Provably non-stiff implementation of weak coupling conditions for hyperbolic problems

Abstract In the context of coupling hyperbolic problems, maximum stable time step an explicit numerical scheme may depend on design procedure. If this is case, procedure sensitive to changes in model parameters independent Courant–Friedrichs–Levy condition. This sensitivity can cause artificial stiffness that degrades performance a scheme. To overcome problem, we present systematic and general for weakly imposing conditions via penalty terms provably non-stiff manner. The be used construct both energy conservative dissipative couplings, user given control over amount dissipation desired. resulting formulation simple implement dual consistent. coefficients take form projection matrices based conditions. Numerical experiments demonstrate results optimal spectral radii superconvergent linear functionals.