34.3.12 Define/Injections...

The Define/Injections... menu item opens the Injections dialog box.

Injections Dialog Box

The Injections dialog box allows you to create, delete, and list discrete phase injections, and access the Set Injection Properties dialog box and the Set Multiple Injection Properties dialog box, in which you can set the properties for the injections. See Section  23.3.14 for details.

Controls

Injections   contains a list from which you can select one or more injections in order to set, copy, or modify properties, or delete or list injections.

Create   creates a new injection and opens the Set Injection Properties dialog box, in which you can set its properties.

Copy   creates a new injection with the same properties as the selected injection and opens the Set Injection Properties dialog box where the new injection's properties can be modified.

Delete   deletes the injection(s) selected in the Injections list.

List   lists the initial conditions for the particle streams in the injection(s) selected in the Injections list.

Read...   opens the Select File dialog box (see Section  2.1.6) where you will select the injection file to read in.

Write...   allows you to select the injection from the list and write it to a file.

Injection Name Pattern   specifies the pattern to look for in the names of injections. Type the pattern in the text field and click Match to select (or deselect) the injections in the Injections list with names that match the specified pattern. See Section  23.3.14 for information about matching additional characters using * and ?.

Set...   opens the Set Injection Properties dialog box for the injection selected in the Injections list or the Set Multiple Injection Properties dialog box if more than one injection is selected in the Injections list.

Set Injection Properties Dialog Box

The Set Injection Properties dialog box allows you to define the properties of an existing discrete-phase injection (which was created in the Injections dialog box). This dialog box is opened from the Injections dialog box. See Section  23.3.15 for details about the items listed in this section.

Controls

Injection Name   sets the name of the injection.

Injection Type   contains a drop-down list of the available injection types: single, group, cone, solid-cone, surface, plain-orifice-atomizer, pressure-swirl-atomizer, air-blast-atomizer, flat-fan-atomizer, effervescent-atomizer, and file. ( cone is not available in 2D.) These choices are described in Section  23.3.1.

Number of Particle Streams   indicates the number of particle streams in a group or cone injection. (This item will not appear for single, surface, or file injections.)

Release From Surfaces   indicates the surface from which the particles in a surface injection will be released. (This item will appear only for a surface injection.)

Particle Type   specifies the particle type as Massless, Inert, Droplet, Combusting, or Multicomponent. These types are described in Section  23.3.2.

Laws   (not for massless particles) contains inputs for customized particle laws.

Custom   enables the specification of customized particle laws and opens the Custom Laws dialog box.

Material   (not for massless particles) indicates the material for the particles. If this is the first time you have created a particle of this type, you can choose from all of the materials of this type defined in the database. If you have already created a particle of this type, the only available material will be the material you selected for that particle. You can define additional materials by copying them from the database or creating them from scratch, as discussed in Section  23.5.2 and described in detail in Section  8.1.2.

Diameter Distribution   (not for massless particles) allows you to change from the default linear interpolation method used to determine the size of the particles in a group injection, or the default uniform method used to determine the size of the particles in a surface injection, to the rosin-rammler or rosin-rammler-logarithmic method. The Rosin-Rammler method for determining the range of diameters is described in Section  23.3.13.

Evaporating Species   (for droplet particles) specifies the gas-phase species created by the vaporization and boiling laws (laws 2 and 3).

Devolatilizing Species   (for combusting particles) specifies the gas-phase species created by the devolatilization law (law 4).

This item will not appear for two-mixture-fraction non-premixed combustion calculations.

Devolatilizing Stream   (for combusting particles) specifies the destination stream for the gas-phase species created by the devolatilization law (law 4).

This item will appear only for two-mixture-fraction non-premixed combustion calculations.

Oxidizing Species   (for combusting particles) specifies the gas phase species that participates in the surface char combustion reaction (law 5).

Product Species   (for combusting particles) specifies the gas-phase species created by the surface char combustion reaction (law 5).

This item will not appear for two-mixture-fraction non-premixed combustion calculations.

Product Stream   (for combusting particles) specifies the destination stream for the gas-phase species created by the surface char combustion reaction (law 5).

This item will appear only for two-mixture-fraction non-premixed combustion calculations.

Discrete Phase Domain   is available when using the Dense Discrete Phase Model, described in Section  24.5.7.

Point Properties   displays the inputs for the point properties for the injection (e.g., position, velocity, diameter, temperature, and mass flow rate). These inputs are described for each injection type in Sections  23.3.3- 23.3.11.

First Point   specifies the first point properties for the injection.

Last Point   specifies the last point properties for the injection.

Turbulent Dispersion   displays the inputs for stochastic tracking and cloud tracking.

Stochastic Tracking   controls the stochastic tracking for turbulent flows. Stochastic tracking includes the effect of turbulent velocity fluctuations on the particle trajectories using the DRW model described in this section in the separate Theory Guide. See Section  23.3.16 for details about the items below.

Discrete Random Walk Model   includes the effect of instantaneous turbulent velocity formulations on the particle trajectories through stochastic method.

Random Eddy Lifetime   specifies that the characteristic lifetime of the eddy is to be random.

Number of Tries   controls the inclusion of turbulent velocity fluctuations.

An input of 1 or greater tells ANSYS FLUENT to include turbulent velocity fluctuations in the particle force balance.

Time Scale Constant   is $C_L$ in this equation in the separate Theory Guide. The default is 0.15; if you use the RSM, a value of 0.3 is recommended.

Cloud Tracking   incorporates the effects of turbulent dispersion on the injection. For details on the following items, see this section in the separate Theory Guide and Section  23.3.16.

Cloud Model   enables particle cloud tracking.

Min. Cloud Diameter   specifies the diameter of the cloud in which the particles enter the domain.

Max. Cloud Diameter   specifies the maximum allowed cloud diameter.

Wet Combustion   displays the inputs for the wet combustion model.

Wet Combustion Model   allows the combusting particles to include an evaporating/boiling material.

Liquid Material   contains a drop-down list of liquid materials that can be chosen as the evaporating/boiling material to be included with the combusting particles.

Liquid Fraction   sets the volume fraction of the liquid present in the particle.

Components   displays the inputs for Multicomponent for use in the definition of the particle injection. For details on the following items, see this section in the separate Theory Guide.

Multicomponent Settings   contains the parameters for specifying multicomponent injections.

Component   specifies the component which is a part of the multicomponent species.

Mass Fraction   specifies the mass fraction of the component in a multicomponent species.

Evaporating Species   specifies the gas-phase species to be evaporated.

Evaporating Stream   specifies the source stream from which the species will be evaporated.

UDF   displays the inputs for User-Defined Functions for use in the definition of the particle injection. For details about user-defined functions, see the separate UDF Manual.

Initialization   contains a drop-down list of available user-defined functions. The UDF that you choose will be used to modify the injection properties at the time the particles are injected into the domain.

Heat/Mass Transfer   allows you to select the UDF that defines the heat or mass transfer.

Multiple Reactions   displays the inputs for Multiple Surface Reactions. See Section  15.3 for details about this model.

Species Mass Fractions   specify the combustible fraction of the combusting particle if you have defined more than one particle surface species. See Section  15.3.3 for details.

File...   opens the Select File dialog box (see Section  2.1.6), in which you can select a file containing the injection definition (when file is selected as the Injection Type).

Set Multiple Injection Properties Dialog Box

The Set Multiple Injection Properties dialog box allows you to set properties that are common to multiple injections. This dialog box is opened when you select more than one injections in the Injections dialog box. See Section  23.3.18 for details about the items below.

Controls

Injections Setup   contains a list of the categories of injection properties that you can set for the injections in the Injections list. These categories correspond to the categories of inputs in the Set Injection Properties dialog box. When you select an item in the Injections Setup list, the dialog box will expand to show the relevant inputs, which are the same as those in the Set Injection Properties dialog box.

Injections   displays an informational list of the injections for which you are setting common properties. These are the injections that you selected in the Injections dialog box.

Custom Laws Dialog Box

The Custom Laws dialog box is used to incorporate user-defined functions (see the separate UDF Manual for details) in place of the default physical laws (1 through 6) used in the heat/mass transfer calculations.

Controls

First Law, Second Law, Third Law, Fourth Law, Fifth Law, Sixth Law   contain drop-down lists in which you can choose a user-defined particle law to replace the standard law.

Switching   contains a drop-down list in which you can select a user-defined function that customizes the way ANSYS FLUENT switches between particle laws.