Realfunction1d of time)
         orientation_vector
      normal
         enclosing_surface (Surface)
         amplitude (Realfunction1d of time)
      translation
         enclosing_surface (Surface)
         translation_vector
number_of_stress_constraints
For each:
   type parameters:
      applied
         enclosing_surface (Surface)
         pressure (Realfunction1d of time)
         deviatoric stress components (each Realfunction1d of time)
            s11 s22 s33 s23 s31 s12
      mirror
         enclosing_surface (Surface)
      translation
         enclosing_surface (Surface)
         translation_vector
number_of_propellors
For each:
   enclosing_surface (Surface)
   orientation_vector
   pressure (Realfunction1d of magnitude of velocity)
number_of_material_sources
For each:
   location velocity material_name material_state amplitude (Realfunction1d of time)
number_of_heat_sources
For each:
   location heating_rate (power / volume)
number_of_detonics_sources
For each:
   location time
number_of_detonics_inert_boundary_nodes
For each:
   node_index inner_node_index

How to define a location: location_type_name parameters 

Either:
   index cell_or_node_index
Or:
   nearest_position position_vector
Or:
   region surface (Surface type)

Read mesh from file: read

Subsequent input: 
dump_file

Integrate continuum equations in time: integrate

Subsequent input: 
dump_file

Courant_factor divergence_factor artificial_viscosity_factor evolution_factor detonation_factor (timestep safety factors)

qquad qlin (artificial viscosity parameters)

q_evolution_cutoff (max q/p for evolution to be allowed)
evolution_update_mode (1/2 for once/twice per time step)

initial_timestep growth_factor
min_timestep min_timestep_action (set / abort)
max_timestep max_timestep_action (set / abort)

eps_min eps_max (general small and large numerical cutoffs)

imaginary_sound_treatment (raw / abs)

detonics_flag (0/1 for off/on)
psi_store_u trigger_delay psi_trigger_disable
psi_wake psi_dead

start_time end_time max_timesteps

number_of_stop_sensors
For each:
   location parameter comparison value

dump_frequency dump_filename_stem first_dump_index
node_plot_interval node_plot_filename_stem first_node_plot_index
cell_plot_interval cell_plot_filename_stem first_cell_plot_index
shock_location_file artificial_viscosity_sensitivity
graphics_time_interval
number_of_history_files
For each:

Rezone mesh: rezone

Subsequent input: 
dump_file

Contents of dump file: 

background_node_array
background_cell_array

position_offset_vector
velocity_offset_vector
enclosing_surface (Surface)

number_of_foreground_regions
For each:
   node_array
   cell_array
   enclosing_surface
   position_offset_vector
   velocity_offset_vector

Supporting software

Libraries: