GASP: Release Notes
Current GASP Version: 5.2.0
Version 5.2.0 has a number of new features and changes that are discussed here. With each major release (ie, 5.1 to 5.2), changes to the input deck, grid, and solution files are commonly made. Therefore, users will need to convert older input decks to the current version. This is done by opening the input deck in the GUI and selecting save from the main menu. This will automatically save the input deck to the current version. Note that this will also prevent older versions of GASP from reading the updated input deck. Therefore, it is recommended that users save a copy of older case files before converting to 5.2.
New Features in v5.2.0
- The GASP database infrastructure has been completely redesigned. The result is a new layout of the XML based database file. The new version of GASP will still read the older Version 5.1 database files, but the user is encouraged to open older database files in the database GUI and select save. This will convert the older database file to the new file format. The database GUI has also changed slightly in that it is now more flexible. The user can organize the tree structure with less restrictions (eg, species, reactions, and models can be moved to any folder for user preferred organization).
- The time integration solver now supports options such as GMRES and NKS from the Portable, Extensible Toolkit for Scientific Computation (PETSc) library. The generalized minimal residual method (GMRES) is an iterative Krylov subspace method, while NKS is a Newton-Krylov-Schwarz iterative method using a matrix-free approach. The GMRES option can be used in place of the symmetric Gauss Seidel (SGS) or Jacobi methods.
- A new solver was added for computing the stress and strain inside solid materials, as well as any displacements that may occur. The solver can be used in a stand-alone fashion in which body forces are applied to create force induced stress or it can be coupled to the solid thermodynamics solver to compute thermally induced stresses.
- Mesh adaptation is now available for unstructured grids. The user may now adapt the grid for a zone or set of zones by adding cells based on specified solution parameters.
- The Einfeldt's Harten-Lax-van Leer (HLLE) Godunov-type inviscid flux solver has been added to the Navier-Stokes solver. This flux difference splitting scheme attempts to provide more grid independence than the Roe , AUSM, or Van Leer flux schemes for high-Mach number flows.
- A large eddy simulation (LES) model was added to the Navier-Stokes solver based on the BSL/LES model. This is a hybrid LES/RANS method that uses a blending function to allow for LES in the outer portion of the boundary layer and traditional RANS near the wall. The model is applicable to high-speed flows and requires a very fine grid and time-dependent simulations to run.
- Source terms to the governing equations (eg, Navier-Stokes, Solid Thermodynamics, etc) can be added by the user on a zone by zone basis. This is done by providing an ASCII file with the source values for each equation solved.
- GASP now supports global variables that are defined once for a given input deck. The variables can then be used to replace numeric values throughout the input deck.
- The file output infrastructure has been redesigned to be more memory efficient. Older versions of GASP used to collect data on zones before computing output quantities. For large zones, this could potentially cause memory issues for the GUI or root process in the solver. Output quantities are now computed on the partitions (that result from decomposition of a zone) before being collected on a zone. This is an internal change that is not reflected in the GUI, but needs to be mentioned since it improves the output performance from GASP.
Details of using GASP and what is new in v5.2.0 can be found
in the GASP Users Guide located in the install directory: