For a more comprehensive introduction look at the Goma Capabilities document (PDF, August 2020)
Goma 6.0 is software for numerical simulation of multiphysics continuum processes, including moving geometry, phase-change, fluid-structural interactions, complex rheology, and chemical reactions. It solves the fundamental equations of mass, momentum, energy, and chemical species transport using the finite-element method
Goma 6.0 solves problems from all branches of mechanics, including fluid mechanics, solid mechanics, chemical reactions and mass transport, and energy transport. The conservation principles for momentum, mass, species, and energy, together with material constitutive relations, can be described by partial differential equations. The equations are made discrete for solution on a digital computer with the finite element method in space and the finite difference method in time. The resulting nonlinear, time-dependent, algebraic equations are solved with a full Newton-Raphson method. The linearized equations are solved with direct or Krylov-based iterative solvers. The simulations can be run on a single processor or on multiple processors in parallel using domain decomposition, which can greatly speed up engineering analysis
Goma is designed as a general mechanics code, with no features that tie it to any particular application. Applications, or problems to be solved, are specified completely in input files, which include code and material properties specifications. The multitude of differential equations, material constitutive equations, and boundary conditions has evolved with the applications, but they are all from theories fully published in the open literature and Goma’s theory manual.
Although many of Goma’s applications involve fixed boundaries, Goma really stands out when applied to problems with dynamic geometries, i.e. free and moving boundaries. A novel algorithm for mesh motion is at the heart of Goma, where boundary motion is accommodated by allowing mesh nodes to move as if they were a pseudo-solid rubbery material. This is where Goma gets its name, which means “rubber elasticity” in Spanish. From the principles of kinematics, this algorithm can be applied to either fluid- or solid-material regions or to problems of fluid-structure interactions. The problem can be Lagrangian, meaning that the mesh moves with the material, or Arbitrary Lagrangian Eulerian, meaning that in some places the mesh moves with the material and in others it does not. Goma 6.0 also includes purely Eulerian boundary tracking methods on stationary meshes, using either the level set or the overset-grid methods.
Goma's capability is based on customer need
Mechanics — Includes all major branches of mechanics and more. Conjugate capability.
Material models and constitutive equations — Includes generalized Newtonian and VE for fluids, elastic and elastoviscoplastic for solids, Fickian, multicomponent, and non-Fickian fluxes, and more
Free surface and free boundary tracking — Solidification surfaces, capillary free surfaces, consolidation fronts, mold filling fronts, saturation fronts, user prescribed kinematics and geometry, ablation fronts, and more
Multidimensional with 2.5D capability. Full shell capability.
Platform generality — High-end, high-performance, and commodity hardware
User prescribed and user defined capability
Fluid-structural interactions — Computational Lagrangian solids and ale in both solids and fluids with Eulerian-Eulerian methods an active research area
Saturated and unsaturated, deformable, porous media — Poro-elastic and poro-plastic
Full-Newton coupled algorithms and automated continuation, augmenting conditions, stability analysis — All in a production setting
Other advanced features — Shell reduced order models, solid-model-based geometry support; advanced post processing features
Pixel and Voxel-to-mesh capability
Generalized Newtonian (concentration, temperature and shear-rate dependence). Carreau, Carreau-WLF, Molten glass, epoxy, epoxy cure, bingham-plastic
Industry applications: Extrusion, polymer processing, coating
Supension balance models (Phillips model for particle concentration, Krieger for viscosity)
Industry applications: Multiphase manufacturing flows
Single or multimode viscoelastic with EVSS split stress approach
Industry applications: Extrusion, polymer processing, coating
Vapor/liquid equilibrium - Ideal and Flory Huggins
Discontinous variables approach for interphase mass-momentum transport (Schunk and Rao, IJNMF 1994)
Vapor-pressur VS (T, C, K) models, Viz. Kelvin equation, Riedel, Antoine, etc.
Liquid and solid equilibrium - Scheil or solute dependent solidification (latent heat release with enthalpy or intefacial Stephan condition).
Liquid andSolid macrosegregation with Flemings-Mehrabian model
Polymer thermoset and condensation curing
Shell Element Technology can be easily integrated into a large-aspect-ratio structure (shell elements can be membranes, inextensible shell, lubrication, or porous)
Goma 6.0 has integrated true curvilinear shell capability for lubrication (the first of its kind to our knowledge with continuum codes), porous, penetration, and integrated structure
Comprehensive mechanics couplings allow the algorithms to run with minimal tuning
Advanced, automated machinery allows for complex algorithms (augmenting condition capability, linear stability, and high-order continuation)
Advanced, automated machinery allows for complex algorithms (augmenting condition capability, linear stability, and high-order continuation) and faster quadratic convergence
Augmenting conditions (volume, mesh constrains, optimization) allows extreme analysis precision
ARPACK and Eggroll provide linear stability analysis in both 2D and 3D dynamic systems