- •Why CFD is Important for Modeling
- •How the CFD Module Helps Improve Your Modeling
- •Model Builder Options for Physics Feature Node Settings Windows
- •Where Do I Access the Documentation and Model Library?
- •Typographical Conventions
- •Quick Start Guide
- •Modeling Strategy
- •Geometrical Complexities
- •Material Properties
- •Defining the Physics
- •Meshing
- •The Choice of Solver and Solver Settings
- •Coupling to Other Physics Interfaces
- •Adding a Chemical Species Transport Interface
- •Equation
- •Discretization
- •Transport Feature
- •Migration in Electric Field
- •Reactions
- •Reactions
- •Initial Values
- •Initial Values
- •Boundary Conditions for the Transport of Concentrated Species Interface
- •Mass Fraction
- •Mass Fraction
- •Flux
- •Inflow
- •Inflow
- •No Flux
- •Outflow
- •Flux Discontinuity
- •Flux Discontinuity
- •Symmetry
- •Open Boundary
- •Physical Model
- •Transport Properties
- •Model Inputs
- •Fluid Properties
- •Diffusion
- •Migration in Electric Field
- •Diffusion
- •Model Inputs
- •Density
- •Diffusion
- •Porous Matrix Properties
- •Porous Matrix Properties
- •Initial Values
- •Initial Values
- •Domain Features for the Reacting Flow, Concentrated Species Interface
- •Boundary Conditions for the Reacting Flow, Concentrated Species Interface
- •Reacting Boundary
- •Inward Flux
- •Physical Model
- •Transport Properties
- •Fluid Properties
- •Migration in Electric Field
- •Porous Matrix Properties
- •Initial Values
- •Domain Features for the Reacting Flow, Diluted Species Interface
- •Boundary Conditions for the Reacting Flow, Diluted Species Interface
- •Pair and Point Conditions for the Reacting Flow, Diluted Species Interface
- •Multicomponent Mass Transport
- •Multicomponent Diffusion: Mixture-Average Approximation
- •Multispecies Diffusion: Fick’s Law Approximation
- •Multicomponent Thermal Diffusion
- •References for the Transport of Concentrated Species Interface
- •Domain Equations
- •Combined Boundary Conditions
- •Effective Mass Transport Parameters in Porous Media
- •Selecting the Right Interface
- •The Single-Phase Flow Interface Options
- •Laminar Flow
- •Coupling to Other Physics Interfaces
- •The Laminar Flow Interface
- •Discretization
- •The Creeping Flow Interface
- •Discretization
- •Fluid Properties
- •Fluid Properties
- •Mixing Length Limit
- •Volume Force
- •Volume Force
- •Initial Values
- •Initial Values
- •The Turbulent Flow, Spalart-Allmaras Interface
- •The Rotating Machinery, Laminar Flow Interface
- •Rotating Domain
- •Rotating Domain
- •Initial Values
- •Initial Values
- •Rotating Wall
- •Wall
- •Boundary Condition
- •Interior Wall
- •Boundary Condition
- •Inlet
- •Boundary Condition
- •Velocity
- •Pressure, No Viscous Stress
- •Normal Stress
- •Outlet
- •Boundary Condition
- •Pressure
- •Laminar Outflow
- •No Viscous Stress
- •Vacuum Pump
- •Symmetry
- •Open Boundary
- •Boundary Stress
- •Boundary Condition
- •Periodic Flow Condition
- •Flow Continuity
- •Pressure Point Constraint
- •Non-Newtonian Flow—The Power Law and the Carreau Model
- •Theory for the Pressure, No Viscous Stress Boundary Condition
- •Theory for the Laminar Inflow Condition
- •Theory for the Laminar Outflow Condition
- •Theory for the Slip Velocity Wall Boundary Condition
- •Theory for the Vacuum Pump Outlet Condition
- •Theory for the No Viscous Stress Condition
- •Theory for the Mass Flow Inlet Condition
- •Turbulence Modeling
- •Eddy Viscosity
- •Wall Functions
- •Initial Values
- •Wall Distance
- •Inlet Values for the Turbulence Length Scale and Intensity
- •Initial Values
- •The Spalart-Allmaras Turbulence Model
- •Inlet Values for the Turbulence Length Scale and Intensity
- •Pseudo Time Stepping for Turbulent Flow Models
- •References for the Single-Phase Flow, Turbulent Flow Interfaces
- •Selecting the Right Interface
- •Coupling to Other Physics Interfaces
- •Discretization
- •Fluid-Film Properties
- •Initial Values
- •Initial Values
- •Inlet
- •Outlet
- •Wall
- •Symmetry
- •Discretization
- •Initial Values
- •Initial Values
- •Fluid-Film Properties
- •Border
- •Inlet
- •Outlet
- •Conditions for Film Damping
- •The Reynolds Equation
- •Structural Loads
- •Gas Outflow Conditions
- •Rarefaction and Slip Effects
- •Geometry Orientations
- •References for the Thin-Film Flow Interfaces
- •Selecting the Right Interface
- •The Multiphase Flow Interface Options
- •The Relationship Between the Interfaces
- •Bubbly Flow
- •Coupling to Other Physics Interfaces
- •The Laminar Two-Phase Flow, Level Set Interface
- •Discretization
- •The Laminar Two-Phase Flow, Phase Field Interface
- •Domain Level Settings for the Level Set and Phase Field Interfaces
- •Fluid Properties
- •Mixing Length Limit
- •Initial Values
- •Initial Values
- •Volume Force
- •Volume Force
- •Gravity
- •Boundary Conditions for the Level Set and Phase Field Interfaces
- •Wall
- •Boundary Condition
- •Initial Interface
- •The Turbulent Flow, Two-Phase Flow, Level Set Interface
- •The Turbulent Two-Phase Flow, Phase Field Interface
- •Wall Distance Interface and the Distance Equation
- •Level Set and Phase Field Equations
- •Conservative and Non-Conservative Formulations
- •Phase Initialization
- •Numerical Stabilization
- •References for the Level Set and Phase Field Interfaces
- •Stabilization
- •Discretization
- •Level Set Model
- •Initial Values
- •Initial Values
- •Boundary Conditions for the Level Set Function
- •Inlet
- •Initial Interface
- •No Flow
- •Outlet
- •Symmetry
- •Discretization
- •Initial Values
- •Initial Values
- •Phase Field Model
- •Boundary Conditions for the Phase Field Function
- •Initial Interface
- •Inlet
- •Wetted Wall
- •Wetted Wall
- •Outlet
- •The Level Set Method
- •Conservative and Non-Conservative Form
- •Initializing the Level Set Function
- •Variables For Geometric Properties of the Interface
- •Reference for the Level Set Interface
- •About the Phase Field Method
- •The Equations for the Phase Field Method
- •Conservative and Non-Conservative Forms
- •Additional Sources of Free Energy
- •Variables and Expressions
- •Reference For the Phase Field Interface
- •The Laminar Bubbly Flow Interface
- •Reference Pressure
- •Discretization
- •The Turbulent Bubbly Flow Interface
- •Reference Pressure
- •Discretization
- •Fluid Properties
- •Slip Model
- •Initial Values
- •Initial Values
- •Volume Force
- •Volume Force
- •Gravity
- •Gravity
- •Mass Transfer
- •Mass Transfer
- •Boundary Conditions for the Bubbly Flow Interfaces
- •Wall
- •Liquid Boundary Condition
- •Gas Boundary Condition
- •Inlet
- •Liquid Boundary Condition
- •Gas Boundary Condition
- •Outlet
- •Liquid Boundary Condition
- •Gas Boundary Condition
- •Symmetry
- •Gas Boundary Conditions Equations
- •The Mixture Model, Laminar Flow Interface
- •Stabilization
- •Discretization
- •The Mixture Model, Turbulent Flow Interface
- •Stabilization
- •Mixture Properties
- •Mass Transfer
- •Mass Transfer
- •Initial Values
- •Initial Values
- •Volume Force
- •Volume Force
- •Gravity
- •Gravity
- •Boundary Conditions for the Mixture Model Interfaces
- •Wall
- •Mixture Boundary Condition
- •Dispersed Phase Boundary Condition
- •Inlet
- •Mixture Boundary Condition
- •Dispersed Phase Boundary Condition
- •Outlet
- •Mixture Boundary Condition
- •Symmetry
- •The Bubbly Flow Equations
- •Turbulence Modeling in Bubbly Flow Applications
- •References for the Bubbly Flow Interfaces
- •The Mixture Model Equations
- •Dispersed Phase Boundary Conditions Equations
- •Turbulence Modeling in Mixture Models
- •Slip Velocity Models
- •References for the Mixture Model Interfaces
- •Dispersed Phase
- •Discretization
- •Domain Conditions for the Euler-Euler Model, Laminar Flow Interface
- •Phase Properties
- •Solid Viscosity Model
- •Drag Model
- •Solid Pressure Model
- •Initial Values
- •Boundary, Point, and Pair Conditions for the Euler-Euler Model, Laminar Flow Interface
- •Wall
- •Dispersed Phase Boundary Condition
- •Inlet
- •Two-Phase Inlet Type
- •Continuous Phase
- •Dispersed Phase
- •Outlet
- •Mixture Boundary Condition
- •The Euler-Euler Model Equations
- •References for the Euler-Euler Model, Laminar Flow Interface
- •Selecting the Right Interface
- •The Porous Media Flow Interface Options
- •Coupling to Other Physics Interfaces
- •Discretization
- •Fluid and Matrix Properties
- •Mass Source
- •Mass Source
- •Initial Values
- •Initial Values
- •Boundary Conditions for the Darcy’s Law Interface
- •Pressure
- •Pressure
- •Mass Flux
- •Mass Flux
- •Inflow Boundary
- •Inflow Boundary
- •Symmetry
- •No Flow
- •Discretization
- •Fluid and Matrix Properties
- •Volume Force
- •Volume Force
- •Forchheimer Drag
- •Forchheimer Drag
- •Initial Values
- •Initial Values
- •Mass Source
- •Boundary Conditions for the Brinkman Equations Interface
- •Discretization
- •Fluid Properties
- •Porous Matrix Properties
- •Porous Matrix Properties
- •Forchheimer Drag
- •Forchheimer Drag
- •Volume Force
- •Volume Force
- •Initial Values
- •Initial Values
- •Boundary Conditions for the Free and Porous Media Flow Interface
- •Microfluidic Wall Conditions
- •Boundary Condition
- •Discretization
- •Domain, Boundary, and Pair Conditions for the Two-Phase Darcy’s Law Interface
- •Fluid and Matrix Properties
- •Initial Values
- •Initial Values
- •No Flux
- •Pressure and Saturation
- •Pressure and Saturation
- •Mass Flux
- •Inflow Boundary
- •Inflow Boundary
- •Outflow
- •Pressure
- •Darcy’s Law—Equation Formulation
- •About the Brinkman Equations
- •Brinkman Equations Theory
- •References for the Brinkman Equations Interface
- •Reference for the Free and Porous Media Flow Interface
- •Darcy’s Law—Equation Formulation
- •The High Mach Number Flow, Laminar Flow Interface
- •Surface-to-Surface Radiation
- •Discretization
- •Initial Values
- •Initial Values
- •Shared Interface Features
- •Fluid
- •Dynamic Viscosity
- •Inlet
- •Outlet
- •Consistent Inlet and Outlet Conditions
- •Pseudo Time Stepping for High Mach Number Flow Models
- •References for the High Mach Number Flow Interfaces
- •Selecting the Right Interface
- •The Non-Isothermal Flow Interface Options
- •Coupling to Other Physics Interfaces
- •The Non-Isothermal Flow, Laminar Flow Interface
- •Discretization
- •The Conjugate Heat Transfer, Laminar Flow Interface
- •The Turbulent Flow, Spalart-Allmaras Interface
- •Fluid
- •Dynamic Viscosity
- •Wall
- •Boundary Condition
- •Initial Values
- •Pressure Work
- •Viscous Heating
- •Dynamic Viscosity
- •Turbulent Non-Isothermal Flow Theory
- •References for the Non-Isothermal Flow and Conjugate Heat Transfer Interfaces
- •Selecting the Right Interface
- •The Heat Transfer Interface Options
- •Conjugate Heat Transfer, Laminar Flow
- •Conjugate Heat Transfer, Turbulent Flow
- •Coupling to Other Physics Interfaces
- •Accessing the Heat Transfer Interfaces via the Model Wizard
- •Discretization
- •Heat Transfer in Solids
- •Translational Motion
- •Translational Motion
- •Pressure Work
- •Heat Transfer in Fluids
- •Viscous Heating
- •Dynamic Viscosity
- •Heat Source
- •Heat Source
- •Initial Values
- •Initial Values
- •Boundary Conditions for the Heat Transfer Interfaces
- •Temperature
- •Temperature
- •Thermal Insulation
- •Outflow
- •Symmetry
- •Heat Flux
- •Heat Flux
- •Inflow Heat Flux
- •Inflow Heat Flux
- •Open Boundary
- •Periodic Heat Condition
- •Surface-to-Ambient Radiation
- •Boundary Heat Source
- •Boundary Heat Source
- •Heat Continuity
- •Pair Thin Thermally Resistive Layer
- •Pair Thin Thermally Resistive Layer
- •Thin Thermally Resistive Layer
- •Thin Thermally Resistive Layer
- •Line Heat Source
- •Line Heat Source
- •Point Heat Source
- •Convective Cooling
- •Out-of-Plane Convective Cooling
- •Upside Heat Flux
- •Out-of-Plane Radiation
- •Upside Parameters
- •Out-of-Plane Heat Flux
- •Domain Selection
- •Upside Inward Heat Flux
- •Change Thickness
- •Change Thickness
- •Porous Matrix
- •Heat Transfer in Fluids
- •Thermal Dispersion
- •Dispersivities
- •Heat Source
- •Equation Formulation
- •Activating Out-of-Plane Heat Transfer and Thickness
The High Mach Number Flow, Laminar Flow Interface
The Laminar Flow interface (
), found under the Fluid Flow>High Mach Number Flow branch (
) of the Model Wizard, is a predefined multiphysics coupling consisting of a Laminar Flow interface, using a compressible formulation, in combination with a
Heat Transfer interface. When the interface is added, these nodes are added by default—Fluid, Wall, Thermal Insulation, and Initial Values.
Right-click any node to add other features that implement, for example, boundary conditions, volume forces, or heat sources.
I N T E R F A C E I D E N T I F I E R
The interface identifier is a text string that can be used to reference the respective physics interface if appropriate. Such situations could occur when coupling this interface to another physics interface, or when trying to identify and use variables defined by this physics interface, which is used to reach the fields and variables in expressions, for example. It can be changed to any unique string in the Identifier field.
The default identifier (for the first interface in the model) is hmnf.
D O M A I N S E L E C T I O N
The default setting is to include All domains in the model to define the dependent variables and the equations governing them. To choose specific domains, select Manual from the Selection list.
P H Y S I C A L M O D E L
Define interface properties to control the overall type of model:
Turbulence Model Type
By definition, no turbulence model is needed when studying laminar flows. The default Turbulence model type is None.
The flow state in a fluid-flow model is not, however, always known beforehand. Select
RANS as the Turbulence model type and select k- as Turbulence model in order to account for turbulence. This changes the interface into the turbulent version.
If the default Turbulence model type selected is RANS, the additional turbulence model settings are made available. However, the node is still
called High Mach Number Flow (hmnf) with a number added at the end of
Note
the name to indicate the change.
T H E H I G H M A C H N U M B E R F L O W I N T E R F A C E S | 349
S U R F A C E - T O - S U R F A C E R A D I A T I O N
This check box is available with the Heat Transfer Module license. Select the
Surface-to-surface radiation check box to enable the Radiation Settings section.
R A D I A T I O N S E T T I N G S
|
This section requires an additional Heat Transfer Module license and |
|
displays when the Surface-to-surface radiation check box is selected. See |
Note |
the Heat Transfer Module User’s Guide for details. |
|
|
D E P E N D E N T V A R I A B L E S
The dependent variables (field variables) are for the Velocity field, Pressure, and Temperature. The names can be changed but the names of fields and dependent variables must be unique within a model.
D I S C R E T I Z A T I O N
To display this section, click the Show button (
) and select Discretization. Select a
Discretization of fluids—P1+P1 (the default), P2+P1, or P3+P2.
C O N S I S T E N T A N D I N C O N S I S T E N T S T A B I L I Z A T I O N
To display this section, click the Show button (
) and select Stabilization. Any settings unique to this interface are listed below.
•The consistent stabilization methods are applicable to the Heat and flow equations.
•When the Crosswind diffusion check box is selected, enter a Tuning parameter Ck for one or both of the Heat and flow equations and Turbulence Equations. The default for
the Heat and flow equations is 1, and 1 for the Turbulence equations.
•The Isotropic diffusion inconsistent stabilization method can be activated for both the Heat equation and the Navier-Stokes equations.
•Model Builder Options for Physics Feature Node Settings Windows
•The Heat Transfer Interfaces
•The High Mach Number Flow, Turbulent Flow, k- Interface
See Also |
• |
The High Mach Number Flow, Turbulent Flow, Spalart-Allmaras |
|
|
Interface |
|
• |
Shared Interface Features |
350 | C H A P T E R 1 1 : H I G H M A C H N U M B E R F L O W B R A N C H
The High Mach Number Flow, Turbulent Flow, k- Interface
The Turbulent Flow, k- interface (
), found under the High Mach Number Flow>Turbulent Flow branch (
) in the Model Wizard, is a predefined multiphysics coupling consisting of a Turbulent Flow k- interface, using a compressible formulation, in combination with a Heat Transfer interface. When the interface is added, these nodes are added by default—Fluid, Wall, Thermal Insulation, and Initial Values.
As in Table 11-1, the turbulent versions of the interfaces differ by where they are selected in the Model Wizard and the default Turbulence model selected—k- for this interface.
Right-click any node to add other features that implement, for example, boundary conditions, volume forces, or heat sources.
I N T E R F A C E I D E N T I F I E R
The interface identifier is a text string that can be used to reference the respective physics interface if appropriate. Such situations could occur when coupling this interface to another physics interface, or when trying to identify and use variables defined by this physics interface, which is used to reach the fields and variables in expressions, for example. It can be changed to any unique string in the Identifier edit field.
The default identifier (for the first interface in the model) is hmnf.
D O M A I N S E L E C T I O N
The default setting is to include All domains in the model to define the dependent variables and the equations governing them. To choose specific domains, select Manual from the Selection list.
P H Y S I C A L M O D E L
The default Turbulence model for the Turbulent flow, k- interface is k- .
The default Turbulence model type is RANS and the default Heat transport turbulence model is Kays-Crawford. Or select User defined turbulent Prandtl number. The influence of the turbulent fluctuations on the temperature field are modeled using a turbulent Prandtl number model. A user defined model for the turbulence Prandtl number can always be defined. Enter the user defined value or expression for the turbulence Prandtl number in the Model Inputs section of the Fluid feature node.
T H E H I G H M A C H N U M B E R F L O W I N T E R F A C E S | 351
T U R B U L E N C E M O D E L P A R A M E T E R S
Edit the model parameters of the k- model as required.
D E P E N D E N T V A R I A B L E S
The dependent variables (field variables) are for the Velocity field, Pressure, and
Temperature. For turbulence modeling and heat radiation, there are additional dependent variables for the Turbulent kinetic energy and Turbulent dissipation rate.
The names can be changed but the names of fields and dependent variables must be unique within a model.
C O N S I S T E N T A N D I N C O N S I S T E N T S T A B I L I Z A T I O N
To display this section, click the Show button (
) and select Stabilization. Any settings unique to this interface are listed below.
•The consistent stabilization methods are applicable to the Heat and flow equations and the Turbulence Equations.
•When the Crosswind diffusion check box is selected, enter a Tuning parameter Ck for one or both of the Heat and flow equations and Turbulence Equations. The default for
the Heat and flow equations is 1, and 1 for the Turbulence equations.
•The Isotropic diffusion inconsistent stabilization method can be activated for the Heat equation, Navier-Stokes equations, and the Turbulence equations.
•By default there is no isotropic diffusion selected. If required, select the Isotropic diffusion check box and enter a Tuning parameter id for one or all of Heat equation,
Navier-Stokes equations, or Turbulence equations. The defaults are 0.25.
•Model Builder Options for Physics Feature Node Settings Windows
•The Heat Transfer Interfaces
•The High Mach Number Flow, Laminar Flow Interface
See Also |
• |
The High Mach Number Flow, Turbulent Flow, Spalart-Allmaras |
|
|
Interface |
|
• |
Shared Interface Features |
352 | C H A P T E R 1 1 : H I G H M A C H N U M B E R F L O W B R A N C H