when the slat is aligned in the same direction of the solar radiation (0 degree of profile angle in case of 0 degree slat angle and +45 degree of profile angle in case of 45 degree of slat angle).
The effect of slat curvature and thickness can also be seen on the direct-to-diffuse transmittance and reflectance when the blind is fully blocked from the sun (10 degree of profile angle and greater in case of +45 degree of slat angle, 40 degree of profile angle and greater in case of 0 degree of slat angle and 65 degree of profile angle and greater in case of 45 degree of slat angle); the value of the direct-to-diffuse transmittance is lower and the value of the reflectance is higher when compared to the flat slat case.
The effect of slat thickness and its edge is also clearly seen on the optical properties shown in Fig. 9 when the profile angle is between 85 and 90 degree.