Setting of chemical species

Dialog window for definition of chemical species 

Figure 47. Dialog window for definition of chemical species

Choose of chemical species from the list

The dialog window enables creation and management of the chemical species. After any species were already created, they appear in the drop-down list choose chemical species from the list in the top part of the dialog window. Here the specified species can be selected and controlled. After the species item is selected from the list, its name and the name of its transport medium will appear in the dialog. The species settings can be accordingly changed or species can be deleted from the list.

chemical species

The name of the chemical species is indicated in the dialog frame chemical species. The name of the chemical species can changed with the left mouse button. The push of the chemical species button sets the species name equal to the identifier eventually selected in the drop-down list material for species/ transport medium. For details see the description of the corresponding list.

transport medium

The transport medium button defines the material name treated as the transport medium for the considered species. The transport medium can be set and modified in the same way as the species name corresponding to the selected material in the material for species/ transport medium. For details see the description of the corresponding list.

Each chemical species is associated with a single transport medium. If chemically the same species penetrates through the interface separating two transport media in contact, species with different names should be introduced for each transport medium. A heterogeneous chemical reaction at the interface between neighboring media should be considered.

material for species/ transport medium

In this drop-down list all defined materials from the Materials dialog are being included. The materials serve for definition of the transport medium and of the transported chemical species.

For the definition of the chemical species first special materials should be added to the materials list in the Materials dialog. These materials store required information about the physical properties of the corresponding species as diffusion coefficient, density, phase state etc.

For the definition of the transport medium for the species select the material from the considered list and click with the left mouse button on the button transport medium . The identifier on the button will be set equal to this on the material for species/ transport medium button.

For definition of the chemical species select again the corresponding material from the considered list and click with the left mouse button on the button chemical species . The identifier on the button will be set equal to this on the material for species/ transport medium button. The chemical species will obtain the material properties of the material with the same name. The species transport and chemical reactions with the species will be considered inside of regions filled with the material of the transport medium. The second condition is, the regions should be meshed structurally.

account change

After each change in the list of the define chemical species they should be adopted in the dynamically adjustable lists in the other tabs of the dialog reactions and special boundaries. The lists there will be adopted each time after the button account change is pressed.

The account change button doesn't modify the computational chemical model but only sinchronises the user interface. For copying of the chemical data into the computational part f first the chemical model should be completely entered and only then the chemical model data will be transferred to the computational part by pressing the OK or Apply buttons.

add new species

This button adds a new item to the species list in the graphical user interface. After pressing on it the list is expanded by the default entry "new species name" with the transport medium taken over from the last entry in the list. In order to create a meaningful species change the species and transport medium names using the drop-down list "material for species/ transport medium" and the left mouse button and then press account change button.

delete selected species

Pressing of this button deletes the selected species from the GUI list. All species lists are automatically adopted. There is no need for the account change button press in this case.

effect on gas convection

The check box effect on gas convection controls the back coupling between the chemical species and the transport properties of the transport medium. If the check box is activated, than all transport properties for fluid flow and heat transfer are computed according to the semi-empirical expressions for the gas mixtures and the permanent concentrations of all chemical species in the transport medium.

This option will couple the transport equation for momentum and enthalpy with the transport equations for chemical species and chemical reactions together. As a result the chemistry is calculated iteratively in the coupled mode together with solution of the Navier-Stokes equations.

No thermo solutal effect is considered.

HELP

Here a short local manual for setting of the chemistry model including the chemical reaction and special boundary conditions can be found.

Related procedures

Definition of chemical species .