.TAeZoSysPro.HeatTransfer.Functions.fviewFunction

Information

This functions computes the view factor (or called form factor) from the input Areas and with the Carrol's method. To summarize, this method allows to calculate the value of the view factor without knowing the detailed geometry (civil work) but just with the knowing of the value of all the areas. The Carroll's method requires the following hypotheses:

• All surfaces are visible to each other (see theoretical note for details)
• A surface area does not have to theorically exceed 50% of the total area. In the module, the value of 48% is used rather than 50% as margin

The formula of the F_view factor derives to an heuristic relation:

Where :

• F_view_{i or k} is a view factor
• A_wall_{i or k} is a surface area

This heuristic relation is solved iteratively. The convergence criteria (the value of tolerance) is performed on the residuals wich are defined as the norm between the difference vector Fview at iteration N and iteration N-1. The default value for the tolerance is 10^-5.

The convergence is theorically guaranteed if the initial value for fview is 1.

Interface

function fviewFunction
  input Real[:] Awall;
  output Real[size(Awall, 1)] Fview;
end fviewFunction;