Providing Quality CFD
Software and Solutions
Features
Basic Features
- Solves steady and unsteady 3-D, Reynolds-Averaged,
Navier-Stokes Equations (RANS) and subsets:
-- Thin-layer Navier-Stokes (TLNS)
-- Parabolized Navier-Stokes (PNS)
-- Euler equations
-- Incompressible Navier-Stokes - Solves steady and unsteady 3-D heat equation including conjugate heat transfer
- Solves for stress and displacements due to thermal or applied loads.
Physical Modeling - Fluxes
- Roe, Modified-Roe, Van Leer, HLLE+ and AUSM+ flux splittings
- Yee low dissipation flux scheme
- Preconditioned-Roe (extends flows to low Mach numbers)
- Preconditioned Weiss-Smith flux scheme
- Artificial compressibility flux option for incompressible, perfect gas flows
- Higher order MUSCL reconstruction
- True high-order ENO reconstruction
Physical Modeling - Thermodynamics
- Equilibrium and non-equilibrium (U.S. only) thermodynamics models
- NASA GRC extended curve fit option
- Extended transport properties for air to 30,000 K
Physical Modeling - Chemistry Models
- Species and Reaction databases for thermochemical properties
- Stand alone database manager (GUI based)
- Extended rate equation curve fits
- Complete reaction sets for existing chemistry models
- Park's two-temperature kinetic model for ionizing air
Physical Modeling - Two Phase Flow
- Lagrangian formulation for particle tracking
- Support for solid and liquid particles
- Evaporation models
- Compatible with steady and time dependent simulations
- Wall rebound models
- Drag models
Physical Modeling - Turbulence Models
- Baldwin-Lomax algebraic model in any two logical directions (structured grids only)
- Spalart Allmaras one-equation model
- K-epsilon (High Reynolds Number, Chien and Lam Bremhorst)
- Wilcox K-omega (1988, 1998, and 2006 versions) with compressibility correction.
- K-length (Smith and Goldberg)
- Mentor's SST model for K-omega
- Reynolds Stress Model (Wilcox Stress-Omega)
- Detached Eddy Simulation (DES) based on Spalart Allmaras model and SST models
- Large Eddy Simulation (LES) hybrid model based on the work by Gieseking et. al.
- Supports user-input intermittency values for transition modeling
Physical Modeling - Solid Thermodynamics
- Material database with properties
- Variable temperature properties supported
- Solids with different materials supported
Physical Modeling - Mechanical Stress
- Solves for material displacements due to external forces or thermal stress
Post-Processing
- Support for PLOT3D, TECPLOT, Ensight and Fieldview
- Simplified user interface for computing integrated quantities (e.g., lift and drag)
- Support for blanking within PLOT3D type output
- English, SI, and user defined unit systems
- Automatic execution of post-processing at end of CFD run
- Access to all time levels stored in the solution files
- User defined output variables
Discretization
- Multi-block structured/unstructured grid topology
- Unstructured mesh support for tetrahdra, hexahedra, prisms, and pyramids
- Chimera/Overset grids (structured grids only)
-- Built-in hole-cutting and stencil selection
-- Robust treatment of orphans
-- Surface projection for overlapping grids
-- Dual fringe point interpolation for increased spatial accuracy
-- 3-D visualization and statistics for holes, interpolation cells, and orphans - Point-to-point and non-matching zonal boundary
interpolation
-- Automated point-to-point zonal boundary detection - Automated mesh sequencing
Temporal Accuracy
- Steady state option
- 1st, 2nd, and 3rd order time accurate option
- Implicit Dual-time-stepping and Newton sub-iterations
- Explicit Runge-Kutta option for time accurate flows
- Solution file can save separate solutions incrementally in time
- Time-dependent freestream conditions applied to any boundary condition
Motion Modeling (U.S. Only)
- Kinematics models:
-- 6 DOF models (multiple bodies with separate weights, c.g.'s and moments of intertia)
-- Constrained motion database - Chimera calculations automated between time steps
Time Integration
- Integration with Portable Extensible Toolkit for Scientific Computation (PETSc) library
- Full Implicit 3-D solvers (Symmetric Point Gauss Seidel, Point Jacobi, and GMRES)
- Implicit coupling across point to point zonal boundaries
- Implicit boundary conditions
- Uncoupling of systems including turbulence and chemistry for improved computational efficiency
- Operator splitting for chemical source terms (using DVODE)
- Euler Explicit Solver
Parallel Computing
- Distributed memory model using MPI
- Support for most parallel computers, including clusters
- Integrated domain decomposition is transparent to the user
- Support for full implicit time integration in parallel
- Parallel hole cutting and Chimera stencil searches
- Support for semi-automated load balancing
- Different domain decomposition on different grid sequences
Graphical User Interfaces
- All GUI interfaces integrated into single application (both pre- and post-processing in a single application)
- Complete integration with the 3-D viewing window
- Most features accessible from a single window
-- Extensive use of "tab sheets" and tables for organization and layout - Graphics states saved in problem file
Miscellaneous
- Binary files for both solution and grid are platform independent
- Solution and grid are in separate files (including those for saved time steps)
- Support for user-specified unit systems
Solution Visualization
- Leverages VTK open source library
- Support for most visualization primitives
-- Line or flooded contours, isosurfaces, velocity vectors streamlines using tubes, ribbons, and bubbles, cutting planes - Line plotting from within the GUI
- Creation of movies and snapshots from GUI