User Manual

8 - 26
IPN 074-289L
Composer Operating Manual
8.3.11 Gas Properties Database
Pressing the button on the Toolbar or selecting from menu item Tools
>> Gas Properties Database opens the Database dialog. (see Figure 8-11.)
This is where the properties of all the commonly used gases are stored. To step
through the gases, use the scroll bar at the bottom of the window. To add a
material to the database, press the Add New button. Fill in the blanks for the
material's name, molecular weight and gamma. Do not leave any required
entries blank. Your entry will be saved to the database when you hit the OK
button or if you move to another material. To remove a material, use the scroll
bar to select it and then hit the Remove button. The entry will be deleted from
the database. To edit a particular entry, press Edit button after selecting that
entry.
The Freq at 25 °C field cannot be edited and is for reference only. If the vapor
pressure constants, A and B are not known, leave them as zero.
NOTE: The data base parameter, Gamma, is the specific heat ratio referred to
as in Chapter 2; refer to equations [1] and [6] on page 2-2.
Figure 8-11 Gas Properties Database Dialog
γ