Many optical characteristics of the CPC (compound parabolic concentrator) can be analyzed with remarkable simplicity and elegance if one employs the reciprocity relations of radiative heat transfer. While the characteristics that are of interest for solar energy have been studied extensively, those for lighting and infrared heaters have remained unexplored. The design considerations are quite different from solar applications because the reflector is placed close to the source rather than close to the target. In this note we show that the flux density produced by an untruncated CPC at a point P of a distant target plane is essentially the radiation shape factor from P to the aperture of the CPC - a simple trigonometric expression obtained without detailed ray tracing. Absorption losses can be analyzed with equal simplicity in terms of the average number of reflections. In addition to their usefulness for the reflector configurations in question, the resulting closed form solutions, being exact, can serve as test of the accuracy of ray trace programs.
|Number of pages||11|
|Journal||Proceedings of SPIE - The International Society for Optical Engineering|
|State||Published - 24 Oct 1991|
|Event||Nonimaging Optics: Maximum Efficiency Light Transfer 1991 - San Diego, United States|
Duration: 21 Jul 1991 → …