Initial Conditions dialog box (Thermal/Flow/SST/ESC/Multiphysics)

Type
Type	Specifies the type of initial conditions to apply to the selected region.Initial TemperatureSpecifies the initial temperature.Initial Fluid Pressure – 3D FlowSpecifies the initial pressure of the fluid.Initial Fluid Velocity – 3D FlowSpecifies the initial velocity of the fluid.Initial Fluid Turbulence – 3D FlowSpecifies the initial turbulence of the fluid.Initial Humidity – 3D FlowSpecifies the initial humidity.Initial Tracer Fluid – 3D FlowSpecifies the initial tracer fluid.Initial Mixture – 3D FlowSpecifies the initial fluid mixture.Initial Immiscible Fluid Mixture – 3D FlowSpecifies the initial immiscible fluid mixture.Initial Water Content – 3D FlowSpecifies the initial water content.
Name
Name	Defines the constraint name.Description opens an editor that lets you type a description for the constraint.
Destination Folder
Constraint Container	Specifies the folder in the Simulation Navigator in which the boundary condition will be stored. The list includes the root container and existing folders that you created using the New Folder command. Examples of a root container include Load Container, Constraint Container, and Simulation Object Container.
Folder Manager	Displays a hierarchical listing of existing folders. To create a new folder, right-click any level of the hierarchy and choose New Folder.
Region / Tracked Fluid Region
The Region group appears when Type is set to anything other than Initial Immiscible Fluid Mixture – 3D Flow.The Tracked Fluid Region group appears when Type is set to Initial Immiscible Fluid Mixture – 3D Flow and lets you select the initial tracked fluid region when you model two-phase, immiscible fluids.
Group Reference	Applies the bursting membrane boundary condition to the selected group.For more information, see Group Reference options.
Select Object	Lets you select the geometry, elements or mesh points on which you specify the initial conditions.Excluded lets you remove individual entities from within your selected object. The software does not apply the simulation object to the excluded elements.Note: The Element Selection Filtering options are available when the Type Filter list on the Top Border bar is set to Elements.
Stacked Smart Selector Methods	Opens the Smart Selector Methods dialog box where you can specify a progression of smart selection filters.For more information, see Smart Selector Methods dialog box.
Region Override
Appears when Type is set to Initial Temperature.
Override Region	Overrides the region with a non-geometric element.Non-Geometric ElementDefines an initial temperature on a non-geometric element. Select an existing non-geometric element modeling object from the list, or click Create Modeling Object to create a new non-geometric element.
Initial Temperature
Appears when Type is set to Initial Temperature.
Temperature	Sets the value of the initial temperature. For more information, see Additional magnitude options.
Initial Pressure
Appears when Type is set to Initial Fluid Pressure – 3D Flow.
Pressure	Sets the initial absolute pressure of the fluid for the selected 3D geometry or elements. For more information, see Additional magnitude options.
Initial Velocity
Appears when Type is set to Initial Fluid Velocity – 3D Flow.
X ComponentY ComponentZ Component	Set the values of the X, Y, and Z components of fluid velocity at the start of the analysis. For more information, see Additional magnitude options.
Initial Turbulence
Appears when Type is set to Initial Fluid Turbulence – 3D Flow.
Turbulence Characteristics	Specifies the method for calculation of initial turbulence quantities in the flow based on available data derived from experiment or standard references.AutomaticLets the solver compute automatically turbulence characteristics.Turbulence Characteristics modeling objectSpecifies the method for calculation initial turbulence quantities through the selected Turbulence Characteristics modeling object.You can also select a previously defined Turbulence Characteristics modeling object from the list or click Create Modeling Object to define a new modeling object.Click Edit to modify the specified modeling object.For more information, see Turbulence Characteristics.
Initial Humidity
Appears when Type is set to Initial Humidity – 3D Flow.
Humidity	Lets you select the method to define the initial humidity. Relative lets you define the initial humidity by specifying Relative Humidity (%) as a percentage of the partial pressure of water vapor in the mixture to the saturated vapor pressure of water at a given temperature. Specific lets you define the initial humidity by specifying the Water Vapor to Dry Air Mass Ratio. See Modeling humidity for more information.
Initial Tracer Fluid
Appears when Type is set to Initial Tracer Fluid – 3D Flow.
Select Tracer Fluid	Lets you select a previously defined Tracer Fluid modeling object to specify the initial value for the tracer fluid, or create a new Tracer Fluid modeling object. See Tracer Fluid for more information.
Tracer Fluid Mass Fraction	Sets the mass fractions for the specified Tracer Fluid modeling object you select in the Select Tracer Fluid list.As a good practice, enter values from 0 to 1 for each mass fraction. The percentage of the main fluid is calculated as 1–∑Mass Fractions.If the sum of the mass fractions you enter is greater than 1, the values are normalized.You can use Cut , Copy , and Paste commands to enter the mass fraction values.
Initial Mixture
Appears when Type is set to Initial Mixture – 3D Flow.
Mixture Mass Fractions	Sets the mass fractions for the gases that you defined in the Homogeneous Gas Mixture modeling objects.As a good practice, enter values from 0 to 1 for each mass fraction. If the sum of the mass fractions you enter is greater than 1, the values are normalized.You can use Cut , Copy , and Paste commands to enter the mass fraction values.
Top/Bottom Surface Water Content
Appears when Type is set to Initial Water Content– 3D Flow.
Water Content	Specifies the method to define initial water content on the top/bottom surface defined by the surfaces.Film ThicknessDefines the value for the initial thickness of the water layer present on the surface. You enter the value in the Film Thickness box.Total MassDefines the value for the initial total mass of the water layer present on the surface. You enter the value in the Total Mass box.Surface DensityDefines the value for the initial mass of water per unit area present on the surface. You enter the value in the Surface Density box.Note: For boundary flow surfaces, the side touching the fluid is always considered the top surface.

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Initial Conditions dialog box (Thermal/Flow/SST/ESC/Multiphysics), Simcenter 3D 2021.1 Series

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