Summary: Specify a custom base solar heat flux.


The solar flux equation used in Autodesk Simulation CFD is:

q_solar = Solar_Constant * ( sine(A) + 0.25 * sine(2A) )

Using the base solar heat flux in the above expression, maximum solar heat flux is 1002 W/m^2 at an altitude of 69 degrees assuming no pollution, cloud cover, or other obscurants. There are several online calculators that enable calculation of the sun's altitude for a given location and time of day. An example is available at

If a base solar heat flux other than 910 W/m^2 is needed, a custom value can be specified by specifying a value with this flag:

SolarFluxConstant A