Tools Constants

Within the Constants dialogue box, various values can be changed that are used in many of the calculations.
Default values are set upon program start for Dry Air.

The Gas contant, R ,  is set to 287.06 J / kg K , this is the difference of the Cp and Cv

Zero Celsius can be changed on the Kelvin scale.

The Mach number limit can also be altered.

The local acceleration due to gravity can also be changed, this is used with the Atmosphere calculations

Each of the specific heats, Cp and Cv change with temperature. A best fit curve constants are shown in the SP Heats tab if it is desired to change the response of these due to temperature.

Similarly the Thermal Conductivity of air changes with temperature.
A best fit curve has been plotted and the constants generated.
These can be changed if desired. 
Under the Atmosphere tab the Lapse rate values can be changed for the Atmosphere calculations

The Lapse rate is the rate of decay of the Temperature with altitude

Click the default button at the bottom of the page to set all of these values back to defaults