DirichletCondition
DirichletCondition[beqn, pred] represents a Dirichlet boundary condition given by equation beqn, satisfied on the part of the boundary of the region given to NDSolve and related functions where pred is True.
Examples
Set a Dirichlet boundary condition:
DirichletCondition[u[x, y] == 0, x == 0]Please visit the official Wolfram Language Reference for more details.