First-Type Heat

A first-type (Dirichlet, or temperature type) boundary condition is used when the temperature along the boundary is specified. Note that this type of boundary condition is generally not mass conservative. We recommend users to invoke third-type boundary conditions where possible since this condition is physically more realistic and preserves heat mass in the simulated system (e.g., van Genuchten and Parker, 1984; Leij et al., 1991).

See also the "How to Edit Boundary Conditions" topic.