Truchas is open source software developed by Los Alamos National Laboratory (LANL) and collaborators for physics-based modeling and simulation of manufacturing processes. Its core capabilities are primarily geared toward metal casting, with developing capabilities for additive manufacturing. It is, however, a general multi-physics computational tool that is useful for a wider range of applications.

Truchas includes coupled physics models for incompressible multi-material flow with interface tracking, heat transfer, phase change, view factor thermal radiation, species advection-diffusion, elastic/plastic mechanics with contact, and electromagnetics. It employs finite volume, finite element, and mimetic finite difference discretizations on 3-D unstructured meshes composed of mixed cell types.