TRACE User Guide  TRACE Version 9.7.5
Release Notes

New features and major changes compared to the previous version are listed below.

TRACE 9.7

  • CMake
    • Breaking Changes
      • Renamed COMPILER_OPTIMIZATION to EXTENDED_COMPILER_OPTIMIZATION
      • Removed GLOBAL_OPTIMIZATION option, use CODE_OPTIMIZATION and EXTENDED_COMPILER_OPTIMIZATION instead.
    • Optimization
      • Forward the architecture flag from the Trace cmake build system to the spliss waf build script.
    • Compatability
      • Added full support for the OneAPI Intel C/C++ compiler
      • Added warning when CPATH contains VTK include directories whenever this could cause build issues.
      • Added new CMake options to toggle features that depend on parallel HDF5:
        • ENABLE_STATISTICS_HDF5_OUTPUT
        • ENABLE_PROBE_METADATA_STORAGE
    • New Defaults
      • USE_OLD_COMM = OFF -> Use "new" communication by default.
  • Unstructured
    • Fix bug in linearTRACE. One related to the differentiation of the flux Jacobian with respect to geometry (missing recomputation of gradients) causing considerable differences between HB and linearTRACE flutter simulations in some cases and the other related to the differentiation with respect to pressure and density where changes in the temperature gradient has been not taken into account so far.
    • Make Spliss matrix fill loop for unstructured blocks actually run in parallel.
    • Fix bug in unstructured solver for thermally perfect and real gas models. The fallback to 1st order discretization in cases where the 2nd order reconstruction results in an unphysical state always produced a SERIOUS error.
  • Boundary Conditions
    • Remove deprecated ChgPanelAttribute option IMAG_FREQUENCY_SHIFT_3D_NRBC use ANGULAR_FREQUENCY_IMAG_SHIFT instead
    • Extend boundary condition controller. New available evaluation variables are: Temperature, Mach, all Velocity angles
    • New 1D non-reflecting inlet boundary conditions based on mass flow and temperature (see MASS_FLOW_INFLOW_GLOBAL_VALUES)
    • Farfield boundary conditions now work for rotating domains in combination with non-zero flow angles.
    • Not meaningful combination of BCWallViscousIsothermal and WallFunctions is now prevented for non-adiabatic walls and will now throw a SERIOUS error. Old configurations containing this combination can be updated via GMC 9.6 by resetting the wall function properties of every non-adiabatic wall in the list of the PRE-widget.
  • Turbulence modelling
    • The impact of roughness can be assessed in TRACE by prescribing the equivalent roughness ks for the surface of a "panel group". On the modeling side of view, increasing ks will decrease omega of the dissipation turbulence model equation respectively the dimensionless parameter S_R at the wall. The behavior "how this decrease will take place" defines the type of roughness in the transition rough region. See: SetSRksplus
  • Transition modelling
    • Introduce new Gamma-ReTheta-based MSC transition model (see Transition model IDs).
    • Fix false negative tripwire model sanity check in case of large number of cpus.
  • Python support
    • Allow setting of the flow direction vector. Add y and z velocities to the available output quantities.
    • No longer require runtime dependencies to build pytrace.
    • Additionally include pytrace wheel next to binary distribution.
    • Add type annotation to POST class member functions (aka POST tasks).
    • Pytrace Spliss interface also provides access to the matrix colors.
    • Fixed bug with indexing when accessing solution fields in pyposttasks).
  • FSDM (Flow Simulator Data Manager) Interface
    • Implementation of an FSDM Interface for TRACE
    • Currently supported: exchange of flow field data (from blocks and panels) and surface quantities (e.g. heat flux)
  • Initialization
    • Solver parameters MULTIMODE_LEADING_EDGE, MULTIMODE_TRAILING_EDGE, MULTIMODE_J_MIN, MULTIMODE_J_MAX, MULTIMODE_L_MIN, MULTIMODE_L_MAX can be now only configured via control file commands
    • CT body force term metadata is now only read from CGNS if build option CT_BODYFORCE_TERM is active
  • DG
    • Flow gradients are now computed directly from primitive variables using BR1/2 scheme
      • The old behavior, i.e. computing and lifting gradients from conservative variables and transforming them to primitives afterwards, can be reestablished by using the CMake option DG_GRADIENTS_SOURCE="conservative".
  • Film cooling model
    • Add slot cooling type for platform or trailing edge cooling
  • Solid Integrals and Convergence Criteria
    • The quantities heat flux and temperature have been added as integral values on solid panel groups and can be used as convergence criteria.
  • Online analysis
    • Statistics
      • Add parallel HDF5 input/output for statistics (see ComputeStatistics)
        • Automatically chosen when the desired statistics output file name has the extension 'h5'
        • A standard CGNS file will be written when a file extension of 'cgns' has been chosen.
        • Both possible extensions are searched for during restarts. This enables the output of a CGNS file for the last restart, while otherwise only HDF5 files were stored.
      • Add phase-locked averages for 3D statistics (see ActivatePhaseAverages)
      • Allow output of intermittency factor gamma also for U-RANS simulations.
      • Remove sub-option --restart, which was marked as deprecated in 9.6. Now an existing CGNS or HDF5 file is automatically used for restart.
    • DoProbe
      • Enable storing and reading of 1D probe meta data. The information is stored within a HDF5 file (md_probes.h5) and can significantly speed up the initialization process for large numbers of probe points.
      • A range of additional variables can be probed (cylindrical velocity/vorticity components, velocity angles, stagnation pressure/temperature, eddy viscosity ratio).
      • Avoid a SERIOUS message if the user forgot to define desired probing variables. Instead, primitive variables and primitive gradients are written.
    • ActivateCatalyst
      • Variables of all active transport models are now available in volume entities in Catalyst co-processing by default.
      • Eddy viscosity can be ordered using --additionalVariables option.
      • A SERIOUS message was added, if the defined catalyst script is not available. This avoids expensive simulations without requested catalyst output.
  • Benchmark Mode
  • Real Gas
    • Generalize use of realgas fluid properties using REFPROP
    • Fix multi-threading race condition during filling unstructured matrix for real gas (and TPG)
  • Thermally Perfect Gas
    • Polynomial evaluations for calculation of thermodynamic properties are based on non-dimensionalised coefficients and temperature.
    • Moving meshes are now supported in combination with the thermally perfect gas model for URANS (without phase-lag) and HB.
    • Molecular weight is used as a non-dimensional variable.
    • Enhanced stability and accuracy of the Unsteady2DFrequencyDomain boundary condition formulation for RANS and URANS time domain simulation.
    • New ChgPanelAttribute command (see FORCE_INLET_INITIALIZATION_NONIDEAL_GAS) to force the initialization of the first inner cells. This can enhance stability during startup on panels with boundary conditions that differ significantly from the initial fields.
  • Linear solver
    • Implement performance improvements of the Spliss-TRACE interface.
    • Modified structured matrix fill loop for Spliss to a more cache efficient version.
    • GMRES, preconditioned by SSOR or ILU(0) can be chosen as a linear solver for the implicit system of equations via control file command SetSolver.
    • The HB solver control file command setNumberOfSolverSweeps has been deprecated. Please use ImplicitSolverSweeps instead.
  • Harmonic Balance
    • Additional linear solvers from Spliss (SSOR, ILU0, restarted SSOR/SGS/ILU0-predonditioned GMRES) available for pseudotime stepping
    • Fully coupled LHS available for pseudo-time stepping (coupling between harmonics)
    • Lanczos filter as implemented in versions <= 9.1 is available again (behavior in versions 9.2 to 9.6 is default).
  • Adjoint solver
    • Improved correctness tests of the adjoint status by including codipacks tagging tape.
    • Building the adjoint solver now requires CodiPack >= 2.2
    • Improved the RPM method to stabilize adjoint computations
    • Minimum required Eigen3 version is now 3.3.9
    • increased maximum number of simultaneous functional evaluation to 32
  • Output control
    • New control file command SetAeroelasticityOutputInterleave for setting an output interval for aeroelasticity analysis files independent of the panel (0D) output interval.
  • Unsteady Solver
    • Add option EulerBackwardTpBlending to dynamically blend first and second order time accuracy for transport equations in the Euler Backward second order scheme.
    • Add GMC switch for option EulerBackwardTpBlending in equation settings: "Blended time-integration in transport equations" and make option switchable on block group level via control file.
    • 3D field of blending factors can be written out via WriteEulerTpBlendingFactor. It is an exponential average over the last full period written to the TRACE.cgns snapshot.
    • Avoid a SERIOUS message if the CGNS file is configured with dynamic solver blending and the user defines a constant solver blending via control file (SetRiemannSolverBlendingConstant). Since settings from the control file should always win, an error at this point is not desired anymore.
      • This implementation yielded a bug which was originally fixed in 9.8.0. A backport was done to version 9.7.4.
  • Machine Learning Framework
    • Added infrastructure for data-driven modelling using Bayesian inference.
    • Supported methods include classical field inversion (FIML), direct Fieldinversion and (CFD driven) Gene Expression Programming.
    • See user-guide section Machine Learning framework for further details.
  • Scale Resolving Simulations
    • Enable processing of Reynolds stresses specified in cylindrical coordinates as input to the synthetic turbulence generator
  • Embedded LES
    • Implement RANS to LES and LES to RANS interfaces between block groups coupled via mixing planes
    • The implementation is limited to FV LES
  • Zonal Interface
    • The zonal interface has been rewritten from scratch.
    • The new zonal interface is used by default for the HB solver. The time-domain solver default will be switched in a later version.
    • New/legacy zonal interfaces can be selected at compile time (ZONAL_DEFAULT_ALGORITHM) or via control file commands (forceNewZonal/forceLegacyZonal).
    • The new HB zonal interface can couple arbitrary frequencies with an improved performance and also supports the simulation of clocking effects.
    • The zonal-mixed interface offers better mass conservation and enhanced robustness.
  • Initialization
    • Flow fields in rotating configurations can now be initialized with absolute flow velocities.
  • linearTRACE
    • Fix flux computation for distorted cells.
  • Debugging
    • New command "WriteCellFailedSolutions" writes out a 3D integer field with information on how many times the update of physical cell values failed in the FV solver.

TRACE 9.6

  • Online analysis
    • ComputeStatistics
      • Former sub-option "averages" is now the only supported behaviour, the actual moment computation is handled by POST
      • New sub-options "reynoldsAverage" and "favreAverage" to control the averaging type
      • Remove sub-option --restart. Now an existing CGNS file is automatically used for restart.
    • ActivateCatalyst
      • Add a sub-option --outputInterval forcing TRACE to only call Catalyst API with an interval (use with care)
      • By default only primitive variables and wall shear stress are passed to Catalyst. Additional quantities are available via --additionalVariables.
      • Catalyst datasets now contain metadata on frame of reference and gas properties.
      • Add TRACE specific ParaView filters (see Co-processing with ParaView Catalyst) allowing to convert data from relative to absolute frame and duplicate periodic.
  • Harmonic balance
    • SSG/LRR- \(\omega\) and Younis' heat flux model are now available in HB
    • Solver generalized for thermally perfect gas
    • Pseudo-time movies to analyze convergence/robustness issues
    • Robustness enhancements in implicit solver through optional update modes
    • Unsteady turbulence modelling available for test cases with farfield boundaries
  • Solver control
    • Remove deprecated control file command StopRobustParm. Use StartRobustParm instead.
    • Combination of implicit solver sweeps > 1 and explicit time integration is now prohibited and a meaningful error message is dumped.
  • Turbulence modeling
    • Detached Eddy Simulation
      • Compute sub-grid length scale and DES blending factor also in the 1st ghost cell.
      • Fix bug in the computation of \(\Delta_{\text{SLS}}\) for IDDES simulations. The geometry-based length scales needs to be used at respective locations. Further explanations can be found in Comment on IDDES computations.
      • Fix bug when ordering hybrid RANS/LES quantities in ComputeStatistics. Dynamic solver blending is only accumulated, when SetRiemannSolverBlendingDES is used or defined in cgns file.
    • Combination of URANS and dynamic solver blending is now prohibited and a meaningful error message is dumped.
    • Incomplete set of turbulence inflow variables will now lead to a SERIOUS instead of falling back to default turbulence intensity and length scale.
  • Transition modelling
  • Unstructured
    • Fixes and enhancements to enable AE analysis with harmonic balance for viscous flow
      • Fix computation of gradients of harmonics in harmonic balance simulation at 1-1 block connectivities
      • Enhance accuracy of metric computation for moving meshes at 1-1 block connectivities
      • Add computation of cell gradients via the least squares fully augmented approach for harmonic balance simulations
      • Add computation of higher harmonics of transport variables
  • Boundary conditions
    • Unsteady2DFrequencyDomain boundary conditions can now be used for steady simulations in combination with thermally perfect gas
    • Riemann boundary conditions now set local state by default. To activate controller for mean condition (e.g. bandwise flux averages) use '-SET_RIEMANN_BD_VALUES_TO_MEET_MEAN_CONDITION', see SET_RIEMANN_BD_VALUES_TO_MEET_MEAN_CONDITION. With this command one can switch back to the default behaviour for versions \(\le\) 9.5.
  • Solver
    • Spliss is now the default solver for the sparse linear system arising from the implicit pseudo-time discretization.
    • It re-produces the behavior of the legacy solver in SSOR mode.
    • As long as both solvers exist, users can switch to the legacy solver using the control file command "UseLegacyLinearSolver"
  • General
    • Legacy Makefile based build system was removed
    • CMake based build system introduced in 9.5 is now the default build system
  • Discontinuous Galerkin Method
    • Enable wall functions for DG and add Reichardt's law-of-the-wall to the available functions. The probing location of the flow is fixed at the bottom of the second element from the wall.
    • Add a physics-based shock indicator function (dilatation sensor multiplied with a Ducros switch).
    • Enable user-defined fine-tuning of shock indicator function.
    • Move the shock detection down in the deck to use the gradients of the current time step.
    • Add a source-term for AVDR correction (also for FV).
  • Testing
    • Add originalReferenceRevision tag to TestCase class allowing pavayo.py to compare current to original references.

TRACE 9.5

  • Online analysis
    • DoProbe
      • Provide cell volumes and polynomial order (DG-only) for each defined probe position
      • Throw error in case of duplicate variable specification instead of producing duplicate output
      • Provide transport variables of utilized turbulence model
    • ComputeStatistics
      • Add "TurbulentDistance" to statistics output file
      • Add sub-option –hrlQuantities to obtain averaged shielding and blending function
      • Add sub-option –gamma to obtain averaged intermittency factor gamma for transitional DES simulations
    • ActivateCatalyst
      • Increase minimum version of Catalyst library to 5.8 (tested to work also with 5.10)
      • Physical time information is now passed to Catalyst dataset
      • Add support for mixed steady/unsteady configurations
      • Improved allinputsgridwriter.py
      • Add native VTK Lagrange elements activatable via '–nativeHighOrder'
    • ComputeVolumeIntegral
      • Add required variables to compute the enstrophy for the FV scheme
  • Low Mach Preconditioning
    • Implement Low Mach preconditioning for unsteady computations (see StartPrecond)
    • Implement blended viscosity for the Roe solver in unsteady low Mach preconditioned computations
  • Turbulence modeling
    • Detached Eddy Simulation
      • DES is now available in combination with \(\gamma\)-model to treat transitional flows
      • Bug fix treatment of Spalart's shielding function \(f_d\). This value was only computed correctly for vorticity-based approaches and is now computed for vorticity- and grid-based approaches.
    • Curvature correction for HellstenEARSM is no longer a separate model (previously 'HellstenEARSMcc') and can only be activated by sub-option –EARSMcurvatureCorrection/-EARSMcc
    • Enable the computation of transitional DES simulations (see Run transitional DES simulations).
    • Synthetic turbulence generator
  • Transition modeling
    • Add high eddy viscosity modification for Gamma-ReTheta transition model (see Transition model sub-options)
    • Possibility to prescribe reference band position (X and R coordinate) for QuasiUnsteadyWakeModel in the cgns
    • Change control of Tu background factor for MultiMode + QuasiUnsteadyWakeModel at interfaces. Control file command is now: 'SetBackgroundTuFactor4Interface'
    • Change behaviour of Tu background factor settings for MultiMode + QuasiUnsteadyWakeModel at entry. Default value is 0.5, if no control file command is applied in order to select certain value.
  • General
    • Add a performance index to the residual and/or screen output in order to judge the computational efficiency of a setup (see Performance Index (PID), control file command in General Solver Control).
    • Add control file command 'SetAccuracyOrder' to overwrite the accuracy order for the block groups specified in the CGNS.
    • Add CGNS backup functionality in case of '–deactivateMergeCGMS/-dmc' command line option
    • Adaptive frequency search for APFT on point probes, Fourier CGNS output and panel integral output
    • Automatic improvement of APFT matrix
    • Add possibility to write CGNS movie file with an index stride
    • Performance improvement and reduce memory usage
    • Support of fast math operations, used in RELEASE builds by default
    • Add a CMake build system to the trace_suite
    • Bug fix in Tecfile reader where TRACE would crash if a DATASETAUXDATA attribute was an empty string
  • Discontinuous Galerkin Method
    • DGSEM with LGL nodes is now the default method for the DG solver. To disable DGSEM, use control file command 'disableDGSEM'. Other setups can be still activated via the old control file syntax.
    • Enable Synthetic turbulence generator to be used with 2D distribution of inflow values and close to solid walls
    • Fix scaling of NodeBased CFL number. New convective CFL number is increased by a factor of two compared to previous releases and the viscous CFL number is increased by a factor of four to account for the correct reference space.
    • The viscous CFL number is now printed per default, if Navier-Stokes equations have been activated
    • Fix a bug in the farfield boundary condition for DG
    • Add hybrid blending weights from DG shock capturing to catalyst output
  • Discretization
    • Fix IRK for mixed steady/unsteady setups
    • Add specializations and improve SIMD vectorization of ideal gas fluxes for FV DES and LES setups to improve performance, please compile as RELEASE build with an appropriate ARCH and look for and report "Missing specialization in" warning for performance-critical setups
  • Python API
    • Allow setting outlet pressure in case of radial equilibrium setting

TRACE 9.4

  • Documentation
    • Variables read and written by TRACE/PREP/POST are now documented under Variable Names for I/O
    • Literature cited in the user guide is now stored within this project under trace/DOC/src/literature.bib
  • Solver control (General Solver Control)
    • Added command MTUSettings, setting predefined values that are used by the MTU on a standard basis.
  • Online analysis
    • Probes
      • For FV simulations, probed values are now interpolated to probe location with second order accuracy using least squares gradients
      • For DG simulations, probes values are now interpolated onto the nearest reference coordinates to the probe location determined by a newton method
      • Interpolation settings can be controlled via ProbeInterpolationSettings
      • Output format of can be switched to HDF5 via ProbeOutputFormat control file command
    • Co-processing (see ActivateCatalyst, Co-processing with ParaView Catalyst)
      • Provide panel group data
      • Provide one VTK data set per block group or panel group
      • Control which block groups or panel groups are provided
      • Store velocity as a vector in the VTK data
      • The visualization order for DG, i.e. interpolation of the solution onto a finer sampled grid, can be arbitrarily chosen (see Co-processing with ParaView Catalyst)
      • This version has been tested with Catalyst 5.8.0
  • Turbulence modeling
  • Transition modeling (new or changed Transition model sub-options)
  • Low Mach preconditioning
    • Implement Low Mach Preconditioning for thermally perfect gas. The usage is the same as for ideal gas (see StartPrecond).
  • Film cooling model
    • Improved source term distribution
    • Improved accuracy of the ASST turbulence model for use with the film cooling model
  • Harmonic balance
    • Added prototype for support of Reynolds stress models
  • Solver
    • Added a testing version of the SPLISS-Bindings as a compile time option to solve the linear system of equations in nonlinear and HB mode. Recompile with SPLISS=yes to use.
    • Added an optional CorrectorCommunication to enhance convergence rate when using the Predictor-Corrector method in nonlinear solver mode.
    • Added an ImplicitSystemRelaxationFactor that allows to significantly enhance the stability of the nonlinear and HB solver modes.
    • Added command TolerateNoSolutionUpdate for unsteady time domain simulations, allows solution update failure in all sub-iteration.
    • Added a global run time limit (Command line options), after which TRACE will be terminated and a wall-clock time depending CGNS output (controllable via CGNS node 'IntervaWallClockTime').
  • Aeroelasticity
    • Coupled (time domain) aeroelasticity simulations with the modal FSI module are now possible without prior (PREP) 3D mesh deformation calculations. In this case the finite volume mesh is updated during the coupled simulation. This allows to use a large number of structural DOFs / eigenmodes while maintaining a good efficiency.
    • Enabled mesh deformation across multiple block groups
    • Enabled mesh deformation across zonal mixed interfaces with deformation of solid wall part
  • Discontinuous Galerkin scheme
    • Prototype of zonal interface for DG is available allowing for a conservative and order-preserving non-matching interface definition
    • Added a new solution type for DG containing all polynomial coefficients in one cgns solution, which results in a massive speed-up of the 3D CGNS read and write operations
  • Thermally Perfect Gases with Variable Compositions
    • Riemann Boundary Conditions enabled for boundary values as radial distributions
    • Fixed derived variables on 2D outputs
    • POST processing with GTA enabled for 2D outputs and 0D/1D outputs (via "readInterfaceFiles" task)
    • Minor bug fixes (multiple data sets in POST, computation of total quantities, ... )
  • Unstructured
    • Ghost cells between blocks connected via their edges only can now be include in the least squares fully augmented stencil. This extends the existing cell edge connectivities feature. Except for cells which have faces both at a block connectivity and at a boundary condition panel the gradients computed via the least squares fully augmented method do no longer depended on the block splitting. The feature must be enabled via the control file command UseCellEdgeConnectivities in addition to the UseBlockEdgeConnectivities command.
    • Added the face-neighbors face-tangent augmented face gradient method to compute gradients at cell faces [64]. It is as inexpensive as the face-neighbors approach while being as stable and more accurate as the vertex averaging and least squares method. It is selected via the the option 'FaceNeighborsFT' to the control file command SetGradientSideType.
  • Distribution
    • Use make option RELEASE=yes for code compilation for productive simulations.

TRACE 9.3

  • Boundary conditions
    • 2D boundary fields (only available with Riemann boundary conditions) are duplicated circumferentially if "DATASETAUXDATA NumberOfSegments = <>" is added to the Tecplot input file. This allows non-matching boundary value fields in rotational configurations.
    • For non-adiabatic solid panels using a data file as input, support is added for files with CoordinateX and CoordinateR as coordinates (see Distribution for solid panels).
    • Synthetic turbulence according to Shur et al. [54] is available for the Riemann boundary conditions and is controlled by these commands.
  • Online analysis
    • Probes (DoProbe)
      • Add probe functionality for gradients of primitive variables.
      • Add convenience control file options for probe variable selection:
        --primitives
        --primitiveGradients
      • Generalise 1D probes to allow for arbitrarily IJK-structured topologies of the input coordinate dataset. The output dataset will have the same IJK topology. Dimensions of length 1 will be removed (as in numpy.squeeze).
      • Frequency search (DoFrequencySearch) provides functionality to detect dominant frequency in online analysis probe signals via local optimization
    • Interpolate conservative variables to analysis and boundary panels (except solids) for Fourier decomposition (for consistency with 2D movie output).
    • Add CGNS interface to switch computation of derived quantities in 2D average and Fourier files such that these derived quantities are averaged. This can be controlled via GMC.
  • Turbulence and transition modeling / control
    • the behaviour of ChangeTurbulenceSettings changed (for further details see ChangeTurbulenceSettings)
      • the option --model is mandatory and leads to a reset of ALL turbulence and transition model sub-options to default values.
      • the option --transitionModelVersion <NoVersion|Menter2004|Menter2004-01|Menter2009> is optional for \(\gamma-\text{Re}_\theta\) transition model (default version is Menter2004)
      • the option --transitionOption is removed and replaced by separate switches
      • the option --solutionMethod is moved to ChangeScalarTransportAttr, whereas ILU is now default for all transport models.
    • the default set of constants and the calculation of the streamwise velocity gradient changed for \(\gamma-\text{Re}_\theta\) transition
    • update the Vortex Street Wake Model
      • add net production option
      • add hardware selection by inflow and outflow angle
    • Implement the second version of the viscous blending model. It can be switched on using ChangeTurbulenceSettings
      --ViscousBlendingLimiterVersion2
    • Add log(omega) model variant for SSG/LRR and Wilcox RSM
    • Add anisotropic SST model for use with the film cooling model
  • Unstructured
    • In addition to the already used ghost cells at 1-1 block connectivities (cells at different blocks which share a face) now cells of a neighbor block that share edges or vertices only are included as ghost cells if the neighbor block shares a faces with the local block. Currently these cells are not written to the output CGNS file.
  • Adjoint
    • Add piggy-back method which evolves the primal and adjoint simultaneously
    • Improve adjoint harmonic balance method
    • Some bugfixes, especially regarding adjoint computations for splitted boundaries
    • Fix wrong typedef in spliss AD TypeTraits causing a false positive assertion in forward AD when using row pivotization
  • Python support

TRACE 9.2

  • Online analysis/monitoring
    • ComputeStatistics
      • Store permanent snapshots of statistics files
      • Specify sampling interleave
    • Introduce coupling to Paraview Catalyst (ActivateCatalyst)
    • Define convergence criteria based on 0D analysis values.
    • Sound power is now available as an analysis criterion and computed on split panel families in parallel using NFFTs.
    • APFT analysis
      • APFT matrices are always computed in double precision
      • APFT matrices are recomputed in every time step to avoid phase shifting
    • The variables "Mach" and "ViscosityEddyRatio" can now be used in the autocorrelation analysis
  • Boundary value output
    • New command file option ChgPanelAtt -SET_ANALYSIS_TIMESTEPS to choose an interval for temporal averaging of panel family integral values which is not equal to a period
  • Turbulence modeling
  • Linear/adjoint (GMRES) solver
    • The adjoint GMRES solver has been removed
    • The linear solver no longer supports the special case of frequency 0
  • AD-based adjoint solver
    • Prototype of adjoint HB solver implemented
    • Adjoint Vector-Mode: Calculate adjoints for n different functionals in one reverse run, at a fraction of the time neede for n reverse sweeps
    • Parallel boundary conditions are now supported in adjoint mode
    • Circumferentially splitted interfaces are now supported
    • Various methods to detect and fix divergent adjoint states during reverse mode iteration implemented
  • Data set summary
  • Added film cooling model StartFilmCoolingModel
  • Boundary Conditions
    • New option to enhance robustness by merging bands in hub and casing boundary layers (MERGE_BANDS)
    • Modal gust interface fixed for cut-off acoustic modes
  • Boundary Condition Controller (Boundary Conditions Control)
    • The controller enables the adjustment of the inlet or outlet boundary condition depending on a control variable or a ratio which can be evaluated on panels in the flow field.
  • Harmonic balance
    • Improvement of accuracy and robustness in case higher harmonics are used for transport equations
    • Turbulence model auxiliary quantities (such as shear stress norm) are now based on consistent gradient computation at block boundaries.
    • Solver now always uses nonlinear routines for solid walls and leak/bleed/cooling boundary condition.
    • CPU performance enhanced by restructuring solver
    • Menter's one-equation transition model ( \(\gamma\)-model) enabled for harmonic balance
    • Transport flux correction is enabled for HB solver and is now the default (as in standard solver).
    • Impedance boundary conditions to simulate liner configurations
    • 3D acoustic gust disturbances defined by circumferential wavenumber and radial mode order
    • Fully coupled Harmonic Sets
  • Fluid-Structure Interaction

TRACE 9.1

  • Online analysis/monitoring
  • Robustness
    • Introduce a CFL penalty to automatically stabilize critical flow conditions (SetCflPenalty)
    • Automatic control of the CFL number w.r.t. monitored flow residuals (SetCflNum)
    • Support various time stepping modes for improved robustness (SetPseudoTimeSteppingMode)
  • Acceleration
    • Support multiple sweeps with intermediate communication to increase convergence rate of the implicit solver (ImplicitSolverSweeps, ImplicitSolverSweepCommunication)
    • Use high-performance libraries for equidistant and non-equidistant Fourier transforms
    • Improved strong scalability by reworked collective communication
    • Accelerated zonal interfaces
    • Use OpenMP instead of POSIX threads for faster shared-memory parallelization
  • Turbulence modeling
    • Added controlled decay modification for Menter SST model (Controlled decay)
    • Spalart-Allmaras can now be used as background model for DES
    • JH- \(\omega^h\) model implementation as in [42]
    • Added \(log(\omega)\) modification for Wilcox k-w and Menter SST (k-log(w))
  • Discretization
  • Boundary conditions
    • Boundary conditions for Riemann boundaries no longer require band structure
    • Boundary conditions for modal blade row interfaces in harmonic balance solver ("Unsteady2DFrequencyDomain")
      • are parallel (can be used with split panel families)
      • use fast Fourier transforms (FFT or NFFT)
      • are more robust
    • Unsteady modal boundary conditions "Unsteady2DFrequencyDomain"
      • have faster convergence and improved stability properties
      • are parallel (can be used with split panel families)
      • use fast Fourier transforms (FFT or NFFT)
    • Interpolation at mixing planes with non-1-1 band distributions has been improved to be second order accurate and conservative
    • Unsteady boundary conditions, Unsteady1D and Unsteady2D (Time-Domain), can now be used on radially and circumferentially split boundaries
  • Aeroelasticity
    • Coupled Fluid-Structure Interaction simulations with eigenmodes
    • Coupled Fluid-Structure Interaction simulations with CalculiX
    • Panels with bleed boundary conditions are treated like solid boundaries the AE analysis.
    • Surface displacements are now read from 2D zones by default. Usage of the old data format, which is deprecated and will be removed in the next release, can be enabled by specifying "all immediate UseTRACE90DeformationDataFormat" in the TRACE control file.
  • Linear solver
  • Thermally Perfect Gas
    • In the non-linear time domain solver, all boundary condition types are now possible for stationary calculations (zonal, bleed, etc.)
    • All settings can be made via the Gas Model Widget in GMC (GMC version >=9.1.3).
    • An internal calculation of a mixing component is carried out for gas mixtures that are assembled internally, so that there is no performance disadvantage compared to the choice of a mono component (Mixture -> constant).
    • A first prototype is available for non-constant gas mixtures. Control is also via GMC (Mixture -> variable). In this case, specify a boundary condition and an initialization for each gas to be transported. The names correspond to the gas names.
  • Output
    • Improve accuracy of the interpolation onto panels for the 2D CGNS output.
    • All panels of structured blocks are now read and written as structured 2D zones into the 2D bases in CGNS files. The order of vertices and faces written to CGNS files may differ from those written by previous versions.
  • Licenses
    • License texts for external libraries utilized to implement the trace_suite are added in the directory LICENSES.
  • adAdjoint solver
    • Reverse accumulations can now be stabilized with the Reverse Projection Method (RPM).
    • Evaluation of adjoint sensitivities with deformed meshes can be done via POSTs evaluate sensitivities task.
    • Improved performance for adjoint simulations on unstructured meshes through preaccumulation of least square gradients.