Solver Specifications#
This required section directs the nonlinear iteration strategy with associated parameters (e.g., Newton’s method options), matrix solution strategy and parameters, and other sundry options and toggles for the pressure stabilization approach and linear stability analysis capability. With regard to the parameters associated with matrix solution methods, it is important to understand that there are two major classes of solvers - direct and iterative solvers. Direct solvers are the most robust, but can be computationally impractical for some larger systems. Iterative solvers and associated preconditioners are the only practical options for large-scale problems (viz., very large twodimensional problems and virtually all three-dimensional problems). Choosing the solver settings for good convergence of iterative matrix solvers can be an artful task for Navier-Stokes problems and other poorly conditioned systems. It is recommended that the user consult the comprehensive report by Schunk, et al. (2002) for an overview and further usage tips.
- Strong Boundary Condition Replace Equation
- Strong Boundary Condition Penalty
- Total Number of Matrices
- Solution Algorithm
- Matrix Storage Format
- Stratimikos File
- Preconditioner
- Matrix Subdomain Solver
- Matrix Scaling
- Matrix Residual Norm Type
- Matrix Output Type
- Matrix Factorization Reuse
- Matrix Graph Fillin
- Matrix Factorization Overlap
- Matrix Overlap Type
- Matrix Auxiliary Vector
- Matrix Drop Tolerance
- Matrix Polynomial Order
- Matrix Reorder
- Matrix Factorization Save
- Matrix ILUT Fill Factor
- Matrix RILU Relax Factor
- Matrix BILU Threshold
- Matrix Relative Threshold
- Matrix Absolute Threshold
- Size of Krylov Subspace
- Orthogonalization
- Maximum Linear Solve Iterations
- Number of Newton Iterations
- Modified Newton Tolerance
- Jacobian Reform Time Stride
- Newton line search type
- Newton Correction Factor
- Normalized Residual Tolerance
- Normalized Correction Tolerance
- Residual Ratio Tolerance
- Residual Relative Tolerance
- Pressure Stabilization
- Pressure Stabilization Scaling
- Pressure Stabilization Disable Tau Sens
- Pressure Stabilization Lagged Tau
- SUPG Disable Tau Sens
- Lagged Tau
- Use AutoDiff Assembly
- Linear Stability
- Filter Concentration
- Disable Viscosity Sensitivities