Assistant for powder temperature coefficients

With this assistant, you have the possibility to recalculate analytically the temperature coefficients “tcc” and “tch” of the powder model with your self-measured deviations. The temperature coefficients changes the behavior when entering a temperature different from the normal temperature.

This is very useful if you want to simulate charges at different temperatures as accurately as possible.

The temperature coefficients of a powder model defines the change in burning behavior at extremely cold (tcc) or warm (tch) temperatures of the powder. Nowadays, most propellant powders are temperature-stabilized, nevertheless, they are sometimes acting extremely differently in their performance behavior. If a powder model does not contain values for tcc and tch ( Both values = 0.0000) the GRT-internal default values are used.

The Assistant can read out measured values from a measured value tab. Alternatively, you can enter the measured values manually.

To automatically read out the measurements, simply create a Measurement tab, which contains three measurements of the same charge at different temperatures:

• Charge Cold, e.g. -10°C.
• Charge Normal +21°C (default, must be 21°C / 70°F entered!)
• Charge Hot, e.g. +50°C

Enter your measurement results:

The temperatures you enter in the name or note column, can be in “C” or “°C” for degrees Celsius, or “F” or “°F” for degrees Fahrenheit as units.

For the measurement result at normal temperature, 21°C or 70°F MUST be entered!

Make sure that your powder temperature of the charge is at normal temperature before starting the assistant!

Then click on the yellow star to open the assistant.

The measured values are automatically taken over from the measurement tab you created.

Then click on the button [ Calculate temperature coefficients ]

By clicking on the [ Apply ] button, the calculated coefficients are transferred to your powder data of the load.