The simulation needs to be accurate and efficient for all relevant cases:

• Steady-state or transient simulation
• Different time-stepping methods:
  • constant time steps
  • varying pre-defined time steps
  • fully automatic time-stepping procedure using predictor-corrector or aggressive target-based schemes
• Different approaches for free surface calculations:
  • moving meshes
  • linearized relationship for the saturation vs. relative conductivity curve with residual water depth
  • fully unsaturated modeling
• Parameter estimation tool on base of PEST (by J. Doherty)
• Efficient control of the simulation process with customizable real-time diagrams for all important model results

Solvers

• Newton and Picard iteration techniques for nonlinear problems
• Fast iterative and direct solvers like PCG and Restarted-OR-THOMIN with powerful preconditioners
• Alternatively algebraic multigrid solver (SAMG by K. Stueben)