Problem Description
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This section directs all input specifications required for differential equations, material type, mesh motion type, coordinate system, finite element basis function type, and several other input tasks. This section of input records, with the exception of the *Number of Materials* card (the first one
below), must be repeated for each material region in the problem. Within that region of the problem domain (and the corresponding section of the input file) there are no restrictions as to which differential or constraint equations can be specified, which is a unique capability of *Goma*.
However, some combinations or specifications do not make much sense, e.g., a cylindrical coordinate region combined with a cartesian one. It is recommended that the user consult the usage tutorials and example problems to get a feel for how this section is constructed.
.. toctree::
:maxdepth: 1
problem_description/number_of_materials
problem_description/mat
problem_description/coordinate_system
problem_description/element_mapping
problem_description/mesh_motion
problem_description/number_of_bulk_species
problem_description/material_is_nondilute
problem_description/number_of_bulk_species_equations
problem_description/default_material_species_type
problem_description/number_of_viscoelastic_modes
problem_description/number_of_matrices
problem_description/matrix
problem_description/disable_time_step_control
problem_description/normalized_residual_tolerance
problem_description/number_of_eq
problem_description/energy
problem_description/momentum
problem_description/pmomentum
problem_description/stress
problem_description/eddy_visc
problem_description/species_bulk
problem_description/mesh
problem_description/mom_solid
problem_description/continuity
problem_description/fill
problem_description/lagr_mult_1_lagr_mult_2_lagr_mult_3
problem_description/level_set
problem_description/voltage
problem_description/efield
problem_description/enorm
problem_description/shear_rate
problem_description/vort_dir
problem_description/vort_lambda
problem_description/porous_sat
problem_description/porous_unsat
problem_description/porous_liq
problem_description/porous_gas
problem_description/porous_deform
problem_description/porous_energy
problem_description/surf_charge
problem_description/shell_tension
problem_description/shell_curvature
problem_description/shell_angle
problem_description/shell_diff_flux
problem_description/shell_diff_curv
problem_description/shell_normal
problem_description/shell_surf_curv
problem_description/shell_surf_div_v
problem_description/grad_v_dot_n1_grad_v_dot_n2_grad_v_dot_n3
problem_description/n_dot_curl_v
problem_description/acous_preal
problem_description/acous_pimag
problem_description/acous_reyn_stress
problem_description/potential1
problem_description/potential2
problem_description/lubp
problem_description/lubp_2
problem_description/shell_energy
problem_description/shell_filmp
problem_description/shell_filmh
problem_description/shell_partc
problem_description/shell_sat_closed
problem_description/shell_sat_gasn
problem_description/shell_sat_open
problem_description/shell_sat_open_2
problem_description/shell_deltah
problem_description/moment
problem_description/end_of_eq
problem_description/end_of_mat