ABSTRACT
The incident solar flux was determined by experimentally measuring the solar heat absorbed by a black painted aluminum plate of known solar absorptivity. The experiment was repeated for three angles of incidence. The experimental solar flux was then used to calculate the solar absorptivity of the mill-finish side of the aluminum plate. The temperature profile of the unpainted plate, as it was exposed to the sun, was determined in the same fashion as described earlier. The transient model was again used, but the absorptivity was now determined by iteration, using the experimental solar flux. The solar fluxes were found to decrease with increasing angle of incidence, from 750 to 390 W/m2, as the angle of incidence was increased from 0° to 60°. In measuring the solar absorptivity of mill-finish aluminum, the experimental value of 0.13 was well within the range presented by the EPA.
