Appendix J THE DIFFERENTIAL EQUATION FOR THE 2D CONCENTRATOR PROFILE WITH NONPLANE ABSORBER
It was shown in Chapter 5 that the concentrator profile that gives the theoretical maximum concentration is obtained in two sections. The first section, that shadowed from the direct rays at angles less than θi, the maximum input angle, is an involute of the absorber cross section. The second section is such that rays at θi are tangent to the absorber after one reflection at the concentrator surface.
We suppose the absorber surface to be specified by its polar coordinates r, θ, as in Figure J.1. The current point P on the profile is at a distance t from the corresponding tangent point on the absorber. The condition for reflection is
Figure J.1 The differential ...