ANSYS CFX Release 11.0 Technical Specifications

ANSYS Workbench Platform

• ANSYS CFX components run stand-alone or integrated into the ANSYS Workbench engineering simulation platform. Persistent settings that connect each step in the solution process allow design iterations to be generated quickly and easily compared to determine optimal designs.
• ANSYS Workbench provides unified data sharing and project file management across the range of ANSYS products.
• New at release 11.0, the parameter manager of ANSYS Workbench enables setup of a series of simulations to study the operating range of a product or to investigate and compare several alternative designs. The parameterized geometry and physics description, combined with the automatic calculation of performance metrics, allows the operating range of the product or process to be established quickly.
• Design of experiments, deterministic and robust design optimization techniques can now be applied to CFD using ANSYS DesignXplorer.

ANSYS CFX Modeling Capabilities

• Solution on any mixture of tetrahedral, hexahedral, prism and/or pyramid elements
• Incompressible/compressible — subsonic, transonic, supersonic
• High-speed numerics treatment for better shock capturing
• Steady state/transient
• Laminar/turbulent

Physics Pre-Processor

• Import of meshes from a wide variety of sources/formats
• Automatic generation of interfaces between physical domains
• Manual labeling of regions of mesh faces
• Transform and connect multiple meshes using the generalized grid interface
• Intuitive problem definition
• Application-specific wizards (Quick Set-up and TurboPre™)
• Flexible fluids editor, including common fluids library
• Expression language for general user-defined functions
  • Fluid properties
  • Equation sources 
  • Boundary condition profiles 
  • Initial conditions
• Visualization of profile and expression boundary conditions in the pre-processor 
• Executable in batch mode and provides full access to CFX Command Language CCL power syntax for advanced/custom applications and macros 
• Context-sensitive online user documentation with hyperlinks 

Boundary Conditions

• Inlet: mass flow and flow direction, velocity, static pressure and direction, total pressure and direction, total enthalpy, total temperature, static temperature, subsonic, supersonic and mixed (combined subsonic and supersonic)
• Outlet: mass flow (with pressure profile or circumferential average pressure profile), velocity, uniform static pressure, average static pressure, circumferential average static pressure, subsonic, supersonic, degassing condition, meridional pressure profile, zero gradient condition
• Opening (mixed inflow/outflow): velocity, static (in)/static (out) pressure and direction, total (in)/static(out) pressure and direction, local flow direction or entrainment
• Wall: no slip, free slip, rough, moving, adiabatic, temperature-specified, heat flux, heat transfer coefficient
• Opaque, black body, radiation intensity conditions
• Symmetry
• Thin surface walls
• 1-D or 2-D profile specifications for any quantity

Multidomain and Domain Interface Models

• Rotating fluid domains
• Porous domains
• Alternate rotation velocity advection model
• Multiple frames of reference
• Frozen rotor interface model
• Stage interface model
• Pitch change model
• Constant stationary frame pressure stage interface model
• Transient rotor/stator interface model
• Translational and rotational periodic connections
• Translational periodic connections with pressure change and mass flow rate
• Conservative algebraic fluid porous interfaces

Turbulence Models

• Algebraic (zero-equation) model
• k-ε, RNG k-ε
• Shear stress transport
• k-omega
• Reynolds stress transport model (second moment closure)
• k-omega Reynolds stress
• Detached eddy simulation (DES) turbulence model
• SST scale adaptive simulation (SAS) turbulence model
• Smagorinsky large eddy simulation model (LES)
• Scalable wall functions
• Automatic near-wall treatment including integration to the wall
• User-defined turbulent wall functions and heat transfer
• Predictive Menter-Langtry γ-θ laminar-turbulent transition model

Heat Transfer

• None, isothermal, thermal energy or total energy
• Viscous heating
• Conjugate heat transfer
• Natural convection
• Radiation
• P1 (diffuse) radiation model
• Rosseland radiation model
• Participating media and surface-to-surface discrete transfer radiation models
• Participating media and surface-to-surface Monte Carlo radiation models

Generalized Grid Interface

• Import and connect multiple meshes from independent sources
• Detailed control of non-overlap conditions
• Rasterized or direct mesh intersection algorithms

Combustion

• Single and multi-step EDM reaction modeling with:
• Chemical kinetics
• EDM maximum flame temperature model
• Ignition and extinction models
• Pre-defined reaction and materials libraries (user-modifiable)
• Coupled solution of multi-step reactions for strong convergence and robustness
• PDF-type combustion models for detailed chemistry
  • Flamelet model for diffusion flames
  • Zimont model for premixed/partially premixed combustion
• NOx models
• Magnusson soot model
• Combustion with single or multiphase flow
• Weighted reaction progress model for partially premixed combustion
• Turbulent and laminar burning velocity correlations
• Spark ignition model
• Chemistry (for example, NOx) post-processing mode

User-Defined Equations and Species Transport

• Advective/diffusive transport
• Diffusive transport
• Poission equation
• Scalar and vector algebraic additional variables

Material Properties

• Ideal gas equation of state
• NASA format temperature-dependent Cp
• Quartic polynomial temperature-dependent ideal gas Cp
• Redlich–Kwong equation of state for gases
• IAPWS IF-97 equation of state for water
• Antione equation for vapor pressure curves of pure substances
• Temperature-dependent viscosity and thermal conductivity models including Sutherlands law, modified Eucken and non-interacting sphere models
• Newtonian and non-Newtonian fluids
• User-defined thermodynamic properties through tables or CEL expressions or user Fortran
• User-defined transport, properties through tables, CEL expressions or user Fortran
• User-defined radiation and electromagnetic properties through CEL expressions or user Fortran
• Pre-supplied database of materials
• Multi-component fluids

Eulerian Multiphase Models

• Algebraic slip multiphase model
• Homogenous or fluid-dependent mass and momentum equations
• Homogenous or fluid-dependent turbulence equations
• Homogenous or fluid-dependent energy equations
• No limit on number of phases
  • Drag force models
  • Grace drag factor for bubbles
  • Schiller–Naumann drag model for particle
  • Ishii–Zuber model
  • Wen Yu model
  • General user-defined drag coefficient
• Non-drag force models
  • Dense particle effects and solids pressure forces
  • Kinetic theory for dense particle effects
  • Turbulent dispersion force
  • Lift force
  • Pressure gradient force
  • Virtual mass force
  • Wall lubrication
• Interphase heat transfer
  • Specification of interface flux heat transfer coefficient, Nusselt number, Hughmark or Ranz–Marshall correlations
  • Interphase variable transfer
  • Specification of interface flux, transfer coefficient, Sherwood number, Hughmark or Ranz–Marshall correlations
• Interphase mass transfer
  • Equilibrium phase change model
  • Thermal phase change model (evaporation, condensation, bulk boiling)
  • Non-equilibrium droplet nucleation and phase change model (evaporation, condensation)
  • Cavitation model (Rayleigh–Plesset)
  • Multiple size group (MUSIG) bubble model
  • Specification of interface flux, transfer coefficient, Sherwood number, Hughmark or Ranz–Marshall correlations

Coupled Lagrangian Particle Tracking Model

• Massless, one-way or full two-way momentum transfer
• Steady state or transient
• Moving mesh support
• Particle drag models
• Detailed control of injection locations, size distributions (6+ distribution functions), etc.
• Particle erosion models
• Wall breakup models
• Primary breakup models: BLOB, EBLOB and sheet atomization
• Spray penetration diagnostics
• Secondary breakup models: Reitz and Diwakar, TAB, ETAB, Schmehl, CAB
• Virtual mass, pressure gradient and turbulent dispersion forces
• Evaporating liquid droplets
• Oil combustion model
• Coal combustion model with proximate/ultimate hydrocarbon fuel analysis
• Local particle and vertex-averaged results
• User Fortran control of particle injection and particle models
• Fully parallelized

Free Surface Modeling

• Compressive discretization
• Homogenous or interphase transfer models
• Surface tension

Noise Modeling

• Lighthill stress output
• Export of monopole, dipole and rotating dipole sources for acoustics solvers

Source Models

• Linear and quadratic resistance models
• Permeability and loss coefficient models
• User-defined volumetric sources of mass, momentum, energy and species
• User-defined boundary sources of mass, momentum, energy and species

Moving and Deforming Mesh

• Steady state and transient analysis
• Automatic robust mesh stiffness calculation
• Steady state and transient analysis
• Mesh morphing from prescribed surface or volume movement
• Explicit volume mesh movement via user Fortran
• Support for general grid interfaces
• Solution-based mesh adaption

Fluid Structure Interaction

• One-way coupling between ANSYS and ANSYS CFX suitable for steady state analysis
• Two-way FSI capability for time transient or steady state analysis with moving/deforming geometry
• Conservative profile-preserving interpolation for fluid dynamic forces and heat flows

Numerics

• Conservative finite element based control volume method
• Implicit, pressure-based algorithm for all flow speeds, incompressible to compressible
• Advection modeling
• Upwind difference advection scheme
• 1st- and 2nd-order blend factor
• High-resolution bounded advection scheme
• Robust and accurate diffusion discretisation scheme
• Conservative 1st- and 2nd-order transient discretisation with adaptive transient time stepping

Linear Solver

• Coupled solution of mass and momentum, including multiphase flows
• Coupled solution of energy for multiphase flows
• Coupled solution of additional variables for multiphase flows
• Algebraic multigrid
• Incomplete upper/lower factorization (ILU) smoother
• Linear performance for even large numbers of nodes

Parallel Computing

• Homogenous or heterogeneous networks of UNIX and/or Windows platforms
• PVM or MPI parallel communication libraries
• Vendor specific MPI support
• MPI support on Linux for high speed interconnects (Myrinet, Infiniband, Quadrics)
• Automated domain partitioning
• Scalable execution time over a large number of processors, with efficiencies exceeding 90 percent for large problems
• Scalable memory usage

User Modeling and Solution Control

• Dynamic tracking of monitor point and boundary flow values
• Dynamic command file re-read
• Modify solver parameters and boundary condition values as solution proceeds
• Expression language for user-defined functions for fluid properties, equation sources, boundary condition profiles and initial conditions. A wide range of intrinsic functions are supported including:
  • Dynamic evaluation of boundary values and flows
  • 1-D or 3-D cloud of point data interpolation
  • User subroutine interface for fully programmable user function

ANSYS CFX Post-Processing

The ANSYS CFX post-processor provides a powerful and flexible analysis system for ANSYS CFX results. Its capabilities are summarized below.

• Automated report generation
  • Report generation (comments, figures, charts, tables)
  • Report templates can be established that include all charts, tables, figures, and then re-used for each design to allow easy comparison of design alternatives.
  • HTML report export
• General post-processing capabilities
• Simultaneous load of multiple results
• Automatic region recalculation after results reload
• Context-sensitive help
• Unlimited undo and redo
• Configurable mouse buttons
• Configurable units specification
• Configurable look and feel 
• Object picking, dragging and dynamic highlighting
• Context-sensitive right-click object control in the viewer
• Session recording and playback
• State save and restore
• Batch processing
• Fully programmable post-processing including loops, logic, subroutines (macros)
• Data import/export
  • Reads results in ANSYS CFX, CFX-4, CFX-TASCflow, ANSYS shell and 3-D elements or CGNS formats
  • Import of external data (surfaces, lines, charts)
  • Image output to postscript, jpeg, png, bmp, and ppm
  • 3-D scene output to CVF (ANSYS CFX Viewer format) and VRML
  • Embed 3-D interactive scene output and viewer in PowerPoint software via HTML
• Graphics capabilities
  • Multiple viewer windows
  • Pre-defined and user-defined views
  • Scene clipping
  • Points and point clouds (object sampling)
  • Slice planes (unbounded and bounded)
  • Circular and rectangular sample planes 
  • Isosurfaces 
  • Surfaces or revolution
  • Volumes from iso-values, sphere, surface intersection
  • Lines and polylines (2-point, external data or region/slice intersection)
  • Surface groups 
  • Offset surfaces
  • Coloring any surface, line or point by variables 
  • Contours/fringes
  • Streamlines and surface streamlines 
  • Vectors
  • XY charts (variable on a line, time chart or from file)
  • Rendering control of faces, lines, lighting, transparency and texture mapping
  • 2-D and 3-D text labels and annotations
• Animation creation
  • Quick animation (planes, isosurfaces, mesh displacement, timesteps)
  • Detailed key-frame animation
  • MPEG output
• Quantitative post-processing
  • Interactive data probe
  • Node count, mass flow, length, area and volume evaluation
  • Length, area, volume and mass flow-based averaging and integration
  • Force and torque calculation
  • Support of all above functions in expressions 
  • User defined variables
  • Mesh quality analysis 
  • Quantitative tables in a spreadsheet-like environment
• Turbomachinery post-processing
  • Turbo slices (m', theta, span)
  • 3-D or turbo views (b2b, meridional) 
  • Circumferential averaging 
  • Cylindrical vectors 
  • Turbo-specific plots, performance macros and reports

Beta Features

ANSYS CFX release 11.0 includes a number of released (visible) and unreleased (hidden) “beta” features that demonstrate capabilities currently in development within ANSYS CFX. These capabilities are largely untested, unsupported, and subject to change in future releases.            

Released beta features are visible in CFX-Pre if you select to activate beta features. Unreleased beta features are not generally visible within the product and usually entail usage of custom CFX Command Language, user Fortran or activation of CFX solver expert parameters.  Hidden beta features may be made available to selected users who have demonstrated a need and understanding of the nature of these features.            

Some of the beta features available within ANSYS CFX release 11.0 include:

Released (Visible) Beta Features

• Non-reflective acoustic boundary conditions (inlet, outlet and opening conditions supported)
• Independent physics modeling between disconnected domains
• Additional turbulence models including Spalart–Allmaras, and explicit algebraic Reynolds stress model, dynamic and WALE large eddy simulation
• Re-attaching and swirling flow corrections for two-equation RANS models
• Roughness modification for the transition model
• Fluid–solid interfaces with pitch and shape change
• Conjugate additional variables and additional variables in solid domains
• Rotating CHT solid domains
• Rotating advection term for rotating solid domains (allowed in energy and transported additional variable equations)
• Zero gradient boundary conditions for volume fractions allows automatic height calculation for subcritical free surface flows
• MHD support including:
  • Potential equations for both electric and magnetic fields in connected fluid and solid domains with conjugate coupling
  • Lorentz force in momentum equation
  • Joule heating term in energy equation
  • Electromagnetic force effects on particles

Unreleased (Hidden) Beta Features

• An inhomogenous MUSIG Eulerian multiphase model
• Custom drift mass flows for ASM
  
• Stiff chemistry solver
  
• Rough wall treatment for k-omega-based turbulence models
  
• Additional variable transport in solid domains and through solid–fluid interfaces
  
• Improved Eulerian multiphase transient schemes
  
• Peng–Robinson equation of state for gases and subcooled liquids
  
• Real liquid property support with saturation clipping
  
• Non-Newtonian dynamic viscosity models
  
• Orthotropic thermal conductivity and diffusivity for additional variables

Platform Support

UNIX Workstations

• Hewlett-Packard PA-RISC or IA-64 Itanium® running HP-UX 11i
• SUN UltraSPARC running Solaris 9 or 10
• SGI running IRIX  6.5.19
• IBM Power  running AIX 5.3
• Batch solver support on HP-Compaq running TruUnix 5.1

32- or 64-Bit Windows and Linux

• 32- bit Windows 2000 or  XP, Windows XP64
  
• RedHat Enterprise Linux 3 or 4
  
• SuSE Professional Linux 9 or 10
  
• SLES 9

Double precision and 64-bit memory addressing available on all platforms.