GASP Version 4 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 steady and unsteady linear Sensitivity Equations

Physical Modeling - Fluxes and Jacobians

• Roe, Modified-Roe, Van Leer and AUSM+ flux splittings
• Preconditioned-Roe (extends application to M << 1)
• Approximate Roe linearization, complete Van Leer Jacobian
• Artificial compressibility flux option for incompressible, perfect gas flows
• Higher order MUSCL reconstruction
• True high-order ENO reconstruction

Physical Modeling - Thermodynamic and Transport Properties

• 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<\li>
• Stand alone database manager
• Extended rate equation curve fits
• Complete reaction sets for existing chemistry models
• Park's two-temperature kinetic model for ionizing air
• Optional Damkohler limiting for suppressing transient instabilities

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
• Full integration with thermo-chemical database

Physical Modeling - Turbulence Models

• Baldwin-Lomax algebraic model in any two logical directions
• Supports user-input intermittency values for transition modeling
• Spalart Allmaras
• Spalart Allmaras with Detached Eddy Simulation (DES)
• K-epsilon (High Reynolds Number, Chien and Lam Bremhorst)
• Wilcox K-omega (1988 and 1998 versions) with compressibility correction.
• Mentor's SST model for K-omega
• Reynolds Stress Model (Wilcox Stress-Omega)

Physical Modeling - Solid Thermodynamics

• Material database with properties
• Variable temperature properties supported
• Solids with different materials supported

Physical Modeling - High Energy Lasers (U.S. Only)

• Output HEL specific variables
• Stable Resonator Optics Model
• COIL and HF Chemistry Models

Discretization

• Multi-block structured grid topology
• Chimera/Overset grids
  -- Built-in hole-cutting and stencil selection
  -- Robust treatment of orphans
  -- Surface projection for overlapping viscous 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
• 1^st, 2^nd, and 3^rd order time accurate option (dual-time stepping)
• Solution file can save separate solutions incrementally in time
• Time-dependent freestream conditions applied to any boundary condition
• Chimera calculations automated from one time step to the next
• Explicit Runge-Kutta option for time accurate flows

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 from one time step to the next

Time Integration

• Full 3-D solvers (Symmetric Point Gauss Seidel and Point Jacobi)
• Implicit coupling across point to point zonal boundaries
• Implicit boundary conditions
• Euler Explicit Solver
• Uncoupling of systems including turbulence and chemistry for improved computational efficiency

Parallel Computing

• Distributed memory model using MPI<\li>
• Support for most parallel computers, as well as clusters of workstations
• Integrated domain decomposition is isolated from the user<\li>
• Support for full implicit time integration in parallel
• Hole cutting and Chimera stencil searches are performed in parallel
• Support for semi-automated load balancing
• Load balancing accounts for different processor speeds
• Allows 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 XML input deck file

Portable Binary File Format

• Binary files for both solution and grid are platform independent
• Solution and grid are in separate files (including those for saved time steps)

Solution/Convergence Monitor

• Watch points
  -- Print any variable at a specified point or along a specified line each time step
  -- Integrate quantities each time step (watch skin friction, lift or drag)
• File names automatically incremented with cycle number or physical time

Miscellaneous