Hello all,

The calculations for radiant heat transfer between shapes (objects) involves knowledge of the view factor. The view factor is defined as the fraction of the radiation leaving one surface that is intercepted by the other surface. Also, the view factor is a dimensionless number ranging between 0 and 1.

For simple or moderately complex 2 and 3 dimensional configurations the view factors have been worked out analytically and are tabulated in any book on radiation exchange. However, when the configurations get too complex or aren't easily obtained from a table, "a" Monte Carlo integration method is commonly used to obtain them.

My question is: How would I implement the MCintegrate algorithm to perform the numerical calculation of a view factor?

For example, the 2 dimensional configuration of inclined parallel plates of equal width and a common edge has a view factor tabulated as

1 - sin(alpha/2)

where alpha is the angle between the two parallel plates.

So for an alpha = 30 degrees the view factor = 0.741

This means that 74.1% of the radiation leaving the horizontal surface is intercepted by the inclined surface.

I would like to duplicate that result using "a" Monte Carlo method.

The view factor integral is defined in the attachment.

The following parameters would be used in the calculation.

w = 2 (ft) (w is the width of the two plates.)
alpha = 30 degrees (the angle between the two parallel plates.)

Any help on how this could be implemented into the MCintegrate algorithm would be greatly appreciated.

Thanks
Matt